diff --git a/res/layouts/pages/settings_display.xml.lua b/res/layouts/pages/settings_display.xml.lua
index e861deb3..6e64a7d6 100644
--- a/res/layouts/pages/settings_display.xml.lua
+++ b/res/layouts/pages/settings_display.xml.lua
@@ -1,7 +1,8 @@
-function create_setting(id, name, step, postfix, tooltip)
+function create_setting(id, name, step, postfix, tooltip, changeonrelease)
     local info = core.get_setting_info(id)
     postfix = postfix or ""
     tooltip = tooltip or ""
+    changeonrelease = changeonrelease or ""
     document.root:add(gui.template("track_setting", {
         id=id,
         name=gui.str(name, "settings"),
@@ -10,13 +11,13 @@ function create_setting(id, name, step, postfix, tooltip)
         max=info.max,
         step=step,
         postfix=postfix,
-        tooltip=tooltip
+        tooltip=tooltip,
+        changeonrelease=changeonrelease
     }))
     update_setting(core.get_setting(id), id, name, postfix)
 end
 
 function update_setting(x, id, name, postfix)
-    core.set_setting(id, x)
     -- updating label
     document[id..".L"].text = string.format(
         "%s: %s%s", 
diff --git a/res/layouts/pages/settings_graphics.xml.lua b/res/layouts/pages/settings_graphics.xml.lua
index de00c87b..8a479a1c 100644
--- a/res/layouts/pages/settings_graphics.xml.lua
+++ b/res/layouts/pages/settings_graphics.xml.lua
@@ -1,7 +1,8 @@
-function create_setting(id, name, step, postfix, tooltip)
+function create_setting(id, name, step, postfix, tooltip, changeonrelease)
     local info = core.get_setting_info(id)
     postfix = postfix or ""
     tooltip = tooltip or ""
+    changeonrelease = changeonrelease or ""
     document.root:add(gui.template("track_setting", {
         id=id,
         name=gui.str(name, "settings"),
@@ -10,13 +11,13 @@ function create_setting(id, name, step, postfix, tooltip)
         max=info.max,
         step=step,
         postfix=postfix,
-        tooltip=tooltip
+        tooltip=tooltip,
+        changeonrelease=changeonrelease
     }))
     update_setting(core.get_setting(id), id, name, postfix)
 end
 
 function update_setting(x, id, name, postfix)
-    core.set_setting(id, x)
     -- updating label
     document[id..".L"].text = string.format(
         "%s: %s%s", 
diff --git a/res/layouts/templates/track_setting.xml b/res/layouts/templates/track_setting.xml
index 82ee81c1..519ba334 100644
--- a/res/layouts/templates/track_setting.xml
+++ b/res/layouts/templates/track_setting.xml
@@ -2,5 +2,6 @@
     <label id='%{id}.L' margin='0,3,0,0'>%{name}: %{value}%{postfix}</label>
     <trackbar 
         value='%{value}' min='%{min}' max='%{max}' step='%{step}' tooltip='%{tooltip}'
-        consumer='function(x) update_setting(x, "%{id}", "%{name}", "%{postfix}") end'/>
+        consumer='function(x) core.set_setting("%{id}", x) end' change-on-release='%{changeonrelease}'
+        sub-consumer='function(x) update_setting(x, "%{id}", "%{name}", "%{postfix}") end'/>
 </panel>
diff --git a/src/data/dynamic_fwd.hpp b/src/data/dynamic_fwd.hpp
index 1a398edd..6faff946 100644
--- a/src/data/dynamic_fwd.hpp
+++ b/src/data/dynamic_fwd.hpp
@@ -6,6 +6,7 @@
 #include <memory>
 #include <string>
 #include <variant>
+#include <functional>
 
 namespace dynamic {
     class Map;
@@ -27,6 +28,8 @@ namespace dynamic {
         bool,
         integer_t
     >;
+
+    using to_string_func = std::function<std::string(const Value&)>;
 }
 
 #endif // DATA_DYNAMIC_FWD_HPP_
diff --git a/src/graphics/ui/elements/TrackBar.cpp b/src/graphics/ui/elements/TrackBar.cpp
index 816b4ae8..ab90b763 100644
--- a/src/graphics/ui/elements/TrackBar.cpp
+++ b/src/graphics/ui/elements/TrackBar.cpp
@@ -50,6 +50,10 @@ void TrackBar::setConsumer(doubleconsumer consumer) {
     this->consumer = std::move(consumer);
 }
 
+void TrackBar::setSubConsumer(doubleconsumer consumer) {
+    this->subconsumer = std::move(consumer);
+}
+
 void TrackBar::mouseMove(GUI*, int x, int) {
     glm::vec2 pos = calcPos();
     value = x - trackWidth/2;
@@ -63,6 +67,9 @@ void TrackBar::mouseMove(GUI*, int x, int) {
     if (consumer && !changeOnRelease) {
         consumer(value);
     }
+    if (subconsumer) {
+        subconsumer(value);
+    }
 }
 
 void TrackBar::mouseRelease(GUI*, int, int) {
diff --git a/src/graphics/ui/elements/TrackBar.hpp b/src/graphics/ui/elements/TrackBar.hpp
index 9a9fcad1..6e055e61 100644
--- a/src/graphics/ui/elements/TrackBar.hpp
+++ b/src/graphics/ui/elements/TrackBar.hpp
@@ -2,6 +2,7 @@
 #define GRAPHICS_UI_ELEMENTS_TRACKBAR_HPP_
 
 #include "UINode.hpp"
+#include "../../../data/dynamic_fwd.hpp"
 
 namespace gui {
     class TrackBar : public UINode {
@@ -9,6 +10,7 @@ namespace gui {
         glm::vec4 trackColor {1.0f, 1.0f, 1.0f, 0.4f};
         doublesupplier supplier = nullptr;
         doubleconsumer consumer = nullptr;
+        doubleconsumer subconsumer = nullptr;
         double min;
         double max;
         double value;
@@ -23,8 +25,9 @@ namespace gui {
                  int trackWidth=12);
         virtual void draw(const DrawContext* pctx, Assets* assets) override;
 
-        virtual void setSupplier(doublesupplier supplier);
-        virtual void setConsumer(doubleconsumer consumer);
+        virtual void setSupplier(doublesupplier);
+        virtual void setConsumer(doubleconsumer);
+        virtual void setSubConsumer(doubleconsumer);
 
         virtual void mouseMove(GUI*, int x, int y) override;
         virtual void mouseRelease(GUI*, int x, int y) override;
diff --git a/src/graphics/ui/gui_xml.cpp b/src/graphics/ui/gui_xml.cpp
index e4e8310b..297ee4ac 100644
--- a/src/graphics/ui/gui_xml.cpp
+++ b/src/graphics/ui/gui_xml.cpp
@@ -392,26 +392,26 @@ static std::shared_ptr<UINode> readImage(UiXmlReader& reader, const xml::xmlelem
 }
 
 static std::shared_ptr<UINode> readTrackBar(UiXmlReader& reader, const xml::xmlelement& element) {
-    float min = element->attr("min", "0.0").asFloat();
-    float max = element->attr("max", "1.0").asFloat();
+    const auto& env = reader.getEnvironment();
+    const auto& file = reader.getFilename();
+    float minv = element->attr("min", "0.0").asFloat();
+    float maxv = element->attr("max", "1.0").asFloat();
     float def = element->attr("value", "0.0").asFloat();
     float step = element->attr("step", "1.0").asFloat();
     int trackWidth = element->attr("track-width", "12").asInt();
-    auto bar = std::make_shared<TrackBar>(min, max, def, step, trackWidth);
+    auto bar = std::make_shared<TrackBar>(minv, maxv, def, step, trackWidth);
     _readUINode(reader, element, *bar);
     if (element->has("consumer")) {
         bar->setConsumer(scripting::create_number_consumer(
-            reader.getEnvironment(),
-            element->attr("consumer").getText(),
-            reader.getFilename()
-        ));
+            env, element->attr("consumer").getText(), file));
+    }
+    if (element->has("sub-consumer")) {
+        bar->setSubConsumer(scripting::create_number_consumer(
+            env, element->attr("sub-consumer").getText(), file));
     }
     if (element->has("supplier")) {
         bar->setSupplier(scripting::create_number_supplier(
-            reader.getEnvironment(),
-            element->attr("supplier").getText(),
-            reader.getFilename()
-        ));
+            env, element->attr("supplier").getText(), file));
     }
     if (element->has("track-color")) {
         bar->setTrackColor(element->attr("track-color").asColor());
diff --git a/src/logic/scripting/scripting_functional.cpp b/src/logic/scripting/scripting_functional.cpp
index b758f336..b3ad82af 100644
--- a/src/logic/scripting/scripting_functional.cpp
+++ b/src/logic/scripting/scripting_functional.cpp
@@ -2,6 +2,7 @@
 
 #include "lua/lua_engine.hpp"
 #include "../../debug/Logger.hpp"
+#include "../../coders/json.hpp"
 #include "../../util/stringutil.hpp"
 
 using namespace scripting;
@@ -177,3 +178,25 @@ vec2supplier scripting::create_vec2_supplier(
         return glm::vec2(0, 0);
     };
 }
+
+dynamic::to_string_func scripting::create_tostring(
+    const scriptenv& env,
+    const std::string& src,
+    const std::string& file
+) {
+    auto L = lua::get_main_thread();
+    try {
+        lua::loadbuffer(L, *env, src, file);
+        lua::call(L, 0, 1);
+        auto func = lua::create_lambda(L);
+        return [func](const dynamic::Value& value) {
+            auto result = func({value});
+            return json::stringify(result, true, "  ");
+        };
+    } catch (const lua::luaerror& err) {
+        logger.error() << err.what();
+        return [](const auto& value) {
+            return json::stringify(value, true, "  ");
+        };
+    }
+}
diff --git a/src/logic/scripting/scripting_functional.hpp b/src/logic/scripting/scripting_functional.hpp
index 9b1cc715..01141262 100644
--- a/src/logic/scripting/scripting_functional.hpp
+++ b/src/logic/scripting/scripting_functional.hpp
@@ -72,6 +72,12 @@ namespace scripting {
         const std::string& src, 
         const std::string& file="<string>"
     );
+
+    dynamic::to_string_func create_tostring(
+        const scriptenv& env,
+        const std::string& src,
+        const std::string& file="<string>"
+    );
 }
 
 #endif // LOGIC_SCRIPTING_SCRIPTING_FUNCTIONAL_HPP_