diff --git a/res/devtools/syntax/vcm.toml b/res/devtools/syntax/vcm.toml
new file mode 100644
index 00000000..ca05b6a1
--- /dev/null
+++ b/res/devtools/syntax/vcm.toml
@@ -0,0 +1,3 @@
+language = "VCM"
+extensions = ["vcm"]
+line-comment-start = "#"
diff --git a/res/devtools/syntax/xml.toml b/res/devtools/syntax/xml.toml
new file mode 100644
index 00000000..ad591a70
--- /dev/null
+++ b/res/devtools/syntax/xml.toml
@@ -0,0 +1,4 @@
+language = "XML"
+extensions = ["xml"]
+multiline-comment-start = "<!--"
+multiline-comment-end = "-->"
diff --git a/res/layouts/code_editor.xml b/res/layouts/code_editor.xml
index 4336ee4f..4b61c4d8 100644
--- a/res/layouts/code_editor.xml
+++ b/res/layouts/code_editor.xml
@@ -1,12 +1,6 @@
 <splitbox id="editorRoot" orientation="horizontal" split-pos="0.3">
     <splitbox split-pos="0.75">
-        <panel interval="2" color="0" padding="2">
-            <textbox pos="2" padding="4,0,4,0" sub-consumer="filter_files" hint="@Filter"></textbox>
-            <panel id="filesList" color="#00000030" interval="6" padding="4"
-                    size-func="-1,-45" pos="2,38">
-                <!-- content is generated in script -->
-            </panel>
-        </panel>
+        <iframe src="core:files_panel"></iframe>
         <panel id="problemsLog"
             color="#00000030" 
             padding="5,15,5,15">
@@ -14,46 +8,49 @@
         </panel>
     </splitbox>
     <splitbox id="editorContainer" split-pos="0.8">
-        <container color="#00000080" 
-                   onclick="document.editor.focused = true document.editor.caret = -1">
-            <container size-func="-1,30" color="#00000020">
-                <image id="lockIcon" src="gui/lock" tooltip="@Read only"
-                        interactive="true" onclick="unlock_access()"
-                        color="#FFFFFF80" size="16" pos="4,6"
-                        hover-color="#1080FF"></image>
-                <panel orientation="horizontal" gravity="top-right" 
-                        size="60,16" padding="8" interval="8" color="0">
-                    <image id="saveIcon" src="gui/save" tooltip="@Save" 
-                        enabled="false" interactive="true" 
-                        hover-color="#1080FF"
-                        onclick="save_current_file()"
-                        color="#FFFFFF80" size="16"></image>
-                    <image id="infoIcon" src="gui/info" tooltip="@editor.info.tooltip" 
-                        enabled="true" interactive="true" 
-                        color="#FFFFFF80" size="16"></image>
-                    <image id="syncIcon" src="gui/play" tooltip="@Run" 
-                        enabled="true" interactive="true" 
-                        hover-color="#1080FF"
-                        onclick="run_current_file()"
-                        color="#FFFFFF80" size="16"></image>
-                </panel>
-                <label id="title" pos="26,8"></label>
+        <splitbox id="codePanel" orientation="horizontal">
+            <container color="#00000080" cursor="text"
+                    onclick="document.editor.focused = true document.editor.caret = -1">
+                <container size-func="-1,30" color="#00000020">
+                    <image id="lockIcon" src="gui/lock" tooltip="@Read only"
+                            interactive="true" onclick="unlock_access()"
+                            color="#FFFFFF80" size="16" pos="4,6"
+                            hover-color="#1080FF"></image>
+                    <panel orientation="horizontal" gravity="top-right" 
+                            size="60,16" padding="8" interval="8" color="0">
+                        <image id="saveIcon" src="gui/save" tooltip="@Save" 
+                            enabled="false" interactive="true" 
+                            hover-color="#1080FF"
+                            onclick="save_current_file()"
+                            color="#FFFFFF80" size="16"></image>
+                        <image id="infoIcon" src="gui/info" tooltip="@editor.info.tooltip" 
+                            enabled="true" interactive="true" 
+                            color="#FFFFFF80" size="16"></image>
+                        <image id="syncIcon" src="gui/play" tooltip="@Run" 
+                            enabled="true" interactive="true" 
+                            hover-color="#1080FF"
+                            onclick="run_current_file()"
+                            color="#FFFFFF80" size="16"></image>
+                    </panel>
+                    <label id="title" pos="26,8"></label>
+                </container>
+                <textbox
+                    id='editor'
+                    pos='0,30'
+                    color='0'
+                    autoresize='true'
+                    margin='0'
+                    padding='5'
+                    multiline='true'
+                    line-numbers='true'
+                    oncontrolkey='on_control_combination'
+                    size-func="-1,40"
+                    text-wrap='false'
+                    scroll-step='50'
+                ></textbox>
             </container>
-            <textbox
-                id='editor'
-                pos='0,30'
-                color='0'
-                autoresize='true'
-                margin='0'
-                padding='5'
-                multiline='true'
-                line-numbers='true'
-                oncontrolkey='on_control_combination'
-                size-func="-1,40"
-                text-wrap='false'
-                scroll-step='50'
-            ></textbox>
-        </container>
+            <modelviewer id="modelviewer" visible="false" center="0.5,0.5,0.5" cam-rotation="45,-45,0"/>
+        </splitbox>
         <splitbox orientation="horizontal" split-pos="0.4">
             <panel id="traceback" padding="4" color="#000000A0">
             </panel>
diff --git a/res/layouts/code_editor.xml.lua b/res/layouts/code_editor.xml.lua
index 6cb9ce68..de460f2e 100644
--- a/res/layouts/code_editor.xml.lua
+++ b/res/layouts/code_editor.xml.lua
@@ -1,6 +1,5 @@
 local writeables = {}
 local registry
-local filenames
 
 local current_file = {
     filename = "",
@@ -49,6 +48,10 @@ events.on("core:error", function (msg, traceback)
     table.insert(errors_all, full)
 end)
 
+events.on("core:open_in_editor", function(filename, linenum)
+    open_file_in_editor(filename, linenum)
+end)
+
 local function find_mutable(filename)
     local packid = file.prefix(filename)
     if packid == "core" then
@@ -80,16 +83,6 @@ local function refresh_file_title()
         ..(edited and ' *' or '')
 end
 
-function filter_files(text)
-    local filtered = {}
-    for _, filename in ipairs(filenames) do
-        if filename:find(text) then
-            table.insert(filtered, filename)
-        end
-    end
-    build_files_list(filtered, text)
-end
-
 function on_control_combination(keycode)
     if keycode == input.keycode("s") then
         save_current_file()
@@ -111,10 +104,29 @@ function unlock_access()
     )
 end
 
+local function reload_model(filename, name)
+    assets.parse_model("xml", document.editor.text, name)
+end
+
 function run_current_file()
     if not current_file.filename then
         return
     end
+
+    local info = registry.get_info(current_file.filename)
+    local script_type = info and info.type or "file"
+    local unit = info and info.unit
+
+    if script_type == "model" then
+        print(current_file.filename)
+        clear_output()
+        local _, err = pcall(reload_model, current_file.filename, unit)
+        if err then
+            document.output:paste(string.format("\n[#FF0000]%s[#FFFFFF]", err))
+        end
+        return
+    end
+
     local chunk, err = loadstring(document.editor.text, current_file.filename)
     clear_output()
     if not chunk then
@@ -126,9 +138,7 @@ function run_current_file()
         )
         return
     end
-    local info = registry.get_info(current_file.filename)
-    local script_type = info and info.type or "file"
-    local unit = info and info.unit
+
     save_current_file()
 
     local func = function()
@@ -198,6 +208,7 @@ events.on("core:open_traceback", function(traceback_b64)
     tb_list.size = srcsize
 end)
 
+--- Save the current file in the code editor if has writeable path.
 function save_current_file()
     if not current_file.mutable then
         return
@@ -209,7 +220,22 @@ function save_current_file()
     document.editor.edited = false
 end
 
+--- Open a file in the code editor.
+--- @param filename string - the path to the file to open.
+--- @param line integer - the line number to focus on (optional).
+--- @param mutable string - writeable file path (optional).
 function open_file_in_editor(filename, line, mutable)
+    debug.log("opening file " .. string.escape(filename) .. " in editor")
+
+    local ext = file.ext(filename)
+    if ext == "xml" or ext == "vcm" then
+        document.modelviewer.src = file.stem(filename)
+        document.modelviewer.visible = true
+    else
+        document.modelviewer.visible = false
+    end
+    document.codePanel:refresh()
+
     local editor = document.editor
     local source = file.read(filename):gsub('\t', '    ')
     editor.scroll = 0
@@ -229,43 +255,11 @@ function open_file_in_editor(filename, line, mutable)
     document.saveIcon.enabled = current_file.modified
 end
 
-function build_files_list(filenames, selected)
-    local files_list = document.filesList
-    files_list.scroll = 0
-    files_list:clear()
-
-    for _, actual_filename in ipairs(filenames) do
-        local filename = actual_filename
-        if selected then
-            filename = filename:gsub(selected, "**"..selected.."**")
-        end
-        local parent = file.parent(filename)
-        local info = registry.get_info(actual_filename)
-        local icon = "file"
-        if info then
-            icon = info.type == "component" and "entity" or info.type
-        end
-        files_list:add(gui.template("script_file", {
-            path = parent .. (parent[#parent] == ':' and '' or '/'), 
-            name = file.name(filename),
-            icon = icon,
-            unit = info and info.unit or '',
-            filename = actual_filename
-        }))
-    end
-end
-
 function on_open(mode)
     registry = require "core:internal/scripts_registry"
-    
-    local files_list = document.filesList
 
-    document.editorContainer:setInterval(200, refresh_file_title)
+    document.codePanel:setInterval(200, refresh_file_title)
 
     clear_traceback()
     clear_output()
-
-    filenames = registry.filenames
-    table.sort(filenames)
-    build_files_list(filenames)
 end
diff --git a/res/layouts/console.xml b/res/layouts/console.xml
index 16fbbb0b..3772d240 100644
--- a/res/layouts/console.xml
+++ b/res/layouts/console.xml
@@ -22,8 +22,7 @@
             markup="md"
         ></textbox>
     </container>
-    <iframe id="editorRoot" pos="0,30" size-func="-1,gui.get_viewport()[2]-30" 
-            src="core:code_editor">
+    <iframe id="editorRoot" pos="0,30" size-func="-1,gui.get_viewport()[2]-30">
     </iframe>
     <textbox id='prompt' 
              consumer='submit' 
diff --git a/res/layouts/console.xml.lua b/res/layouts/console.xml.lua
index 3617c08a..94cbda8b 100644
--- a/res/layouts/console.xml.lua
+++ b/res/layouts/console.xml.lua
@@ -104,8 +104,10 @@ function set_mode(mode)
 
     if mode == 'debug' then
         document.root.color = {16, 18, 20, 220}
+        document.editorRoot.src = "core:code_editor"
     else
         document.root.color = {0, 0, 0, 128}
+        document.editorRoot.src = ""
     end
 
     document.prompt.visible = show_prompt
diff --git a/res/layouts/files_panel.xml b/res/layouts/files_panel.xml
new file mode 100644
index 00000000..680b3e43
--- /dev/null
+++ b/res/layouts/files_panel.xml
@@ -0,0 +1,7 @@
+<panel interval="2" color="0" padding="2">
+    <textbox pos="2" padding="4,0,4,0" sub-consumer="filter_files" hint="@Filter"></textbox>
+    <panel id="filesList" color="#00000030" interval="6" padding="4"
+            size-func="-1,-45" pos="2,38">
+        <!-- content is generated in script -->
+    </panel>
+</panel>
diff --git a/res/layouts/files_panel.xml.lua b/res/layouts/files_panel.xml.lua
new file mode 100644
index 00000000..a4d6ca39
--- /dev/null
+++ b/res/layouts/files_panel.xml.lua
@@ -0,0 +1,54 @@
+local registry
+local filenames
+
+function filter_files(text)
+    local pattern_safe = text:pattern_safe();
+    local filtered = {}
+    for _, filename in ipairs(filenames) do
+        if filename:find(pattern_safe) then
+            table.insert(filtered, filename)
+        end
+    end
+    build_files_list(filtered, pattern_safe)
+end
+
+function open_file_in_editor(filename, linenum)
+    events.emit("core:open_in_editor", filename, linenum)
+end
+
+function build_files_list(filenames, highlighted_part)
+    local files_list = document.filesList
+    files_list.scroll = 0
+    files_list:clear()
+
+    for _, actual_filename in ipairs(filenames) do
+        local filename = actual_filename
+        if highlighted_part then
+            filename = filename:gsub(highlighted_part, "**"..highlighted_part.."**")
+        end
+        local parent = file.parent(filename)
+        local info = registry.get_info(actual_filename)
+        local icon = "file"
+        if info then
+            icon = info.type == "component" and "entity" or info.type
+        end
+        files_list:add(gui.template("script_file", {
+            path = parent .. (parent[#parent] == ':' and '' or '/'), 
+            name = file.name(filename),
+            icon = icon,
+            unit = info and info.unit or '',
+            filename = actual_filename,
+            open_func = "open_file_in_editor",
+        }))
+    end
+end
+
+function on_open(mode)
+    registry = require "core:internal/scripts_registry"
+    
+    local files_list = document.filesList
+
+    filenames = registry.filenames
+    table.sort(filenames)
+    build_files_list(filenames)
+end
diff --git a/res/layouts/templates/script_file.xml b/res/layouts/templates/script_file.xml
index 94e1afd2..f5d55729 100644
--- a/res/layouts/templates/script_file.xml
+++ b/res/layouts/templates/script_file.xml
@@ -3,7 +3,7 @@
     <label hover-color='#30A0FF'
         pos="20,2"
         interactive="true"
-        onclick='open_file_in_editor("%{filename}")'
+        onclick='%{open_func}("%{filename}")'
         markup='md'
         tooltip='%{unit}'
         sizefunc="-1,-1">
diff --git a/res/models/stairs.vcm b/res/models/stairs.vcm
new file mode 100644
index 00000000..2027c09e
--- /dev/null
+++ b/res/models/stairs.vcm
@@ -0,0 +1,4 @@
+@box from (0,0,0) to (1,0.5,1) delete (top,south)
+@box from (0,0.5,0) to (1,1,0.5) delete (bottom,south)
+@rect from (0,0.5,0.5) right (1,0,0) up (0,0,0.5) texture "$2"
+@rect from (0,0,0) right (1,0,0) up (0,1,0) texture "$1"
diff --git a/res/modules/internal/scripts_registry.lua b/res/modules/internal/scripts_registry.lua
index 8933c971..ef347159 100644
--- a/res/modules/internal/scripts_registry.lua
+++ b/res/modules/internal/scripts_registry.lua
@@ -1,6 +1,6 @@
 local export = {
     filenames = {},
-    classification = {}
+    registry = {}
 }
 
 local function collect_components(dirname, dest)
@@ -9,7 +9,7 @@ local function collect_components(dirname, dest)
         for i, filename in ipairs(files) do
             if file.ext(filename) == "lua" then
                 table.insert(dest, filename)
-                export.classification[filename] = {
+                export.registry[filename] = {
                     type="component", 
                     unit=file.prefix(filename)..":"..file.stem(filename)
                 }
@@ -33,13 +33,13 @@ local function collect_scripts(dirname, dest, ismodule)
     end
 end
 
-local function load_scripts_list()
-    local packs = pack.get_installed()
+local function load_scripts_list(packs)
+    local registry = export.registry
     for _, packid in ipairs(packs) do
         collect_scripts(packid..":modules", export.filenames, true)
     end
     for _, filename in ipairs(export.filenames) do
-        export.classification[filename] = {
+        registry[filename] = {
             type="module", 
             unit=file.join(file.parent(file.prefix(filename)..":"..
                            filename:sub(filename:find("/")+1)),
@@ -51,27 +51,39 @@ local function load_scripts_list()
     end
 end
 
-function export.build_classification()
-    local classification = {}
+local function load_models_list(packs)
+    local registry = export.registry
+    for _, filename in ipairs(file.list("models")) do
+        local ext = file.ext(filename)
+        if ext == "xml" or ext == "vcm" then
+            registry[filename] = {type="model", unit=file.stem(filename)}
+            table.insert(export.filenames, filename)
+        end
+    end
+end
+
+function export.build_registry()
+    local registry = {}
     for id, props in pairs(block.properties) do
-        classification[props["script-file"]] = {type="block", unit=block.name(id)}
+        registry[props["script-file"]] = {type="block", unit=block.name(id)}
     end
     for id, props in pairs(item.properties) do
-        classification[props["script-file"]] = {type="item", unit=item.name(id)}
+        registry[props["script-file"]] = {type="item", unit=item.name(id)}
     end
     local packs = pack.get_installed()
     for _, packid in ipairs(packs) do
-        classification[packid..":scripts/world.lua"] = {type="world", unit=packid}
-        classification[packid..":scripts/hud.lua"] = {type="hud", unit=packid}
+        registry[packid..":scripts/world.lua"] = {type="world", unit=packid}
+        registry[packid..":scripts/hud.lua"] = {type="hud", unit=packid}
     end
-    export.classification = classification
+    export.registry = registry
     export.filenames = {}
 
-    load_scripts_list()
+    load_scripts_list(packs)
+    load_models_list(packs)
 end
 
 function export.get_info(filename)
-    return export.classification[filename]
+    return export.registry[filename]
 end
 
 return export
diff --git a/res/scripts/post_content.lua b/res/scripts/post_content.lua
index 85d7b28a..249ed65c 100644
--- a/res/scripts/post_content.lua
+++ b/res/scripts/post_content.lua
@@ -63,4 +63,4 @@ cache_names(block)
 cache_names(item)
 
 local scripts_registry = require "core:internal/scripts_registry"
-scripts_registry.build_classification()
+scripts_registry.build_registry()
diff --git a/res/scripts/stdlib.lua b/res/scripts/stdlib.lua
index 3bc2147e..8915c2b1 100644
--- a/res/scripts/stdlib.lua
+++ b/res/scripts/stdlib.lua
@@ -523,9 +523,6 @@ function time.post_runnable(runnable)
     table.insert(__post_runnables, runnable)
 end
 
-assets = {}
-assets.load_texture = core.__load_texture
-
 -- --------- Deprecated functions ------ --
 local function wrap_deprecated(func, name, alternatives)
     return function (...)
diff --git a/src/assets/assetload_funcs.cpp b/src/assets/assetload_funcs.cpp
index 2afae28c..db77e354 100644
--- a/src/assets/assetload_funcs.cpp
+++ b/src/assets/assetload_funcs.cpp
@@ -1,5 +1,6 @@
 #include "assetload_funcs.hpp"
 
+#include <array>
 #include <filesystem>
 #include <iostream>
 #include <stdexcept>
@@ -10,6 +11,7 @@
 #include "coders/imageio.hpp"
 #include "coders/json.hpp"
 #include "coders/obj.hpp"
+#include "coders/vcm.hpp"
 #include "coders/vec3.hpp"
 #include "constants.hpp"
 #include "debug/Logger.hpp"
@@ -300,7 +302,8 @@ assetload::postfunc assetload::sound(
 
 static void request_textures(AssetsLoader* loader, const model::Model& model) {
     for (auto& mesh : model.meshes) {
-        if (mesh.texture.find('$') == std::string::npos) {
+        if (mesh.texture.find('$') == std::string::npos &&
+            mesh.texture.find(':') == std::string::npos) {
             auto filename = TEXTURES_FOLDER + "/" + mesh.texture;
             loader->add(
                 AssetType::TEXTURE, filename, mesh.texture, nullptr
@@ -337,9 +340,40 @@ assetload::postfunc assetload::model(
         };
     }
     path = paths.find(file + ".obj");
+    if (io::exists(path)) {
+        auto text = io::read_string(path);
+        try {
+            auto model = obj::parse(path.string(), text).release();
+            return [=](Assets* assets) {
+                request_textures(loader, *model);
+                assets->store(std::unique_ptr<model::Model>(model), name);
+            };
+        } catch (const parsing_error& err) {
+            std::cerr << err.errorLog() << std::endl;
+            throw;
+        }
+    }
+
+    std::array<std::string, 2> extensions {
+        ".xml",
+        ".vcm"
+    };
+
+    path = "";
+    for (const auto& ext : extensions) {
+        auto newPath = paths.find(file + ext);
+        if (io::exists(newPath)) {
+            path = std::move(newPath);
+            break;
+        }
+    }
+    if (path.empty()) {
+        throw std::runtime_error("could not to find model " + util::quote(file));
+    }
+
     auto text = io::read_string(path);
     try {
-        auto model = obj::parse(path.string(), text).release();
+        auto model = vcm::parse(path.string(), text).release();
         return [=](Assets* assets) {
             request_textures(loader, *model);
             assets->store(std::unique_ptr<model::Model>(model), name);
diff --git a/src/assets/assets_util.cpp b/src/assets/assets_util.cpp
index a2c68363..ee51d53b 100644
--- a/src/assets/assets_util.cpp
+++ b/src/assets/assets_util.cpp
@@ -9,7 +9,11 @@ util::TextureRegion util::get_texture_region(
 ) {
     size_t sep = name.find(':');
     if (sep == std::string::npos) {
-        return {assets.get<Texture>(name), UVRegion(0,0,1,1)};
+        auto texture = assets.get<Texture>(name);
+        if (texture == nullptr && !fallback.empty()) {
+            return util::get_texture_region(assets, fallback, "");
+        }
+        return {texture, UVRegion(0,0,1,1)};
     } else {
         auto atlas = assets.get<Atlas>(name.substr(0, sep));
         if (atlas) {
diff --git a/src/coders/vcm.cpp b/src/coders/vcm.cpp
new file mode 100644
index 00000000..20c50982
--- /dev/null
+++ b/src/coders/vcm.cpp
@@ -0,0 +1,161 @@
+#include "vcm.hpp"
+
+#include <iostream>
+
+#include "xml.hpp"
+#include "util/stringutil.hpp"
+#include "graphics/commons/Model.hpp"
+#include "io/io.hpp"
+
+using namespace vcm;
+using namespace xml;
+
+static const std::unordered_map<std::string, int> side_indices {
+    {"north", 0},
+    {"south", 1},
+    {"top", 2},
+    {"bottom", 3},
+    {"west", 4},
+    {"east", 5},
+};
+
+static void perform_rect(const xmlelement& root, model::Model& model) {
+    auto from = root.attr("from").asVec3();
+    auto right = root.attr("right").asVec3();
+    auto up = root.attr("up").asVec3();
+
+    right *= -1;
+    from -= right;
+
+    UVRegion region {};
+    if (root.has("region")) {
+        region.set(root.attr("region").asVec4());
+    } else {
+        region.scale(glm::length(right), glm::length(up));
+    }
+    if (root.has("region-scale")) {
+        region.scale(root.attr("region-scale").asVec2());
+    }
+
+    auto flip = root.attr("flip", "").getText();
+    if (flip == "h") {
+        std::swap(region.u1, region.u2);
+        right *= -1;
+        from -= right;
+    } else if (flip == "v") {
+        std::swap(region.v1, region.v2);
+        up *= -1;
+        from -= up;
+    }
+    std::string texture = root.attr("texture", "$0").getText();
+    auto& mesh = model.addMesh(texture);
+
+    auto normal = glm::cross(glm::normalize(right), glm::normalize(up));
+    mesh.addRect(
+        from + right * 0.5f + up * 0.5f,
+        right * 0.5f,
+        up * 0.5f,
+        normal,
+        region
+    );
+}
+
+static void perform_box(const xmlelement& root, model::Model& model) {
+    auto from = root.attr("from").asVec3();
+    auto to = root.attr("to").asVec3();
+
+    UVRegion regions[6] {};
+    regions[0].scale(to.x - from.x, to.y - from.y);
+    regions[1].scale(from.x - to.x, to.y - from.y);
+    regions[2].scale(to.x - from.x, to.z - from.z);
+    regions[3].scale(from.x - to.x, to.z - from.z);
+    regions[4].scale(to.z - from.z, to.y - from.y);
+    regions[5].scale(from.z - to.z, to.y - from.y);
+
+    auto center = (from + to) * 0.5f;
+    auto halfsize = (to - from) * 0.5f;
+
+    std::string texfaces[6] {"$0","$1","$2","$3","$4","$5"};
+
+    for (const auto& elem : root.getElements()) {
+        if (elem->getTag() == "part") {
+            // todo: replace by expression parsing
+            auto tags = util::split(elem->attr("tags").getText(), ',');
+            for (auto& tag : tags) {
+                util::trim(tag);
+                const auto& found = side_indices.find(tag);
+                if (found == side_indices.end()) {
+                    continue;
+                }
+                int idx = found->second;
+                if (elem->has("texture")) {
+                    texfaces[idx] = elem->attr("texture").getText();
+                }
+                if (elem->has("region")) {
+                    regions[idx].set(elem->attr("region").asVec4());
+                }
+                if (elem->has("region-scale")) {
+                    regions[idx].scale(elem->attr("region-scale").asVec2());
+                }
+            }
+        }
+    }
+
+    bool deleted[6] {};
+    if (root.has("delete")) {
+        // todo: replace by expression parsing
+        auto names = util::split(root.attr("delete").getText(), ',');
+        for (auto& name : names) {
+            util::trim(name);
+            const auto& found = side_indices.find(name);
+            if (found != side_indices.end()) {
+                deleted[found->second] = true;
+            }
+        }
+    }
+
+    for (int i = 0; i < 6; i++) {
+        if (deleted[i]) {
+            continue;
+        }
+        bool enabled[6] {};
+        enabled[i] = true;
+        auto& mesh = model.addMesh(texfaces[i]);
+        mesh.addBox(center, halfsize, regions, enabled);
+    }
+}
+
+static std::unique_ptr<model::Model> load_model(const xmlelement& root) {
+    model::Model model;
+
+    for (const auto& elem : root.getElements()) {
+        auto tag = elem->getTag();
+
+        if (tag == "rect") {
+            perform_rect(*elem, model);
+        } else if (tag == "box") {
+            perform_box(*elem, model);
+        }
+    }
+
+    return std::make_unique<model::Model>(std::move(model));
+}
+
+std::unique_ptr<model::Model> vcm::parse(
+    std::string_view file, std::string_view src
+) {
+    try {
+        auto doc = io::path(std::string(file)).extension() == ".xml" 
+                    ? xml::parse(file, src) : xml::parse_vcm(file, src, "model");
+        const auto& root = *doc->getRoot();
+        if (root.getTag() != "model") {
+            throw std::runtime_error(
+                "'model' tag expected as root, got '" + root.getTag() + "'"
+            );
+        }
+        std::cout << xml::stringify(*doc) << std::endl;
+        return load_model(root);
+    } catch (const parsing_error& err) {
+        throw std::runtime_error(err.errorLog());
+    }
+}
diff --git a/src/coders/vcm.hpp b/src/coders/vcm.hpp
new file mode 100644
index 00000000..6f239604
--- /dev/null
+++ b/src/coders/vcm.hpp
@@ -0,0 +1,12 @@
+#pragma once
+
+#include <memory>
+#include <string>
+
+namespace model {
+    struct Model;
+}
+
+namespace vcm {
+    std::unique_ptr<model::Model> parse(std::string_view file, std::string_view src);
+}
diff --git a/src/coders/xml.cpp b/src/coders/xml.cpp
index 9ed51e0c..0763fa43 100644
--- a/src/coders/xml.cpp
+++ b/src/coders/xml.cpp
@@ -355,6 +355,83 @@ std::unique_ptr<Document> xml::parse(
     return parser.parse();
 }
 
+namespace {
+class VcmParser : public BasicParser<char> {
+public:
+    VcmParser(std::string_view filename, std::string_view source)
+        : BasicParser(filename, source) {
+        document = std::make_unique<Document>("1.0", "UTF-8");
+        hashComment = true;
+    }
+
+    std::string parseValue() {
+        char c = peek();
+        if (c == '"' || c == '\'') {
+            nextChar();
+            return parseString(c);
+        }
+        if (c == '(') {
+            nextChar();
+            // TODO: replace with array parsing after moving to dv::value's
+            std::string value = std::string(readUntil(')'));
+            expect(')');
+            return value;
+        }
+        return std::string(readUntilWhitespace());
+    }
+
+    void parseSubElements(Node& node) {
+        skipWhitespace();
+        while (hasNext()) {
+            if (peek() != '@') {
+                throw error("unexpected character in element");
+            }
+            nextChar();
+            auto subnodePtr = std::make_unique<Node>(parseName());
+            auto subnode = subnodePtr.get();
+            node.add(std::move(subnodePtr));
+
+            skipWhitespace();
+            while (hasNext() && peek() != '@' && peek() != '{' && peek() != '}') {
+                std::string attrname = parseName();
+                skipWhitespace();
+                std::string value = parseValue();
+                subnode->set(attrname, value);
+                skipWhitespace();
+            }
+            if (!hasNext()) {
+                break;
+            }
+            char c = peek();
+            if (c == '{') {
+                nextChar();
+                parseSubElements(*subnode);
+                expect('}');
+                skipWhitespace();
+            } else if (c == '}') {
+                break;
+            }
+        }
+    }
+
+    std::unique_ptr<Document> parse(const std::string& rootTag) {
+        auto root = std::make_unique<Node>(rootTag);
+        parseSubElements(*root);
+        document->setRoot(std::move(root));
+        return std::move(document);
+    }
+private:
+    std::unique_ptr<Document> document;
+};
+}
+
+std::unique_ptr<Document> xml::parse_vcm(
+    std::string_view filename, std::string_view source, std::string_view tag
+) {
+    VcmParser parser(filename, source);
+    return parser.parse(std::string(tag));
+}
+
 inline void newline(
     std::stringstream& ss, bool nice, const std::string& indentStr, int indent
 ) {
diff --git a/src/coders/xml.hpp b/src/coders/xml.hpp
index f626dd34..24cf0fbd 100644
--- a/src/coders/xml.hpp
+++ b/src/coders/xml.hpp
@@ -126,5 +126,9 @@ namespace xml {
         std::string_view filename, std::string_view source
     );
 
+    std::unique_ptr<Document> parse_vcm(
+        std::string_view filename, std::string_view source, std::string_view tag
+    );
+
     using xmlelement = Node;
 }
diff --git a/src/frontend/ContentGfxCache.cpp b/src/frontend/ContentGfxCache.cpp
index 31199a90..412a3f63 100644
--- a/src/frontend/ContentGfxCache.cpp
+++ b/src/frontend/ContentGfxCache.cpp
@@ -37,17 +37,15 @@ void ContentGfxCache::refresh(const Block& def, const Atlas& atlas) {
     }
     if (def.model.type == BlockModelType::CUSTOM) {
         auto model = assets.require<model::Model>(def.model.name);
-        // temporary dirty fix tbh
-        if (def.model.name.find(':') == std::string::npos) {
-            for (auto& mesh : model.meshes) {
-                size_t pos = mesh.texture.find(':');
-                if (pos == std::string::npos) {
-                    continue;
-                }
-                if (auto region = atlas.getIf(mesh.texture.substr(pos+1))) {
-                    for (auto& vertex : mesh.vertices) {
-                        vertex.uv = region->apply(vertex.uv);
-                    }
+
+        for (auto& mesh : model.meshes) {
+            size_t pos = mesh.texture.find(':');
+            if (pos == std::string::npos) {
+                continue;
+            }
+            if (auto region = atlas.getIf(mesh.texture.substr(pos+1))) {
+                for (auto& vertex : mesh.vertices) {
+                    vertex.uv = region->apply(vertex.uv);
                 }
             }
         }
diff --git a/src/graphics/commons/Model.cpp b/src/graphics/commons/Model.cpp
index 12888d32..20d90eb4 100644
--- a/src/graphics/commons/Model.cpp
+++ b/src/graphics/commons/Model.cpp
@@ -39,6 +39,22 @@ void Mesh::addPlane(
     vertices.push_back({pos-right+up, {uv.u1, uv.v2}, norm});
 }
 
+void Mesh::addRect(
+    const glm::vec3& pos,
+    const glm::vec3& right,
+    const glm::vec3& up,
+    const glm::vec3& norm,
+    const UVRegion& uv
+) {
+    vertices.push_back({pos-right-up, {uv.u1, uv.v1}, norm});
+    vertices.push_back({pos+right-up, {uv.u2, uv.v1}, norm});
+    vertices.push_back({pos+right+up, {uv.u2, uv.v2}, norm});
+
+    vertices.push_back({pos-right-up, {uv.u1, uv.v1}, norm});
+    vertices.push_back({pos+right+up, {uv.u2, uv.v2}, norm});
+    vertices.push_back({pos-right+up, {uv.u1, uv.v2}, norm});
+}
+
 void Mesh::addBox(const glm::vec3& pos, const glm::vec3& size) {
     addPlane(pos+Z*size, X*size, Y*size, Z);
     addPlane(pos-Z*size, -X*size, Y*size, -Z);
@@ -51,16 +67,23 @@ void Mesh::addBox(const glm::vec3& pos, const glm::vec3& size) {
 }
 
 void Mesh::addBox(
-    const glm::vec3& pos, const glm::vec3& size, const UVRegion (&uvs)[6]
+    const glm::vec3& pos,
+    const glm::vec3& size,
+    const UVRegion (&uvs)[6],
+    const bool enabledSides[6]
 ) {
-    addPlane(pos+Z*size, X*size, Y*size, Z, uvs[0]);
-    addPlane(pos-Z*size, -X*size, Y*size, -Z, uvs[1]);
-
-    addPlane(pos+Y*size, X*size, -Z*size, Y, uvs[2]);
-    addPlane(pos-Y*size, X*size, Z*size, -Y, uvs[3]);
-
-    addPlane(pos+X*size, -Z*size, Y*size, X, uvs[4]);
-    addPlane(pos-X*size, Z*size, Y*size, -X, uvs[5]);
+    if (enabledSides[0]) // north
+        addPlane(pos+Z*size, X*size, Y*size, Z, uvs[0]);
+    if (enabledSides[1]) // south
+        addPlane(pos-Z*size, -X*size, Y*size, -Z, uvs[1]);
+    if (enabledSides[2]) // top
+        addPlane(pos+Y*size, X*size, -Z*size, Y, uvs[2] * glm::vec2(-1));
+    if (enabledSides[3]) // bottom
+        addPlane(pos-Y*size, X*size, Z*size, -Y, uvs[3] * glm::vec2(-1, 1));
+    if (enabledSides[4]) // west
+        addPlane(pos+X*size, -Z*size, Y*size, X, uvs[4]);
+    if (enabledSides[5]) // east
+        addPlane(pos-X*size, Z*size, Y*size, -X, uvs[5] * glm::vec2(-1, 1));
 }
 
 void Mesh::scale(const glm::vec3& size) {
diff --git a/src/graphics/commons/Model.hpp b/src/graphics/commons/Model.hpp
index da295cbb..0aed1b76 100644
--- a/src/graphics/commons/Model.hpp
+++ b/src/graphics/commons/Model.hpp
@@ -31,11 +31,19 @@ namespace model {
             const glm::vec3& norm,
             const UVRegion& region
         );
+        void addRect(
+            const glm::vec3& pos,
+            const glm::vec3& right,
+            const glm::vec3& up,
+            const glm::vec3& norm,
+            const UVRegion& region
+        );
         void addBox(const glm::vec3& pos, const glm::vec3& size);
         void addBox(
             const glm::vec3& pos,
             const glm::vec3& size,
-            const UVRegion (&texfaces)[6]
+            const UVRegion (&texfaces)[6],
+            const bool enabledSides[6]
         );
         void scale(const glm::vec3& size);
     };
@@ -47,6 +55,11 @@ namespace model {
         /// @param texture texture name
         /// @return writeable Mesh
         Mesh& addMesh(const std::string& texture) {
+            for (auto& mesh : meshes) {
+                if (mesh.texture == texture) {
+                    return mesh;
+                }
+            }
             meshes.push_back({texture, {}});
             return meshes[meshes.size()-1];
         }
diff --git a/src/graphics/core/Batch3D.cpp b/src/graphics/core/Batch3D.cpp
index 43d161f6..327bb690 100644
--- a/src/graphics/core/Batch3D.cpp
+++ b/src/graphics/core/Batch3D.cpp
@@ -6,6 +6,11 @@
 #include "typedefs.hpp"
 #include "maths/UVRegion.hpp"
 
+namespace {
+    const glm::vec3 SUN_VECTOR(0.528265f, 0.833149f, -0.163704f);
+    const float DIRECTIONAL_LIGHT_FACTOR = 0.3f;
+}
+
 Batch3D::Batch3D(size_t capacity)
     : capacity(capacity) {
 
@@ -31,20 +36,28 @@ void Batch3D::begin(){
 }
 
 void Batch3D::vertex(
-    float x, float y, float z, float u, float v,
-    float r, float g, float b, float a
+    float x,
+    float y,
+    float z,
+    float u,
+    float v,
+    float r,
+    float g,
+    float b,
+    float a
 ) {
     buffer[index].position = {x, y, z};
-    buffer[index].uv = {u, v};
+    buffer[index].uv = {
+        u * region.getWidth() + region.u1, v * region.getHeight() + region.v1};
     buffer[index].color = {r, g, b, a};
     index++;
 }
 void Batch3D::vertex(
-    glm::vec3 coord, float u, float v,
-    float r, float g, float b, float a
+    glm::vec3 coord, float u, float v, float r, float g, float b, float a
 ) {
     buffer[index].position = coord;
-    buffer[index].uv = {u, v};
+    buffer[index].uv = {
+        u * region.getWidth() + region.u1, v * region.getHeight() + region.v1};
     buffer[index].color = {r, g, b, a};
     index++;
 }
@@ -54,7 +67,9 @@ void Batch3D::vertex(
     float r, float g, float b, float a
 ) {
     buffer[index].position = point;
-    buffer[index].uv = uvpoint;
+    buffer[index].uv = {
+        uvpoint.x * region.getWidth() + region.u1,
+        uvpoint.y * region.getHeight() + region.v1};
     buffer[index].color = {r, g, b, a};
     index++;
 }
@@ -86,14 +101,18 @@ void Batch3D::face(
 }
 
 void Batch3D::texture(const Texture* new_texture){
-    if (currentTexture == new_texture)
+    if (currentTexture == new_texture) {
         return;
+    }
     flush();
     currentTexture = new_texture;
-    if (new_texture == nullptr)
+    if (new_texture == nullptr) {
         blank->bind();
-    else
+        region = blank->getUVRegion();
+    } else {
         new_texture->bind();
+        region = currentTexture->getUVRegion();
+    }
 }
 
 void Batch3D::sprite(
@@ -240,6 +259,16 @@ void Batch3D::blockCube(
     cube((1.0f - size) * -0.5f, size, texfaces, tint, shading);
 }
 
+void Batch3D::setRegion(UVRegion region) {
+    this->region = region;
+}
+
+void Batch3D::vertex(const glm::vec3& pos, const glm::vec2& uv, const glm::vec3& norm) {
+    float d = glm::dot(glm::normalize(norm), SUN_VECTOR);
+    d = (1.0f - DIRECTIONAL_LIGHT_FACTOR) + d * DIRECTIONAL_LIGHT_FACTOR;
+    vertex(pos, uv, glm::vec4(d, d, d, 1.0f));
+}
+
 void Batch3D::vertex(
     const glm::vec3& coord, const glm::vec2& uv, const glm::vec4& tint
 ) {
diff --git a/src/graphics/core/Batch3D.hpp b/src/graphics/core/Batch3D.hpp
index c3fb3775..88bec3e4 100644
--- a/src/graphics/core/Batch3D.hpp
+++ b/src/graphics/core/Batch3D.hpp
@@ -3,6 +3,7 @@
 #include "typedefs.hpp"
 #include "commons.hpp"
 #include "MeshData.hpp"
+#include "maths/UVRegion.hpp"
 
 #include <memory>
 #include <cstdlib>
@@ -32,8 +33,8 @@ class Batch3D : public Flushable {
     std::unique_ptr<Texture> blank;
     size_t index;
     glm::vec4 tint {1.0f};
-    
     const Texture* currentTexture;
+    UVRegion region {0.0f, 0.0f, 1.0f, 1.0f};
 
     void vertex(
         float x, float y, float z,
@@ -102,6 +103,8 @@ public:
         const glm::vec4& tint,
         bool shading = true
     );
+    void setRegion(UVRegion region);
+    void vertex(const glm::vec3& pos, const glm::vec2& uv, const glm::vec3& norm);
     void vertex(const glm::vec3& pos, const glm::vec2& uv, const glm::vec4& tint);
     void point(const glm::vec3& pos, const glm::vec4& tint);
     void flush() override;
diff --git a/src/graphics/core/DrawContext.hpp b/src/graphics/core/DrawContext.hpp
index 7e1e18d5..d9c61c19 100644
--- a/src/graphics/core/DrawContext.hpp
+++ b/src/graphics/core/DrawContext.hpp
@@ -34,7 +34,7 @@ public:
     Batch2D* getBatch2D() const;
     
     const glm::uvec2& getViewport() const;
-    DrawContext sub(Flushable* flushable=nullptr) const;
+    [[nodiscard]] DrawContext sub(Flushable* flushable=nullptr) const;
 
     void setViewport(const glm::uvec2& viewport);
     void setFramebuffer(Framebuffer* fbo);
diff --git a/src/graphics/core/Shader.cpp b/src/graphics/core/Shader.cpp
index 122495ff..626d747b 100644
--- a/src/graphics/core/Shader.cpp
+++ b/src/graphics/core/Shader.cpp
@@ -16,6 +16,7 @@
 namespace fs = std::filesystem;
 
 GLSLExtension* Shader::preprocessor = new GLSLExtension();
+Shader* Shader::used = nullptr;
 
 Shader::Shader(uint id) : id(id){
 }
@@ -25,6 +26,7 @@ Shader::~Shader(){
 }
 
 void Shader::use(){
+    used = this;
     glUseProgram(id);
 }
 
@@ -131,3 +133,7 @@ std::unique_ptr<Shader> Shader::create(
     }
     return std::make_unique<Shader>(id);
 }
+
+Shader& Shader::getUsed() {
+    return *used;
+}
diff --git a/src/graphics/core/Shader.hpp b/src/graphics/core/Shader.hpp
index 5c970d4f..18a14da7 100644
--- a/src/graphics/core/Shader.hpp
+++ b/src/graphics/core/Shader.hpp
@@ -10,6 +10,7 @@
 class GLSLExtension;
 
 class Shader {
+    static Shader* used;
     uint id;
     std::unordered_map<std::string, uint> uniformLocations;
     
@@ -43,4 +44,6 @@ public:
         const std::string& vertexSource, 
         const std::string& fragmentSource
     );
+
+    static Shader& getUsed();
 };
diff --git a/src/graphics/render/ModelsGenerator.cpp b/src/graphics/render/ModelsGenerator.cpp
index acd6366f..230c4804 100644
--- a/src/graphics/render/ModelsGenerator.cpp
+++ b/src/graphics/render/ModelsGenerator.cpp
@@ -50,16 +50,31 @@ static inline UVRegion get_region_for(
 
 void ModelsGenerator::prepare(Content& content, Assets& assets) {
     for (auto& [name, def] : content.blocks.getDefs()) {
-        if (def->model.type == BlockModelType::CUSTOM && def->model.name.empty()) {
-            assets.store(
-                std::make_unique<model::Model>(
-                    loadCustomBlockModel(
-                        def->model.customRaw, assets, !def->shadeless
-                    )
-                ),
-                name + ".model"
-            );
-            def->model.name = def->name + ".model";
+        if (def->model.type == BlockModelType::CUSTOM) {
+            if (def->model.name.empty()) {
+                assets.store(
+                    std::make_unique<model::Model>(
+                        loadCustomBlockModel(
+                            def->model.customRaw, assets, !def->shadeless
+                        )
+                    ),
+                    name + ".model"
+                );
+                def->model.name = def->name + ".model";
+            } else {
+                auto srcModel = assets.get<model::Model>(def->model.name);
+                if (srcModel) {
+                    auto model = std::make_unique<model::Model>(*srcModel);
+                    for (auto& mesh : model->meshes) {
+                        if (mesh.texture.length() && mesh.texture[0] == '$') {
+                            int index = std::stoll(mesh.texture.substr(1));
+                            mesh.texture = "blocks:" + def->textureFaces[index];
+                        }
+                    }
+                    def->model.name = name + ".model";
+                    assets.store(std::move(model), def->model.name);
+                }
+            }
         }
     }
     for (auto& [name, def] : content.items.getDefs()) {
@@ -83,7 +98,7 @@ model::Model ModelsGenerator::fromCustom(
     for (size_t i = 0; i < modelBoxes.size(); i++) {
         auto& mesh = model.addMesh("blocks:");
         mesh.lighting = lighting;
-        const UVRegion boxtexfaces[6] = {
+        UVRegion boxtexfaces[6] = {
             get_region_for(modelTextures[i * 6 + 5], assets),
             get_region_for(modelTextures[i * 6 + 4], assets),
             get_region_for(modelTextures[i * 6 + 3], assets),
@@ -91,8 +106,15 @@ model::Model ModelsGenerator::fromCustom(
             get_region_for(modelTextures[i * 6 + 1], assets),
             get_region_for(modelTextures[i * 6 + 0], assets)
         };
+        boxtexfaces[2].scale(glm::vec2(-1));
+        boxtexfaces[5].scale(glm::vec2(-1, 1));
+
+        bool enabled[6] {1,1,1,1,1,1};
         mesh.addBox(
-            modelBoxes[i].center(), modelBoxes[i].size() * 0.5f, boxtexfaces
+            modelBoxes[i].center(),
+            modelBoxes[i].size() * 0.5f,
+            boxtexfaces,
+            enabled
         );
     }
     for (size_t i = 0; i < points.size() / 4; i++) {
diff --git a/src/graphics/ui/elements/InlineFrame.cpp b/src/graphics/ui/elements/InlineFrame.cpp
index cd01d45b..13625058 100644
--- a/src/graphics/ui/elements/InlineFrame.cpp
+++ b/src/graphics/ui/elements/InlineFrame.cpp
@@ -36,6 +36,7 @@ void InlineFrame::setDocument(const std::shared_ptr<UiDocument>& document) {
 }
 
 void InlineFrame::act(float delta) {
+    Container::act(delta);
     if (document || src.empty()) {
         return;
     }
diff --git a/src/graphics/ui/elements/ModelViewer.cpp b/src/graphics/ui/elements/ModelViewer.cpp
new file mode 100644
index 00000000..acc8170c
--- /dev/null
+++ b/src/graphics/ui/elements/ModelViewer.cpp
@@ -0,0 +1,152 @@
+#include <array>
+#include <glm/ext.hpp>
+#include "ModelViewer.hpp"
+
+#include "assets/Assets.hpp"
+#include "assets/assets_util.hpp"
+#include "graphics/commons/Model.hpp"
+#include "graphics/core/Batch2D.hpp"
+#include "graphics/core/Batch3D.hpp"
+#include "graphics/core/Shader.hpp"
+#include "graphics/core/Framebuffer.hpp"
+#include "graphics/core/DrawContext.hpp"
+#include "window/Window.hpp"
+#include "../GUI.hpp"
+
+// TODO: remove
+#include <GL/glew.h>
+
+using namespace gui;
+
+ModelViewer::ModelViewer(
+    GUI& gui, const glm::vec2& size, const std::string& modelName
+)
+    : Container(gui, size),
+      modelName(modelName),
+      camera(),
+      batch(std::make_unique<Batch3D>(1024)),
+      fbo(std::make_unique<Framebuffer>(size.x, size.y)) {
+    camera.perspective = true;
+    camera.position = glm::vec3(2, 2, 2);
+}
+
+ModelViewer::~ModelViewer() = default;
+
+void ModelViewer::setModel(const std::string& modelName) {
+    this->modelName = modelName;
+}
+
+const std::string& ModelViewer::getModel() const {
+    return modelName;
+}
+
+Camera& ModelViewer::getCamera() {
+    return camera;
+}
+
+const Camera& ModelViewer::getCamera() const {
+    return camera;
+}
+
+void ModelViewer::act(float delta) {
+    Container::act(delta);
+
+    auto& input = gui.getInput();
+    
+    if (!grabbing && hover && input.jclicked(Mousecode::BUTTON_3)) {
+        grabbing = true;
+    }
+    if (grabbing && input.clicked(Mousecode::BUTTON_3)) {
+        auto cursor = input.getCursor();
+        if (input.pressed(Keycode::LEFT_SHIFT)) {
+            center -= camera.right * (cursor.delta.x / size.x) * distance;
+            center += camera.up * (cursor.delta.y / size.y) * distance;
+        } else {
+            rotation.x -= cursor.delta.x / size.x * glm::two_pi<float>();
+            rotation.y -= cursor.delta.y / size.y * glm::two_pi<float>();
+            rotation.y = glm::max(
+                -glm::half_pi<float>(), glm::min(glm::half_pi<float>(), rotation.y)
+            );
+        }
+    } else if (grabbing) {
+        grabbing = false;
+    }
+    if (hover) {
+        distance *= 1.0f - 0.2f * input.getScroll();
+    }
+    camera.rotation = glm::mat4(1.0f);
+    camera.rotate(rotation.y, rotation.x, rotation.z);
+    camera.position = center - camera.front * distance;
+}
+
+void ModelViewer::draw(const DrawContext& pctx, const Assets& assets) {
+    camera.setAspectRatio(size.x / size.y);
+    camera.updateVectors();
+    
+    auto model = assets.get<model::Model>(modelName);
+    if (model == nullptr) {
+        return;
+    }
+    auto& prevShader = Shader::getUsed();
+    
+    fbo->resize(size.x, size.y);
+    {
+        glDisable(GL_SCISSOR_TEST);
+        auto ctx = pctx.sub();
+        ctx.setFramebuffer(fbo.get());
+        ctx.setViewport({size.x, size.y});
+        ctx.setDepthTest(true);
+        ctx.setCullFace(true);
+        display::clear();
+        
+        auto& ui3dShader = assets.require<Shader>("ui3d");
+        ui3dShader.use();
+        ui3dShader.uniformMatrix("u_apply", glm::mat4(1.0f));
+        ui3dShader.uniformMatrix("u_projview", camera.getProjView());
+        batch->begin();
+        for (const auto& mesh : model->meshes) {
+            util::TextureRegion region;
+            if (!mesh.texture.empty() && mesh.texture[0] == '$') {
+                // todo: refactor
+                static std::array<std::string, 6> faces {
+                    "blocks:dbg_north",
+                    "blocks:dbg_south",
+                    "blocks:dbg_top",
+                    "blocks:dbg_bottom",
+                    "blocks:dbg_west",
+                    "blocks:dbg_east",
+                };
+                region = util::get_texture_region(
+                    assets,
+                    faces.at(mesh.texture.at(1) - '0'),
+                    "blocks:notfound"
+                );
+            } else {
+                region = util::get_texture_region(assets, mesh.texture, "blocks:notfound");
+            }
+            batch->texture(region.texture);
+            batch->setRegion(region.region);
+            for (const auto& vertex : mesh.vertices) {
+                batch->vertex(vertex.coord, vertex.uv, vertex.normal);
+            }
+        }
+        batch->flush();
+        glEnable(GL_SCISSOR_TEST);
+    }
+
+    auto pos = calcPos();
+    prevShader.use();
+    auto& batch2d = *pctx.getBatch2D();
+    batch2d.texture(fbo->getTexture());
+    batch2d.rect(pos.x, pos.y, size.x, size.y, 0.0f, 0.0f, 0.0f, UVRegion {}, false, true, glm::vec4{1.0f});
+
+    Container::draw(pctx, assets);
+}
+
+void ModelViewer::setCenter(const glm::vec3& center) {
+    this->center = center;
+}
+
+void ModelViewer::setRotation(const glm::vec3& euler) {
+    this->rotation = euler;
+}
diff --git a/src/graphics/ui/elements/ModelViewer.hpp b/src/graphics/ui/elements/ModelViewer.hpp
new file mode 100644
index 00000000..37fa497e
--- /dev/null
+++ b/src/graphics/ui/elements/ModelViewer.hpp
@@ -0,0 +1,40 @@
+#pragma once
+
+#include <memory>
+#include <string>
+#include "Container.hpp"
+#include "window/Camera.hpp"
+
+class Batch3D;
+class Framebuffer;
+
+namespace gui {
+    class ModelViewer : public Container {
+    private:
+        std::string modelName;
+        Camera camera;
+        std::unique_ptr<Batch3D> batch;
+        std::unique_ptr<Framebuffer> fbo;
+
+        glm::vec3 rotation {};
+        glm::vec3 center {};
+        float distance = 4.0f;
+        bool grabbing = false;
+    public:
+        ModelViewer(GUI& gui, const glm::vec2& size, const std::string& modelName);
+
+        ~ModelViewer();
+
+        void setModel(const std::string& modelName);
+        const std::string& getModel() const;
+
+        Camera& getCamera();
+        const Camera& getCamera() const;
+
+        void act(float delta) override;
+        void draw(const DrawContext& pctx, const Assets& assets) override;
+
+        void setRotation(const glm::vec3& euler);
+        void setCenter(const glm::vec3& center);
+    };
+}
diff --git a/src/graphics/ui/elements/SplitBox.cpp b/src/graphics/ui/elements/SplitBox.cpp
index 8cbc94bf..c1fbcbcc 100644
--- a/src/graphics/ui/elements/SplitBox.cpp
+++ b/src/graphics/ui/elements/SplitBox.cpp
@@ -1,5 +1,7 @@
 #include "SplitBox.hpp"
 
+#include "util/stack_vector.hpp"
+
 using namespace gui;
 
 SplitBox::SplitBox(GUI& gui, const glm::vec2& size, float splitPos, Orientation orientation)
@@ -28,18 +30,31 @@ void SplitBox::mouseMove(int x, int y) {
 void SplitBox::refresh() {
     Container::refresh();
 
-    if (nodes.empty()) {
+    util::stack_vector<UINode*, 2> visibleNodes;
+
+    for (const auto& node : nodes) {
+        if (!node->isVisible()) {
+            continue;
+        }
+        visibleNodes.push_back(node.get());
+        if (visibleNodes.full()) {
+            break;
+        }
+    }
+
+    if (visibleNodes.empty()) {
         return;
     }
+
     glm::vec2 size = getSize();
-    if (nodes.size() == 1) {
-        auto node = nodes.at(0);
+    if (visibleNodes.size() == 1) {
+        auto node = visibleNodes.at(0);
         node->setPos(glm::vec2());
         node->setSize(size);
         return;
     }
-    auto nodeA = nodes.at(0);
-    auto nodeB = nodes.at(1);
+    auto nodeA = visibleNodes.at(0);
+    auto nodeB = visibleNodes.at(1);
 
     float sepRadius = interval / 2.0f;
     
diff --git a/src/graphics/ui/gui_xml.cpp b/src/graphics/ui/gui_xml.cpp
index d393dbae..fc9f86cb 100644
--- a/src/graphics/ui/gui_xml.cpp
+++ b/src/graphics/ui/gui_xml.cpp
@@ -19,6 +19,7 @@
 #include "elements/Panel.hpp"
 #include "elements/TextBox.hpp"
 #include "elements/TrackBar.hpp"
+#include "elements/ModelViewer.hpp"
 #include "engine/Engine.hpp"
 #include "frontend/locale.hpp"
 #include "frontend/menu.hpp"
@@ -368,6 +369,23 @@ static std::shared_ptr<UINode> read_split_box(
     return splitBox;
 }
 
+static std::shared_ptr<UINode> read_model_viewer(
+    UiXmlReader& reader, const xml::xmlelement& element
+) {
+    auto model = element.attr("src", "").getText();
+    auto viewer = std::make_shared<ModelViewer>(
+        reader.getGUI(), glm::vec2(), model
+    );
+    read_container_impl(reader, element, *viewer);
+    if (element.has("center")) {
+        viewer->setCenter(element.attr("center").asVec3());
+    }
+    if (element.has("cam-rotation")) {
+        viewer->setRotation(glm::radians(element.attr("cam-rotation").asVec3()));
+    }
+    return viewer;
+}
+
 static std::shared_ptr<UINode> read_panel(
     UiXmlReader& reader, const xml::xmlelement& element
 ) {
@@ -785,6 +803,7 @@ UiXmlReader::UiXmlReader(gui::GUI& gui, scriptenv&& env) : gui(gui), env(std::mo
     add("trackbar", read_track_bar);
     add("container", read_container);
     add("bindbox", read_input_bind_box);
+    add("modelviewer", read_model_viewer);
     add("inventory", read_inventory);
 }
 
diff --git a/src/io/engine_paths.cpp b/src/io/engine_paths.cpp
index cb2d11e9..39851228 100644
--- a/src/io/engine_paths.cpp
+++ b/src/io/engine_paths.cpp
@@ -192,6 +192,9 @@ std::string EnginePaths::createWriteableDevice(const std::string& name) {
             break;
         }
     }
+    if (name == "core") {
+        folder = "res:";
+    }
     if (folder.emptyOrInvalid()) {
         throw std::runtime_error("pack not found");
     }
diff --git a/src/logic/scripting/lua/libs/api_lua.hpp b/src/logic/scripting/lua/libs/api_lua.hpp
index 7b4253c5..6e65b790 100644
--- a/src/logic/scripting/lua/libs/api_lua.hpp
+++ b/src/logic/scripting/lua/libs/api_lua.hpp
@@ -15,6 +15,7 @@
 
 // Libraries
 extern const luaL_Reg applib[];
+extern const luaL_Reg assetslib[];
 extern const luaL_Reg audiolib[];
 extern const luaL_Reg base64lib[];
 extern const luaL_Reg bjsonlib[];
diff --git a/src/logic/scripting/lua/libs/libassets.cpp b/src/logic/scripting/lua/libs/libassets.cpp
new file mode 100644
index 00000000..8cfb8ca8
--- /dev/null
+++ b/src/logic/scripting/lua/libs/libassets.cpp
@@ -0,0 +1,66 @@
+#include "api_lua.hpp"
+
+#include "assets/Assets.hpp"
+#include "coders/png.hpp"
+#include "coders/vcm.hpp"
+#include "debug/Logger.hpp"
+#include "engine/Engine.hpp"
+#include "graphics/commons/Model.hpp"
+#include "graphics/core/Texture.hpp"
+#include "util/Buffer.hpp"
+
+using namespace scripting;
+
+static void load_texture(
+    const ubyte* bytes, size_t size, const std::string& destname
+) {
+    try {
+        engine->getAssets()->store(png::load_texture(bytes, size), destname);
+    } catch (const std::runtime_error& err) {
+        debug::Logger logger("lua.assetslib");
+        logger.error() << err.what();
+    }
+}
+
+static int l_load_texture(lua::State* L) {
+    if (lua::istable(L, 1)) {
+        lua::pushvalue(L, 1);
+        size_t size = lua::objlen(L, 1);
+        util::Buffer<ubyte> buffer(size);
+        for (size_t i = 0; i < size; i++) {
+            lua::rawgeti(L, i + 1);
+            buffer[i] = lua::tointeger(L, -1);
+            lua::pop(L);
+        }
+        lua::pop(L);
+        load_texture(buffer.data(), buffer.size(), lua::require_string(L, 2));
+    } else {
+        auto string = lua::bytearray_as_string(L, 1);
+        load_texture(
+            reinterpret_cast<const ubyte*>(string.data()),
+            string.size(),
+            lua::require_string(L, 2)
+        );
+        lua::pop(L);
+    }
+    return 0;
+}
+
+static int l_parse_model(lua::State* L) {
+    auto format = lua::require_lstring(L, 1);
+    auto string = lua::require_lstring(L, 2);
+    auto name = lua::require_string(L, 3);
+    
+    if (format == "xml" || format == "vcm") {
+        engine->getAssets()->store(vcm::parse(name, string), name);
+    } else {
+        throw std::runtime_error("unknown format " + util::quote(std::string(format)));
+    }
+    return 0;
+}
+
+const luaL_Reg assetslib[] = {
+    {"load_texture", lua::wrap<l_load_texture>},
+    {"parse_model", lua::wrap<l_parse_model>},
+    {NULL, NULL}
+};
diff --git a/src/logic/scripting/lua/libs/libcore.cpp b/src/logic/scripting/lua/libs/libcore.cpp
index 7ebdbc38..c453927c 100644
--- a/src/logic/scripting/lua/libs/libcore.cpp
+++ b/src/logic/scripting/lua/libs/libcore.cpp
@@ -1,13 +1,12 @@
 #include <memory>
 #include <vector>
+#include <sstream>
 
 #include "api_lua.hpp"
-#include "coders/png.hpp"
 #include "constants.hpp"
 #include "assets/Assets.hpp"
 #include "content/Content.hpp"
 #include "content/ContentControl.hpp"
-#include "debug/Logger.hpp"
 #include "engine/Engine.hpp"
 #include "io/engine_paths.hpp"
 #include "io/io.hpp"
@@ -225,41 +224,6 @@ static int l_get_setting_info(lua::State* L) {
     throw std::runtime_error("unsupported setting type");
 }
 
-static void load_texture(
-    const ubyte* bytes, size_t size, const std::string& destname
-) {
-    try {
-        engine->getAssets()->store(png::load_texture(bytes, size), destname);
-    } catch (const std::runtime_error& err) {
-        debug::Logger logger("lua.corelib");
-        logger.error() << err.what();
-    }
-}
-
-static int l_load_texture(lua::State* L) {
-    if (lua::istable(L, 1)) {
-        lua::pushvalue(L, 1);
-        size_t size = lua::objlen(L, 1);
-        util::Buffer<ubyte> buffer(size);
-        for (size_t i = 0; i < size; i++) {
-            lua::rawgeti(L, i + 1);
-            buffer[i] = lua::tointeger(L, -1);
-            lua::pop(L);
-        }
-        lua::pop(L);
-        load_texture(buffer.data(), buffer.size(), lua::require_string(L, 2));
-    } else {
-        auto string = lua::bytearray_as_string(L, 1);
-        load_texture(
-            reinterpret_cast<const ubyte*>(string.data()),
-            string.size(),
-            lua::require_string(L, 2)
-        );
-        lua::pop(L);
-    }
-    return 0;
-}
-
 static int l_open_folder(lua::State* L) {
     platform::open_folder(io::resolve(lua::require_string(L, 1)));
     return 0;
@@ -322,6 +286,5 @@ const luaL_Reg corelib[] = {
     {"open_folder", lua::wrap<l_open_folder>},
     {"quit", lua::wrap<l_quit>},
     {"capture_output", lua::wrap<l_capture_output>},
-    {"__load_texture", lua::wrap<l_load_texture>},
     {NULL, NULL}
 };
diff --git a/src/logic/scripting/lua/libs/libgui.cpp b/src/logic/scripting/lua/libs/libgui.cpp
index af317f94..8a1f12db 100644
--- a/src/logic/scripting/lua/libs/libgui.cpp
+++ b/src/logic/scripting/lua/libs/libgui.cpp
@@ -14,6 +14,7 @@
 #include "graphics/ui/elements/TextBox.hpp"
 #include "graphics/ui/elements/TrackBar.hpp"
 #include "graphics/ui/elements/InlineFrame.hpp"
+#include "graphics/ui/elements/ModelViewer.hpp"
 #include "graphics/ui/gui_util.hpp"
 #include "graphics/ui/markdown.hpp"
 #include "graphics/core/Font.hpp"
@@ -114,6 +115,16 @@ static int l_node_destruct(lua::State* L) {
     return 0;
 }
 
+static int l_container_refresh(lua::State* L) {
+    auto docnode = get_document_node(L);
+    auto node = dynamic_cast<Container*>(docnode.node.get());
+    if (node == nullptr) {
+        return 0;
+    }
+    node->refresh();
+    return 0;
+}
+
 static int l_node_reposition(lua::State* L) {
     auto docnode = get_document_node(L);
     docnode.node->reposition();
@@ -341,6 +352,8 @@ static int p_get_src(UINode* node, lua::State* L) {
         return lua::pushstring(L, image->getTexture());
     } else if (auto iframe = dynamic_cast<InlineFrame*>(node)) {
         return lua::pushstring(L, iframe->getSrc());
+    } else if (auto modelviewer = dynamic_cast<ModelViewer*>(node)) {
+        return lua::pushstring(L, modelviewer->getModel());
     }
     return 0;
 }
@@ -408,6 +421,13 @@ static int p_get_destruct(UINode*, lua::State* L) {
     return lua::pushcfunction(L, lua::wrap<l_node_destruct>);
 }
 
+static int p_refresh(UINode* node, lua::State* L) {
+    if (dynamic_cast<Container*>(node)) {
+        return lua::pushcfunction(L, lua::wrap<l_container_refresh>);
+    }
+    return 0;
+}
+
 static int p_get_reposition(UINode*, lua::State* L) {
     return lua::pushcfunction(L, lua::wrap<l_node_reposition>);
 }
@@ -490,6 +510,12 @@ static int p_get_scroll(UINode* node, lua::State* L) {
 }
 
 static int l_gui_getattr(lua::State* L) {
+    if (!lua::isstring(L, 1)) {
+        throw std::runtime_error("document name is not a string");
+    }
+    if (!lua::isstring(L, 2)) {
+        throw std::runtime_error("element id is not a string");
+    }
     auto docname = lua::require_string(L, 1);
     auto element = lua::require_string(L, 2);
     if (lua::isnumber(L, 3)) {
@@ -507,6 +533,9 @@ static int l_gui_getattr(lua::State* L) {
         const auto& id = request_node_id(DocumentNode {docnode.document, node});
         return push_document_node(L, id);
     }
+    if (!lua::isstring(L, 3)) {
+        throw std::runtime_error("attribute name is not a string");
+    }
     auto attr = lua::require_string(L, 3);
 
     static const std::unordered_map<
@@ -530,6 +559,7 @@ static int l_gui_getattr(lua::State* L) {
             {"moveInto", p_move_into},
             {"add", p_get_add},
             {"destruct", p_get_destruct},
+            {"refresh", p_refresh},
             {"reposition", p_get_reposition},
             {"clear", p_get_clear},
             {"setInterval", p_set_interval},
@@ -666,6 +696,8 @@ static void p_set_src(UINode* node, lua::State* L, int idx) {
         image->setTexture(lua::require_string(L, idx));
     } else if (auto iframe = dynamic_cast<InlineFrame*>(node)) {
         iframe->setSrc(lua::require_string(L, idx));
+    } else if (auto modelviewer = dynamic_cast<ModelViewer*>(node)) {
+        modelviewer->setModel(lua::require_string(L, idx));
     }
 }
 static void p_set_region(UINode* node, lua::State* L, int idx) {
@@ -755,6 +787,15 @@ static int p_set_scroll(UINode* node, lua::State* L, int idx) {
 }
 
 static int l_gui_setattr(lua::State* L) {
+    if (!lua::isstring(L, 1)) {
+        throw std::runtime_error("document name is not a string");
+    }
+    if (!lua::isstring(L, 2)) {
+        throw std::runtime_error("element id is not a string");
+    }
+    if (!lua::isstring(L, 3)) {
+        throw std::runtime_error("attribute name is not a string");
+    }
     auto docname = lua::require_string(L, 1);
     auto element = lua::require_string(L, 2);
     auto attr = lua::require_string(L, 3);
diff --git a/src/logic/scripting/lua/lua_engine.cpp b/src/logic/scripting/lua/lua_engine.cpp
index ca335c49..891b89c7 100644
--- a/src/logic/scripting/lua/lua_engine.cpp
+++ b/src/logic/scripting/lua/lua_engine.cpp
@@ -64,6 +64,7 @@ static void create_libs(State* L, StateType stateType) {
         openlib(L, "__vc_app", applib);
     }
     if (stateType == StateType::BASE || stateType == StateType::SCRIPT) {
+        openlib(L, "assets", assetslib);
         openlib(L, "audio", audiolib);
         openlib(L, "console", consolelib);
         openlib(L, "core", corelib);
diff --git a/src/maths/UVRegion.hpp b/src/maths/UVRegion.hpp
index 019c8760..354c939b 100644
--- a/src/maths/UVRegion.hpp
+++ b/src/maths/UVRegion.hpp
@@ -2,6 +2,7 @@
 
 #include <cmath>
 #include <glm/vec2.hpp>
+#include <glm/vec4.hpp>
 
 struct UVRegion {
     float u1;
@@ -42,8 +43,8 @@ struct UVRegion {
     }
 
     void scale(float x, float y) {
-        float w = getWidth();
-        float h = getHeight();
+        float w = u2 - u1;
+        float h = v2 - v1;
         float cx = (u1 + u2) * 0.5f;
         float cy = (v1 + v2) * 0.5f;
         u1 = cx - w * 0.5f * x;
@@ -51,4 +52,21 @@ struct UVRegion {
         u2 = cx + w * 0.5f * x;
         v2 = cy + h * 0.5f * y;
     }
+
+    void scale(const glm::vec2& vec) {
+        scale(vec.x, vec.y);
+    }
+
+    void set(const glm::vec4& vec) {
+        u1 = vec.x;
+        v1 = vec.y;
+        u2 = vec.z;
+        v2 = vec.w;
+    }
+
+    UVRegion operator*(const glm::vec2& scale) const {
+        auto copy = UVRegion(*this);
+        copy.scale(scale);
+        return copy;
+    }
 };
diff --git a/src/util/stack_vector.hpp b/src/util/stack_vector.hpp
new file mode 100644
index 00000000..e73bbb11
--- /dev/null
+++ b/src/util/stack_vector.hpp
@@ -0,0 +1,99 @@
+#pragma once
+
+namespace util {
+    template<typename T, int capacity>
+    class stack_vector {
+    public:
+        stack_vector() : size_(0) {}
+
+        stack_vector(const stack_vector<T, capacity>& other)
+            : size_(other.size_) {
+            for (int i = 0; i < size_; ++i) {
+                new (&data_[i]) T(data_[i]);
+            }
+        }
+
+        stack_vector(stack_vector<T, capacity>&& other) noexcept
+            : size_(other.size_) {
+            for (int i = 0; i < size_; ++i) {
+                new (&data_[i]) T(std::move(other.data_[i]));
+            }
+            other.size_ = 0;
+        }
+
+        stack_vector(const std::initializer_list<T>& init) : size_(0) {
+            static_assert(
+                init.size() <= capacity,
+                "initializer list exceeds stack vector capacity"
+            );
+            for (const auto& value : init) {
+                new (&data_[size_++]) T(value);
+            }
+        }
+
+        ~stack_vector() {
+            clear();
+        }
+
+        void push_back(const T& value) {
+            if (size_ < capacity) {
+                data_[size_++] = value;
+            } else {
+                throw std::overflow_error("stack vector capacity exceeded");
+            }
+        }
+
+        void pop_back() {
+            if (size_ > 0) {
+                data_[size_ - 1].~T();
+                --size_;
+            } else {
+                throw std::underflow_error("stack vector is empty");
+            }
+        }
+
+        void clear() {
+            for (int i = 0; i < size_; ++i) {
+                data_[i].~T();
+            }
+            size_ = 0;
+        }
+
+        T& operator[](int index) {
+            return data_[index];
+        }
+        
+        const T& operator[](int index) const {
+            return data_[index];
+        }
+
+        T& at(int index) {
+            if (index < 0 || index >= size_) {
+                throw std::out_of_range("index out of range");
+            }
+            return data_[index];
+        }
+
+        const T& at(int index) const {
+            if (index < 0 || index >= size_) {
+                throw std::out_of_range("index out of range");
+            }
+            return data_[index];
+        }
+
+        int size() const { 
+            return size_;
+        }
+
+        bool empty() const {
+            return size_ == 0;
+        }
+
+        bool full() const {
+            return size_ == capacity;
+        }
+    private:
+        T data_[capacity];
+        int size_;
+    };
+}
diff --git a/test/coders/xml.cpp b/test/coders/xml.cpp
new file mode 100644
index 00000000..1357a449
--- /dev/null
+++ b/test/coders/xml.cpp
@@ -0,0 +1,24 @@
+#include <gtest/gtest.h>
+
+#include "coders/xml.hpp"
+#include "coders/commons.hpp"
+
+TEST(XML, VCM) {
+    std::string code = ""
+        "@line x1 y1 z1\n"
+        "# @tst ysfdrg\n"
+        "@box {\n"
+        "  @rect texture \"$2\"\n"
+        "  @utro a 53.1\n"
+        "}\n"
+    ;
+    std::cout << code << std::endl;
+
+    try {
+        auto document = xml::parse_vcm("<test>", code, "test");
+        std::cout << xml::stringify(*document);
+    } catch (const parsing_error& err) {
+        std::cerr << err.errorLog() << std::endl;
+        throw err;
+    }
+}