diff --git a/src/assets/assetload_funcs.cpp b/src/assets/assetload_funcs.cpp
index 78d89a0b..88dd66bd 100644
--- a/src/assets/assetload_funcs.cpp
+++ b/src/assets/assetload_funcs.cpp
@@ -71,8 +71,8 @@ static auto process_program(const ResPaths& paths, const std::string& filename)
 
     auto& preprocessor = *Shader::preprocessor;
 
-    auto vertex = preprocessor.process(vertexFile, vertexSource);
-    auto fragment = preprocessor.process(fragmentFile, fragmentSource);
+    auto vertex = preprocessor.process(vertexFile, vertexSource, false, {});
+    auto fragment = preprocessor.process(fragmentFile, fragmentSource, false, {});
     return std::make_pair(vertex, fragment);
 }
 
@@ -121,7 +121,7 @@ assetload::postfunc assetload::posteffect(
 
     auto& preprocessor = *Shader::preprocessor;
     preprocessor.addHeader(
-        "__effect__", preprocessor.process(effectFile, effectSource, true)
+        "__effect__", preprocessor.process(effectFile, effectSource, true, {})
     );
 
     auto [vertex, fragment] = process_program(paths, SHADERS_FOLDER + "/effect");
diff --git a/src/coders/GLSLExtension.cpp b/src/coders/GLSLExtension.cpp
index 8105b09e..5d53cb35 100644
--- a/src/coders/GLSLExtension.cpp
+++ b/src/coders/GLSLExtension.cpp
@@ -22,6 +22,10 @@ void GLSLExtension::setPaths(const ResPaths* paths) {
     this->paths = paths;
 }
 
+void GLSLExtension::setTraceOutput(bool enabled) {
+    this->traceOutput = enabled;
+}
+
 void GLSLExtension::loadHeader(const std::string& name) {
     if (paths == nullptr) {
         return;
@@ -29,7 +33,7 @@ void GLSLExtension::loadHeader(const std::string& name) {
     io::path file = paths->find("shaders/lib/" + name + ".glsl");
     std::string source = io::read_string(file);
     addHeader(name, {});
-    addHeader(name, process(file, source, true));
+    addHeader(name, process(file, source, true, {}));
 }
 
 void GLSLExtension::addHeader(const std::string& name, ProcessingResult header) {
@@ -123,13 +127,22 @@ static Value default_value_for(Type type) {
 
 class GLSLParser : public BasicParser<char> {
 public:
-    GLSLParser(GLSLExtension& glsl, std::string_view file, std::string_view source, bool header)
+    GLSLParser(
+        GLSLExtension& glsl,
+        std::string_view file,
+        std::string_view source,
+        bool header,
+        const std::vector<std::string>& defines
+    )
         : BasicParser(file, source), glsl(glsl) {
         if (!header) {
             ss << "#version " << GLSLExtension::VERSION << '\n';
-        }
-        for (auto& entry : glsl.getDefines()) {
-            ss << "#define " << entry.first << " " << entry.second << '\n';
+            for (auto& entry : defines) {
+                ss << "#define " << entry << '\n';
+            }
+            for (auto& entry : defines) {
+                ss << "#define " << entry << '\n';
+            }
         }
         uint linenum = 1;
         source_line(ss, linenum);
@@ -289,10 +302,34 @@ private:
     std::stringstream ss;
 };
 
+static void trace_output(
+    const io::path& file,
+    const std::string& source,
+    const GLSLExtension::ProcessingResult& result
+) {
+    std::stringstream ss;
+    ss << "export:trace/" << file.name();
+    io::path outfile = ss.str();
+    try {
+        io::create_directories(outfile.parent());
+        io::write_string(outfile, result.code);
+    } catch (const std::runtime_error& err) {
+        logger.error() << "error on saving GLSLExtension::preprocess output ("
+            << outfile.string() << "): " << err.what();
+    }
+}
+
 GLSLExtension::ProcessingResult GLSLExtension::process(
-    const io::path& file, const std::string& source, bool header
+    const io::path& file,
+    const std::string& source,
+    bool header,
+    const std::vector<std::string>& defines
 ) {
     std::string filename = file.string();
-    GLSLParser parser(*this, filename, source, header);
-    return parser.process();
+    GLSLParser parser(*this, filename, source, header, defines);
+    auto result = parser.process();
+    if (traceOutput) {
+        trace_output(file, source, result);
+    }
+    return result;
 }
diff --git a/src/coders/GLSLExtension.hpp b/src/coders/GLSLExtension.hpp
index b61ca512..53f52930 100644
--- a/src/coders/GLSLExtension.hpp
+++ b/src/coders/GLSLExtension.hpp
@@ -5,6 +5,7 @@
 #include <vector>
 
 #include "io/io.hpp"
+#include "data/setting.hpp"
 #include "graphics/core/PostEffect.hpp"
 
 class ResPaths;
@@ -19,6 +20,7 @@ public:
     };
 
     void setPaths(const ResPaths* paths);
+    void setTraceOutput(bool enabled);
 
     void define(const std::string& name, std::string value);
     void undefine(const std::string& name);
@@ -37,7 +39,8 @@ public:
     ProcessingResult process(
         const io::path& file,
         const std::string& source,
-        bool header = false
+        bool header,
+        const std::vector<std::string>& defines
     );
 
     static inline std::string VERSION = "330 core";
@@ -46,4 +49,5 @@ private:
     std::unordered_map<std::string, std::string> defines;
 
     const ResPaths* paths = nullptr;
+    bool traceOutput = false;
 };
diff --git a/src/engine/Engine.cpp b/src/engine/Engine.cpp
index 0288d609..212765f3 100644
--- a/src/engine/Engine.cpp
+++ b/src/engine/Engine.cpp
@@ -143,6 +143,12 @@ void Engine::initializeClient() {
         },
         true
     ));
+    keepAlive(settings.debug.doTraceShaders.observe(
+        [](bool value) {
+            Shader::preprocessor->setTraceOutput(value);
+        },
+        true
+    ));
 }
 
 void Engine::initialize(CoreParameters coreParameters) {
diff --git a/src/graphics/core/Shader.cpp b/src/graphics/core/Shader.cpp
index da6ea342..8cc6f202 100644
--- a/src/graphics/core/Shader.cpp
+++ b/src/graphics/core/Shader.cpp
@@ -2,7 +2,6 @@
 
 #include <exception>
 #include <fstream>
-#include <iostream>
 #include <sstream>
 #include <filesystem>
 
@@ -138,15 +137,21 @@ glshader compile_shader(GLenum type, const GLchar* source, const std::string& fi
 }
 
 static GLuint compile_program(
-    const Shader::Source& vertexSource, const Shader::Source& fragmentSource
+    const Shader::Source& vertexSource,
+    const Shader::Source& fragmentSource,
+    const std::vector<std::string>& defines
 ) {
     auto& preprocessor = *Shader::preprocessor;
 
     auto vertexCode = std::move(
-        preprocessor.process(vertexSource.file, vertexSource.code).code
+        preprocessor
+            .process(vertexSource.file, vertexSource.code, false, defines)
+            .code
     );
     auto fragmentCode = std::move(
-        preprocessor.process(fragmentSource.file, fragmentSource.code).code
+        preprocessor
+            .process(fragmentSource.file, fragmentSource.code, false, defines)
+            .code
     );
 
     const GLchar* vCode = vertexCode.c_str();
@@ -176,8 +181,8 @@ static GLuint compile_program(
     return program;
 }
 
-void Shader::recompile() {
-    GLuint newProgram = compile_program(vertexSource, fragmentSource);
+void Shader::recompile(const std::vector<std::string>& defines) {
+    GLuint newProgram = compile_program(vertexSource, fragmentSource, defines);
     glDeleteProgram(id);
     id = newProgram;
     uniformLocations.clear();
@@ -188,7 +193,7 @@ std::unique_ptr<Shader> Shader::create(
     Source&& vertexSource, Source&& fragmentSource
 ) {
     return std::make_unique<Shader>(
-        compile_program(vertexSource, fragmentSource),
+        compile_program(vertexSource, fragmentSource, {}),
         std::move(vertexSource),
         std::move(fragmentSource)
     );
diff --git a/src/graphics/core/Shader.hpp b/src/graphics/core/Shader.hpp
index 4808172e..62698063 100644
--- a/src/graphics/core/Shader.hpp
+++ b/src/graphics/core/Shader.hpp
@@ -4,6 +4,7 @@
 
 #include <string>
 #include <memory>
+#include <vector>
 #include <unordered_map>
 #include <glm/glm.hpp>
 
@@ -50,7 +51,7 @@ public:
     void uniform4v(const std::string& name, int length, const float* v);
 
     /// @brief Re-preprocess source code and re-compile shader program
-    void recompile();
+    void recompile(const std::vector<std::string>& defines);
 
     /// @brief Create shader program using vertex and fragment shaders source.
     /// @return linked shader program containing vertex and fragment shaders
diff --git a/src/graphics/render/WorldRenderer.cpp b/src/graphics/render/WorldRenderer.cpp
index 099dd989..faa8fdc6 100644
--- a/src/graphics/render/WorldRenderer.cpp
+++ b/src/graphics/render/WorldRenderer.cpp
@@ -321,11 +321,13 @@ void WorldRenderer::renderFrame(
         prevCTShaderSettings.shadows != currentSettings.shadows ||
         prevCTShaderSettings.ssao != currentSettings.ssao
     ) {
-        Shader::preprocessor->setDefined("ENABLE_SHADOWS", currentSettings.shadows);
-        Shader::preprocessor->setDefined("ENABLE_SSAO", currentSettings.ssao);
-        Shader::preprocessor->setDefined("ADVANCED_RENDER", currentSettings.advancedRender);
+        std::vector<std::string> defines;
+        if (currentSettings.shadows) defines.emplace_back("ENABLE_SHADOWS");
+        if (currentSettings.ssao) defines.emplace_back("ENABLE_SSAO");
+        if (currentSettings.advancedRender) defines.emplace_back("ADVANCED_RENDER");
+
         for (auto shader : affectedShaders) {
-            shader->recompile();
+            shader->recompile(defines);
         }
         prevCTShaderSettings = currentSettings;
     }
diff --git a/src/io/settings_io.cpp b/src/io/settings_io.cpp
index 53a669ad..ea9a7bf5 100644
--- a/src/io/settings_io.cpp
+++ b/src/io/settings_io.cpp
@@ -89,6 +89,7 @@ SettingsHandler::SettingsHandler(EngineSettings& settings) {
     builder.section("debug");
     builder.add("generator-test-mode", &settings.debug.generatorTestMode);
     builder.add("do-write-lights", &settings.debug.doWriteLights);
+    builder.add("do-trace-shaders", &settings.debug.doTraceShaders);
     builder.add("enable-experimental", &settings.debug.enableExperimental);
 }
 
diff --git a/src/settings.hpp b/src/settings.hpp
index 0cb680f0..966e9758 100644
--- a/src/settings.hpp
+++ b/src/settings.hpp
@@ -95,6 +95,8 @@ struct DebugSettings {
     FlagSetting generatorTestMode {false};
     /// @brief Write lights cache
     FlagSetting doWriteLights {true};
+    /// @brief Write preprocessed shaders code to user:export
+    FlagSetting doTraceShaders {false};
     /// @brief Enable experimental optimizations and features
     FlagSetting enableExperimental {false};
 };
diff --git a/test/coders/GLSLExtension.cpp b/test/coders/GLSLExtension.cpp
index bcdd5316..c6936da4 100644
--- a/test/coders/GLSLExtension.cpp
+++ b/test/coders/GLSLExtension.cpp
@@ -11,7 +11,7 @@ TEST(GLSLExtension, processing) {
             "float sum(float a, float b) {\n"
             "    return a + b;\n"
             "}\n",
-            true
+            true, {}
         )
     );
     try {
@@ -27,7 +27,7 @@ TEST(GLSLExtension, processing) {
             "    vec4 color = texture(u_screen, v_uv);\n"
             "    return mix(color, 1.0 - color, p_intensity);\n"
             "}\n",
-        false);
+        false, {});
         std::cout << processed.code << std::endl;
     } catch (const parsing_error& err) {
         std::cerr << err.errorLog() << std::endl;