diff --git a/res/content/base/generators/demo.files/fragments/tower.vox b/res/content/base/generators/demo.files/fragments/tower.vox
index c992fe45..a6b58857 100644
Binary files a/res/content/base/generators/demo.files/fragments/tower.vox and b/res/content/base/generators/demo.files/fragments/tower.vox differ
diff --git a/res/content/base/generators/demo.files/fragments/tree0.vox b/res/content/base/generators/demo.files/fragments/tree0.vox
index 74cbcc3f..78e87cbf 100644
Binary files a/res/content/base/generators/demo.files/fragments/tree0.vox and b/res/content/base/generators/demo.files/fragments/tree0.vox differ
diff --git a/res/content/base/generators/demo.files/fragments/tree1.vox b/res/content/base/generators/demo.files/fragments/tree1.vox
index 7dda751d..6c2aec44 100644
Binary files a/res/content/base/generators/demo.files/fragments/tree1.vox and b/res/content/base/generators/demo.files/fragments/tree1.vox differ
diff --git a/res/content/base/generators/demo.files/fragments/tree2.vox b/res/content/base/generators/demo.files/fragments/tree2.vox
index 98fc3bef..0aac534c 100644
Binary files a/res/content/base/generators/demo.files/fragments/tree2.vox and b/res/content/base/generators/demo.files/fragments/tree2.vox differ
diff --git a/res/scripts/stdcmd.lua b/res/scripts/stdcmd.lua
index ef742d5e..a2edd9b8 100644
--- a/res/scripts/stdcmd.lua
+++ b/res/scripts/stdcmd.lua
@@ -174,3 +174,16 @@ console.add_command(
                     " has been saved as "..file.resolve(filename))
     end
 )
+
+console.add_command(
+    "fragment.crop filename:str",
+    "Crop fragment",
+    function(args, kwargs)
+        local filename = args[1]
+        local fragment = generation.load_fragment(filename)
+        fragment:crop()
+        generation.save_fragment(fragment, filename, crop)
+        console.log("fragment with size "..vec3.tostring(fragment.size)..
+                    " has been saved as "..file.resolve(filename))
+    end
+)
diff --git a/src/content/loading/GeneratorLoader.cpp b/src/content/loading/GeneratorLoader.cpp
index 54b9b288..ec8315f5 100644
--- a/src/content/loading/GeneratorLoader.cpp
+++ b/src/content/loading/GeneratorLoader.cpp
@@ -145,6 +145,9 @@ static std::vector<std::unique_ptr<VoxelStructure>> load_structures(
         }
         auto fragment = std::make_unique<VoxelFragment>();
         fragment->deserialize(files::read_binary_json(structFile));
+        logger.info() << "fragment " << name << " has size [" << 
+            fragment->getSize().x << ", " << fragment->getSize().y << ", " <<
+            fragment->getSize().z << "]";
 
         structures.push_back(std::make_unique<VoxelStructure>(
             load_structure_meta(name, config),
diff --git a/src/logic/scripting/lua/libs/libgeneration.cpp b/src/logic/scripting/lua/libs/libgeneration.cpp
index 2874dbad..ca97815c 100644
--- a/src/logic/scripting/lua/libs/libgeneration.cpp
+++ b/src/logic/scripting/lua/libs/libgeneration.cpp
@@ -36,9 +36,8 @@ static int l_create_fragment(lua::State* L) {
 
 static int l_load_fragment(lua::State* L) {
     auto paths = engine->getPaths();
-    auto [prefix, filename] = EnginePaths::parsePath(lua::require_string(L, 1));
-
-    auto path = paths->resolve(prefix+":generators/"+filename+".vox");
+    auto filename = lua::require_string(L, 1);
+    auto path = paths->resolve(filename);
     if (!std::filesystem::exists(path)) {
         throw std::runtime_error("file "+path.u8string()+" does not exist");
     }
diff --git a/src/logic/scripting/lua/usertypes/lua_type_voxelstructure.cpp b/src/logic/scripting/lua/usertypes/lua_type_voxelstructure.cpp
index fd40ee83..eb6a24ab 100644
--- a/src/logic/scripting/lua/usertypes/lua_type_voxelstructure.cpp
+++ b/src/logic/scripting/lua/usertypes/lua_type_voxelstructure.cpp
@@ -13,6 +13,17 @@ LuaVoxelFragment::LuaVoxelFragment(std::shared_ptr<VoxelFragment> fragment)
 LuaVoxelFragment::~LuaVoxelFragment() {
 }
 
+static int l_crop(lua::State* L) {
+    if (auto fragment = touserdata<LuaVoxelFragment>(L, 1)) {
+        fragment->getFragment()->crop();
+    }
+    return 0;
+}
+
+static std::unordered_map<std::string, lua_CFunction> methods {
+    {"crop", lua::wrap<l_crop>},
+};
+
 static int l_meta_tostring(lua::State* L) {
     return pushstring(L, "VoxelFragment(0x" + util::tohex(
         reinterpret_cast<uint64_t>(topointer(L, 1)))+")");
@@ -27,12 +38,16 @@ static int l_meta_index(lua::State* L) {
         auto fieldname = tostring(L, 2);
         if (!std::strcmp(fieldname, "size")) {
             return pushivec(L, fragment->getFragment()->getSize());
+        } else {
+            auto found = methods.find(tostring(L, 2));
+            if (found != methods.end()) {
+                return pushcfunction(L, found->second);
+            }
         }
     }
     return 0;
 }
 
-
 int LuaVoxelFragment::createMetatable(lua::State* L) {
     createtable(L, 0, 2);
     pushcfunction(L, lua::wrap<l_meta_tostring>);
diff --git a/src/voxels/ChunksStorage.cpp b/src/voxels/ChunksStorage.cpp
index 75925a38..75b37b9e 100644
--- a/src/voxels/ChunksStorage.cpp
+++ b/src/voxels/ChunksStorage.cpp
@@ -108,10 +108,10 @@ void ChunksStorage::getVoxels(VoxelsVolume* volume, bool backlight) const {
     int ecz = floordiv(z + d, CHUNK_D);
 
     int cw = ecx - scx + 1;
-    int ch = ecz - scz + 1;
+    int cd = ecz - scz + 1;
 
-    // cw*ch chunks will be scanned
-    for (int cz = scz; cz < scz + ch; cz++) {
+    // cw*cd chunks will be scanned
+    for (int cz = scz; cz < scz + cd; cz++) {
         for (int cx = scx; cx < scx + cw; cx++) {
             const auto& found = chunksMap.find(glm::ivec2(cx, cz));
             if (found == chunksMap.end()) {
diff --git a/src/world/generator/VoxelFragment.cpp b/src/world/generator/VoxelFragment.cpp
index 5289051b..96191725 100644
--- a/src/world/generator/VoxelFragment.cpp
+++ b/src/world/generator/VoxelFragment.cpp
@@ -9,6 +9,7 @@
 #include "voxels/ChunksStorage.hpp"
 #include "voxels/VoxelsVolume.hpp"
 #include "world/Level.hpp"
+#include "core_defs.hpp"
 
 std::unique_ptr<VoxelFragment> VoxelFragment::create(
     Level* level,
@@ -51,10 +52,10 @@ std::unique_ptr<VoxelFragment> VoxelFragment::create(
     level->chunksStorage->getVoxels(&volume);
 
     auto volVoxels = volume.getVoxels();
-    std::vector<voxel> voxels(size.x*size.y*size.z);
+    std::vector<voxel> voxels(size.x * size.y * size.z);
 
-    std::vector<std::string> blockNames;
-    std::unordered_map<blockid_t, blockid_t> blocksRegistered;
+    std::vector<std::string> blockNames {CORE_AIR};
+    std::unordered_map<blockid_t, blockid_t> blocksRegistered {{0, 0}};
     auto contentIndices = level->content->getIndices();
     for (size_t i = 0 ; i < voxels.size(); i++) {
         blockid_t id = volVoxels[i].id;
@@ -113,6 +114,49 @@ void VoxelFragment::deserialize(const dv::value& src) {
     }
 }
 
+void VoxelFragment::crop() {
+    glm::ivec3 min = size;
+    glm::ivec3 max = {};
+    
+    blockid_t air;
+    const auto& found = std::find(blockNames.begin(), blockNames.end(), CORE_AIR);
+    if (found == blockNames.end()) {
+        throw std::runtime_error(CORE_AIR+" is not found in fragment");
+    }
+    air = found - blockNames.begin();
+
+    for (int y = 0; y < size.y; y++) {
+        for (int z = 0; z < size.z; z++) {
+            for (int x = 0; x < size.x; x++) {
+                if (voxels[vox_index(x, y, z, size.x, size.z)].id != air) {
+                    min = glm::min(min, {x, y, z});
+                    max = glm::max(max, {x+1, y+1, z+1});
+                }
+            }
+        }
+    }
+    if (glm::min(min, max) == min) {
+        auto newSize = max - min;
+        std::vector<voxel> newVoxels(newSize.x * newSize.y * newSize.z);
+        for (int y = 0; y < newSize.y; y++) {
+            for (int z = 0; z < newSize.z; z++) {
+                for (int x = 0; x < newSize.x; x++) {
+                    newVoxels[vox_index(x, y, z, newSize.x, newSize.z)] =
+                        voxels[vox_index(
+                            x + min.x,
+                            y + min.y,
+                            z + min.z,
+                            size.x,
+                            size.z
+                        )];
+                }
+            }
+        }
+        voxels = std::move(newVoxels);
+        size = newSize;
+    }
+}
+
 void VoxelFragment::prepare(const Content& content) {
     auto volume = size.x*size.y*size.z;
     voxelsRuntime.resize(volume);
@@ -129,8 +173,8 @@ std::unique_ptr<VoxelFragment> VoxelFragment::rotated(const Content& content) co
     for (int y = 0; y < size.y; y++) {
         for (int z = 0; z < size.z; z++) {
             for (int x = 0; x < size.x; x++) {
-                auto& voxel = newVoxels[vox_index(x, y, z, size.x, size.z)];
-                voxel = voxels[vox_index(size.z-z-1, y, x, size.z, size.x)];
+                auto& voxel = newVoxels[vox_index(size.z-z-1, y, x, size.z, size.x)];
+                voxel = voxels[vox_index(x, y, z, size.x, size.z)];
                 // swap X and Z segment bits
                 voxel.state.segment = ((voxel.state.segment & 0b001) << 2)
                                     | (voxel.state.segment & 0b010)
diff --git a/src/world/generator/VoxelFragment.hpp b/src/world/generator/VoxelFragment.hpp
index f9e94ab8..95a5375b 100644
--- a/src/world/generator/VoxelFragment.hpp
+++ b/src/world/generator/VoxelFragment.hpp
@@ -35,6 +35,7 @@ public:
 
     dv::value serialize() const override;
     void deserialize(const dv::value& src) override;
+    void crop();
 
     /// @brief Build runtime voxel indices
     /// @param content world content
diff --git a/src/world/generator/WorldGenerator.cpp b/src/world/generator/WorldGenerator.cpp
index 0f79c4e8..b0236ec2 100644
--- a/src/world/generator/WorldGenerator.cpp
+++ b/src/world/generator/WorldGenerator.cpp
@@ -272,9 +272,6 @@ void WorldGenerator::generateStructures(
             glm::ivec3 position {x, height, z};
             position.x -= structure.getSize().x / 2;
             position.z -= structure.getSize().z / 2;
-            prototype.placements.emplace_back(
-                1, StructurePlacement {structureId, position, rotation}
-            );
             placeStructure(
                 StructurePlacement {
                     structureId,
@@ -486,6 +483,7 @@ void WorldGenerator::generateStructure(
     auto& structVoxels = structure.getRuntimeVoxels();
     const auto& offset = placement.position;
     const auto& size = structure.getSize();
+
     for (int y = 0; y < size.y; y++) {
         int sy = y + offset.y;
         if (sy < 0 || sy >= CHUNK_H) {
diff --git a/src/world/generator/WorldGenerator.hpp b/src/world/generator/WorldGenerator.hpp
index c6f37fa1..fa8a51e0 100644
--- a/src/world/generator/WorldGenerator.hpp
+++ b/src/world/generator/WorldGenerator.hpp
@@ -66,10 +66,6 @@ class WorldGenerator {
 
     void generateStructures(ChunkPrototype& prototype, int x, int z);
 
-    void generatePlacements(
-        const ChunkPrototype& prototype, voxel* voxels, int x, int z
-    );
-
     void generateBiomes(ChunkPrototype& prototype, int x, int z);
 
     void generateHeightmap(ChunkPrototype& prototype, int x, int z);
@@ -81,6 +77,9 @@ class WorldGenerator {
 
     void placeLine(const LinePlacement& line, int priority);
 
+    void generatePlacements(
+        const ChunkPrototype& prototype, voxel* voxels, int x, int z
+    );
     void generateLine(
         const ChunkPrototype& prototype, 
         const LinePlacement& placement,
@@ -113,7 +112,8 @@ class WorldGenerator {
     void placeStructures(
         const std::vector<Placement>& placements,
         ChunkPrototype& prototype,
-        int x, int z);
+        int x, int z
+    );
 public:
     WorldGenerator(
         const GeneratorDef& def,