diff --git a/Seele.natvis b/Seele.natvis
index 6921e5f..2c863d3 100644
--- a/Seele.natvis
+++ b/Seele.natvis
@@ -30,7 +30,7 @@
           <Item Name="[value]">value</Item>
       </Expand>
   </Type>
-  <Type Name="Seele::Map&lt;*&gt;">
+  <Type Name="Seele::Map&lt;*,*&gt;">
     <DisplayString>{{ size={_size} }</DisplayString>
     <Expand>
       <Item Name="[size]">_size</Item>
diff --git a/external/slang b/external/slang
index cc22270..4547125 160000
--- a/external/slang
+++ b/external/slang
@@ -1 +1 @@
-Subproject commit cc222702a8d7a1fccf8ad14b256570bcec1554ae
+Subproject commit 4547125ce945140dc10542e9606b225dd06159b8
diff --git a/res/shaders/BasePass.slang b/res/shaders/BasePass.slang
index 11ecd29..659670b 100644
--- a/res/shaders/BasePass.slang
+++ b/res/shaders/BasePass.slang
@@ -15,7 +15,7 @@ layout(set=5)
 ParameterBlock<LightCullingData> pLightCullingData;
 
 [shader("pixel")]
-float4 pixelMain(in MaterialParameter params : PARAMETER) : SV_Target
+float4 fragmentMain(in MaterialParameter params : PARAMETER) : SV_Target
 {
 	let brdf = pMaterial.prepare(params);
     float3 result = float3(0, 0, 0);
@@ -27,5 +27,5 @@ float4 pixelMain(in MaterialParameter params : PARAMETER) : SV_Target
     {
         result += pLightEnv.pointLights[i].illuminate(params, brdf);
     }
-    return float4(1, 1, 0, 1.0f);
+    return float4(result, 1.0f);
 }
diff --git a/res/shaders/Placeholder.json b/res/shaders/Placeholder.json
index 89e2329..08d2e12 100644
--- a/res/shaders/Placeholder.json
+++ b/res/shaders/Placeholder.json
@@ -1,5 +1,5 @@
 {
-	"name": "TerrainMaterial",
+	"name": "Placeholder",
     "params": {
     },
 	"code": [
diff --git a/res/shaders/lib/MaterialParameter.slang b/res/shaders/lib/MaterialParameter.slang
index 77ae5a6..1659ad5 100644
--- a/res/shaders/lib/MaterialParameter.slang
+++ b/res/shaders/lib/MaterialParameter.slang
@@ -7,6 +7,7 @@ struct MaterialParameter
 	float3 tangent;
 	float3 biTangent;
 	float3 viewDir_TS;
+	float3 vertexColor;
 }
 
 struct VertexAttributes
diff --git a/res/shaders/lib/StaticMeshVertexData.slang b/res/shaders/lib/StaticMeshVertexData.slang
index c20d491..dd89d60 100644
--- a/res/shaders/lib/StaticMeshVertexData.slang
+++ b/res/shaders/lib/StaticMeshVertexData.slang
@@ -17,6 +17,7 @@ struct StaticMeshVertexData : IVertexData
 		params.normal = float3(normals[3 * index + 0], normals[3 * index + 1], normals[3 * index + 2]);
 		params.tangent = float3(tangents[3 * index + 0], tangents[3 * index + 1], tangents[3 * index + 2]);
 		params.biTangent = float3(biTangents[3 * index + 0], biTangents[3 * index + 1], biTangents[3 * index + 2]);
+		params.vertexColor = float3(color[3 * index + 0], color[3 * index + 1], color[3 * index + 2]);
 		attributes.parameter = params;
 		attributes.clipPosition = clipPos;
 		return attributes;
@@ -26,4 +27,5 @@ struct StaticMeshVertexData : IVertexData
 	StructuredBuffer<float> normals;
 	StructuredBuffer<float> tangents;
 	StructuredBuffer<float> biTangents;
+	StructuredBuffer<float> color;
 };
diff --git a/src/Editor/Asset/MaterialLoader.cpp b/src/Editor/Asset/MaterialLoader.cpp
index 0fc8483..b6e1ac1 100644
--- a/src/Editor/Asset/MaterialLoader.cpp
+++ b/src/Editor/Asset/MaterialLoader.cpp
@@ -51,7 +51,7 @@ void MaterialLoader::import(MaterialImportArgs args, PMaterialAsset asset)
     uint32 uniformBufferOffset = 0;
     uint32 bindingCounter = 0; // Uniform buffers are always binding 0
     int32 uniformBinding = -1;
-    Map<std::string, OShaderExpression> expressions;
+    Array<OShaderExpression> expressions;
     uint32 key = 0;
     uint32 auxKey = 0;
     Array<std::string> parameters;
@@ -74,7 +74,7 @@ void MaterialLoader::import(MaterialImportArgs args, PMaterialAsset asset)
                 p->data = std::stof(defaultValue.value().get<std::string>());
             }
             parameters.add(p->key);
-            expressions[param.key()] = std::move(p);
+            expressions.add(std::move(p));
         }
         // TODO: ALIGNMENT RULES
         else if(type.compare("float3") == 0)
@@ -91,7 +91,7 @@ void MaterialLoader::import(MaterialImportArgs args, PMaterialAsset asset)
                 p->data = parseVector(defaultValue.value().get<std::string>().c_str());
             }
             parameters.add(p->key); 
-            expressions[param.key()] = std::move(p);
+            expressions.add(std::move(p));
         }
         else if(type.compare("Texture2D") == 0)
         {
@@ -107,7 +107,7 @@ void MaterialLoader::import(MaterialImportArgs args, PMaterialAsset asset)
                 p->data = AssetRegistry::findTexture(""); // this will return placeholder texture
             }
             parameters.add(p->key);
-            expressions[param.key()] = std::move(p);
+            expressions.add(std::move(p));
         }
         else if(type.compare("SamplerState") == 0)
         {
@@ -115,7 +115,7 @@ void MaterialLoader::import(MaterialImportArgs args, PMaterialAsset asset)
             layout->addDescriptorBinding(bindingCounter++, Gfx::SE_DESCRIPTOR_TYPE_SAMPLER);
             p->data = graphics->createSamplerState({});
             parameters.add(p->key);
-            expressions[param.key()] = std::move(p);
+            expressions.add(std::move(p));
         }
         else
         {
@@ -128,14 +128,14 @@ void MaterialLoader::import(MaterialImportArgs args, PMaterialAsset asset)
         if(obj.is_string())
         {
             std::string str = obj.get<std::string>();
-            if (expressions.contains(str))
+            if (expressions.find([&str, &expressions](const OShaderExpression& exp) {return exp->key == str; }) != expressions.end())
             {
                 return str;
             }
             OConstantExpression c = new ConstantExpression(str, ExpressionType::UNKNOWN);
             std::string name = std::format("Const{0}", auxKey++);
             c->key = name;
-            expressions[name] = std::move(c);
+            expressions.add(std::move(c));
             return name;
         }
         else
@@ -156,7 +156,7 @@ void MaterialLoader::import(MaterialImportArgs args, PMaterialAsset asset)
             p->key = name;
             p->inputs["lhs"].source = referenceExpression(obj["lhs"]);
             p->inputs["rhs"].source = referenceExpression(obj["rhs"]);
-            expressions[name] = std::move(p);
+            expressions.add(std::move(p));
         }
         if(exp.compare("Sub") == 0)
         {
@@ -165,7 +165,7 @@ void MaterialLoader::import(MaterialImportArgs args, PMaterialAsset asset)
             p->key = name;
             p->inputs["lhs"].source = referenceExpression(obj["lhs"]);
             p->inputs["rhs"].source = referenceExpression(obj["rhs"]);
-            expressions[name] = std::move(p);
+            expressions.add(std::move(p));
         }
         if(exp.compare("Mul") == 0)
         {
@@ -174,12 +174,12 @@ void MaterialLoader::import(MaterialImportArgs args, PMaterialAsset asset)
             p->key = name;
             p->inputs["lhs"].source = referenceExpression(obj["lhs"]);
             p->inputs["rhs"].source = referenceExpression(obj["rhs"]);
-            expressions[name] = std::move(p);
+            expressions.add(std::move(p));
         }
         if(exp.compare("Swizzle") == 0)
         {
             OSwizzleExpression p = new SwizzleExpression();
-            std::string name = std::format("{0}", key);
+            std::string name = std::format("{0}", key++);
             p->key = name;
             p->inputs["target"].source = referenceExpression(obj["target"]);
             int32 i = 0;
@@ -187,17 +187,17 @@ void MaterialLoader::import(MaterialImportArgs args, PMaterialAsset asset)
             {
                 p->comp[i++] = c.value().get<uint32>();
             }
-            expressions[name] = std::move(p);
+            expressions.add(std::move(p));
         }
         if(exp.compare("Sample") == 0)
         {
             OSampleExpression p = new SampleExpression();
-            std::string name = std::format("{0}", key);
+            std::string name = std::format("{0}", key++);
             p->key = name;
             p->inputs["texture"].source = referenceExpression(obj["texture"]);
             p->inputs["sampler"].source = referenceExpression(obj["sampler"]);
             p->inputs["coords"].source = referenceExpression(obj["coords"]);
-            expressions[name] = std::move(p);
+            expressions.add(std::move(p));
         }
         if(exp.compare("BRDF") == 0)
         {
diff --git a/src/Editor/Asset/MeshLoader.cpp b/src/Editor/Asset/MeshLoader.cpp
index 340e37d..687eec0 100644
--- a/src/Editor/Asset/MeshLoader.cpp
+++ b/src/Editor/Asset/MeshLoader.cpp
@@ -155,6 +155,7 @@ void MeshLoader::loadGlobalMeshes(const aiScene* scene, const Array<PMaterialIns
         Array<Vector> normals(mesh->mNumVertices);
         Array<Vector> tangents(mesh->mNumVertices);
         Array<Vector> biTangents(mesh->mNumVertices);
+        Array<Vector> colors(mesh->mNumVertices);
 
         StaticMeshVertexData* vertexData = StaticMeshVertexData::getInstance();
 
@@ -165,6 +166,14 @@ void MeshLoader::loadGlobalMeshes(const aiScene* scene, const Array<PMaterialIns
             normals[i] = Vector(mesh->mNormals[i].x, mesh->mNormals[i].y, mesh->mNormals[i].z);
             tangents[i] = Vector(mesh->mTangents[i].x, mesh->mTangents[i].y, mesh->mTangents[i].z);
             biTangents[i] = Vector(mesh->mBitangents[i].x, mesh->mBitangents[i].y, mesh->mBitangents[i].z);
+            if(mesh->HasVertexColors(0))
+            {
+                colors[i] = Vector(mesh->mColors[0][i].r, mesh->mColors[0][i].g, mesh->mColors[0][i].b);
+            }
+            else
+            {
+                colors[i] = Vector(1, 1, 1);
+            }
         }
 
         MeshId id = vertexData->allocateVertexData(mesh->mNumVertices);
@@ -173,6 +182,7 @@ void MeshLoader::loadGlobalMeshes(const aiScene* scene, const Array<PMaterialIns
         vertexData->loadNormals(id, normals);
         vertexData->loadTangents(id, tangents);
         vertexData->loadBiTangents(id, biTangents);
+        vertexData->loadColors(id, colors);
 
         Array<uint32> indices(mesh->mNumFaces * 3);
         for (size_t faceIndex = 0; faceIndex < mesh->mNumFaces; ++faceIndex)
diff --git a/src/Engine/Graphics/Shader.cpp b/src/Engine/Graphics/Shader.cpp
index c5e4d0a..c217dca 100644
--- a/src/Engine/Graphics/Shader.cpp
+++ b/src/Engine/Graphics/Shader.cpp
@@ -50,10 +50,17 @@ void ShaderCompiler::registerRenderPass(std::string name, std::string mainFile,
 
 void ShaderCompiler::compile()
 {
-	ShaderPermutation permutation;
 	for (const auto& [name, pass] : passes)
 	{
-		std::strncpy(permutation.vertexMeshFile, pass.mainFile.c_str(), sizeof(permutation.vertexMeshFile));
+		ShaderPermutation permutation;
+		if (pass.useMeshShading)
+		{
+			permutation.setMeshFile(pass.mainFile);
+		}
+		else
+		{
+			permutation.setVertexFile(pass.mainFile);
+		}
 		if (pass.hasFragmentShader)
 		{
 			permutation.setFragmentFile(pass.fragmentFile);
@@ -81,19 +88,22 @@ void ShaderCompiler::compile()
 	}
 }
 
-ShaderCollection& ShaderCompiler::createShaders(ShaderPermutation permutation)
+void ShaderCompiler::createShaders(ShaderPermutation permutation)
 {
 	std::scoped_lock lock(shadersLock);
+	PermutationId perm = PermutationId(permutation);
+	if (shaders.contains(perm))
+		return;
 	ShaderCollection collection;
 
 	ShaderCreateInfo createInfo;
-	createInfo.typeParameter = { Pair<const char*, const char*>("IVertexData", permutation.vertexDataName) };
 	createInfo.name = std::format("Material {0}", permutation.materialName);
 	if (std::strlen(permutation.materialName) > 0)
 	{
 		createInfo.additionalModules.add(permutation.materialName);
 		createInfo.typeParameter.add(Pair<const char*, const char*>("IMaterial", permutation.materialName));
 	}
+	createInfo.typeParameter.add({ Pair<const char*, const char*>("IVertexData", permutation.vertexDataName) });
 	createInfo.additionalModules.add(permutation.vertexDataName);
 	createInfo.additionalModules.add(permutation.vertexMeshFile);
 	if (permutation.hasFragment)
@@ -131,8 +141,5 @@ ShaderCollection& ShaderCompiler::createShaders(ShaderPermutation permutation)
 		collection.fragmentShader = graphics->createFragmentShader(createInfo);
 	}
 	collection.vertexDeclaration = graphics->createVertexDeclaration(Array<VertexElement>());
-	PermutationId perm = PermutationId(permutation);
 	shaders[perm] = std::move(collection);
-
-	return shaders[perm];
 }
\ No newline at end of file
diff --git a/src/Engine/Graphics/Shader.h b/src/Engine/Graphics/Shader.h
index a41d67f..2adda51 100644
--- a/src/Engine/Graphics/Shader.h
+++ b/src/Engine/Graphics/Shader.h
@@ -148,7 +148,7 @@ public:
         std::string taskFile = "");
 private:
     void compile();
-    ShaderCollection& createShaders(ShaderPermutation permutation);
+    void createShaders(ShaderPermutation permutation);
     std::mutex shadersLock;
     Map<PermutationId, ShaderCollection> shaders;
     Map<std::string, PMaterial> materials;
diff --git a/src/Engine/Graphics/StaticMeshVertexData.cpp b/src/Engine/Graphics/StaticMeshVertexData.cpp
index 77f36dc..1fefcbf 100644
--- a/src/Engine/Graphics/StaticMeshVertexData.cpp
+++ b/src/Engine/Graphics/StaticMeshVertexData.cpp
@@ -61,6 +61,14 @@ void StaticMeshVertexData::loadBiTangents(MeshId id, const Array<Vector>& data)
     dirty = true;
 }
 
+void Seele::StaticMeshVertexData::loadColors(MeshId id, const Array<Vector>& data)
+{
+    uint64 offset = meshOffsets[id];
+    assert(offset + data.size() <= head);
+    std::memcpy(colorData.data() + offset, data.data(), data.size() * sizeof(Vector));
+    dirty = true;
+}
+
 void StaticMeshVertexData::serializeMesh(MeshId id, uint64 numVertices, ArchiveBuffer& buffer)
 {
     uint64 offset = meshOffsets[id];
@@ -69,16 +77,19 @@ void StaticMeshVertexData::serializeMesh(MeshId id, uint64 numVertices, ArchiveB
     Array<Vector> nor(numVertices);
     Array<Vector> tan(numVertices);
     Array<Vector> bit(numVertices);
+    Array<Vector> col(numVertices);
     std::copy(positionData.begin() + offset, positionData.begin() + offset + numVertices, pos.begin());
     std::copy(texCoordsData.begin() + offset, texCoordsData.begin() + offset + numVertices, tex.begin());
     std::copy(normalData.begin() + offset, normalData.begin() + offset + numVertices, nor.begin());
     std::copy(tangentData.begin() + offset, tangentData.begin() + offset + numVertices, tan.begin());
     std::copy(biTangentData.begin() + offset, biTangentData.begin() + offset + numVertices, bit.begin());
+    std::copy(colorData.begin() + offset, colorData.begin() + offset + numVertices, col.begin());
     Serialization::save(buffer, pos);
     Serialization::save(buffer, tex);
     Serialization::save(buffer, nor);
     Serialization::save(buffer, tan);
     Serialization::save(buffer, bit);
+    Serialization::save(buffer, col);
 }
 
 void StaticMeshVertexData::deserializeMesh(MeshId id, ArchiveBuffer& buffer)
@@ -88,16 +99,19 @@ void StaticMeshVertexData::deserializeMesh(MeshId id, ArchiveBuffer& buffer)
     Array<Vector> nor;
     Array<Vector> tan;
     Array<Vector> bit;
+    Array<Vector> col;
     Serialization::load(buffer, pos);
     Serialization::load(buffer, tex);
     Serialization::load(buffer, nor);
     Serialization::load(buffer, tan);
     Serialization::load(buffer, bit);
+    Serialization::load(buffer, col);
     loadPositions(id, pos);
     loadTexCoords(id, tex);
     loadNormals(id, nor);
     loadTangents(id, tan);
     loadBiTangents(id, bit);
+    loadBiTangents(id, col);
 }
 
 void StaticMeshVertexData::init(Gfx::PGraphics graphics)
@@ -109,6 +123,7 @@ void StaticMeshVertexData::init(Gfx::PGraphics graphics)
     descriptorLayout->addDescriptorBinding(2, Gfx::SE_DESCRIPTOR_TYPE_STORAGE_BUFFER);
     descriptorLayout->addDescriptorBinding(3, Gfx::SE_DESCRIPTOR_TYPE_STORAGE_BUFFER);
     descriptorLayout->addDescriptorBinding(4, Gfx::SE_DESCRIPTOR_TYPE_STORAGE_BUFFER);
+    descriptorLayout->addDescriptorBinding(5, Gfx::SE_DESCRIPTOR_TYPE_STORAGE_BUFFER);
     descriptorLayout->create();
     descriptorSet = descriptorLayout->allocateDescriptorSet();
 }
@@ -141,6 +156,7 @@ void StaticMeshVertexData::resizeBuffers()
     normals = graphics->createShaderBuffer(createInfo);
     tangents = graphics->createShaderBuffer(createInfo);
     biTangents = graphics->createShaderBuffer(createInfo);
+    colors = graphics->createShaderBuffer(createInfo);
     createInfo.sourceData.size = verticesAllocated * sizeof(Vector2);
     createInfo.stride = sizeof(Vector2);
     texCoords = graphics->createShaderBuffer(createInfo);
@@ -150,6 +166,7 @@ void StaticMeshVertexData::resizeBuffers()
     normalData.resize(verticesAllocated);
     tangentData.resize(verticesAllocated);
     biTangentData.resize(verticesAllocated);
+    colorData.resize(verticesAllocated);
 }
 
 void StaticMeshVertexData::updateBuffers()
@@ -174,6 +191,10 @@ void StaticMeshVertexData::updateBuffers()
         .size = biTangentData.size() * sizeof(Vector),
         .data = (uint8*)biTangentData.data(),
         });
+    colors->updateContents(DataSource{
+        .size = colorData.size() * sizeof(Vector),
+        .data = (uint8*)colorData.data()
+        });
     descriptorLayout->reset();
     descriptorSet = descriptorLayout->allocateDescriptorSet();
     descriptorSet->updateBuffer(0, positions);
@@ -181,5 +202,6 @@ void StaticMeshVertexData::updateBuffers()
     descriptorSet->updateBuffer(2, normals);
     descriptorSet->updateBuffer(3, tangents);
     descriptorSet->updateBuffer(4, biTangents);
+    descriptorSet->updateBuffer(5, colors);
     descriptorSet->writeChanges();
 }
diff --git a/src/Engine/Graphics/StaticMeshVertexData.h b/src/Engine/Graphics/StaticMeshVertexData.h
index 2aacdfc..9729373 100644
--- a/src/Engine/Graphics/StaticMeshVertexData.h
+++ b/src/Engine/Graphics/StaticMeshVertexData.h
@@ -16,6 +16,7 @@ public:
 	void loadNormals(MeshId id, const Array<Vector>& data);
 	void loadTangents(MeshId id, const Array<Vector>& data);
 	void loadBiTangents(MeshId id, const Array<Vector>& data);
+	void loadColors(MeshId id, const Array<Vector>& data);
 	virtual void serializeMesh(MeshId id, uint64 numVertices, ArchiveBuffer& buffer) override;
 	virtual void deserializeMesh(MeshId id, ArchiveBuffer& buffer) override;
 	virtual void init(Gfx::PGraphics graphics) override;
@@ -36,6 +37,8 @@ private:
 	Array<Vector> tangentData;
     Gfx::OShaderBuffer biTangents;
 	Array<Vector> biTangentData;
+	Gfx::OShaderBuffer colors;
+	Array<Vector> colorData;
 	Gfx::ODescriptorLayout descriptorLayout;
 	Gfx::PDescriptorSet descriptorSet;
 };
diff --git a/src/Engine/Graphics/VertexData.cpp b/src/Engine/Graphics/VertexData.cpp
index 26f7e23..9f30742 100644
--- a/src/Engine/Graphics/VertexData.cpp
+++ b/src/Engine/Graphics/VertexData.cpp
@@ -33,6 +33,8 @@ void VertexData::updateMesh(const Component::Transform& transform, PMesh mesh)
         },
         .indexBuffer = mesh->indexBuffer,
     });
+    matInstanceData.materialInstance = mesh->referencedMaterial->getHandle();
+    matInstanceData.materialInstance->updateDescriptor();
     matInstanceData.numMeshes += meshData[mesh->id].size();
 }
 
diff --git a/src/Engine/Material/Material.cpp b/src/Engine/Material/Material.cpp
index 45cbc2b..81ff385 100644
--- a/src/Engine/Material/Material.cpp
+++ b/src/Engine/Material/Material.cpp
@@ -14,7 +14,7 @@ Material::Material(Gfx::PGraphics graphics,
         uint32 uniformDataSize, 
         uint32 uniformBinding, 
         std::string materialName, 
-        Map<std::string, OShaderExpression> expressions,
+        Array<OShaderExpression> expressions,
         Array<std::string> parameter,
         MaterialNode brdf)
     : graphics(graphics)
@@ -112,14 +112,15 @@ void Material::compile()
     codeStream << "struct " << materialName << " : IMaterial {\n";
     for(const auto& parameter : parameters)
     {
-        PShaderParameter handle = PShaderExpression(codeExpressions[parameter]);
+        PShaderParameter handle = PShaderExpression(*codeExpressions.find([&parameter](const OShaderExpression& exp) {return exp->key == parameter; }));
         handle->generateDeclaration(codeStream);
     }
     codeStream << "\ttypedef " << brdf.profile << " BRDF;\n";
     codeStream << "\t" << brdf.profile << " prepare(MaterialParameter input) {\n";
     codeStream << "\t\t" << brdf.profile << " result;\n";
     Map<std::string, std::string> varState;
-    for(const auto& [_, expr] :codeExpressions)
+    // initialize variable state
+    for(const auto& expr :codeExpressions)
     {
         codeStream << expr->evaluate(varState);
     }
diff --git a/src/Engine/Material/Material.h b/src/Engine/Material/Material.h
index 65e4bba..46aaa6a 100644
--- a/src/Engine/Material/Material.h
+++ b/src/Engine/Material/Material.h
@@ -14,7 +14,7 @@ public:
         uint32 uniformDataSize, 
         uint32 uniformBinding, 
         std::string materialName, 
-        Map<std::string, OShaderExpression> expressions,
+        Array<OShaderExpression> expressions,
         Array<std::string> parameter,
         MaterialNode brdf);
     ~Material();
@@ -34,7 +34,7 @@ private:
     uint64 instanceId;
     Gfx::ODescriptorLayout layout;
     std::string materialName;
-    Map<std::string, OShaderExpression> codeExpressions;
+    Array<OShaderExpression> codeExpressions;
     Array<std::string> parameters;
     MaterialNode brdf;
 };
diff --git a/src/Engine/Material/MaterialInstance.cpp b/src/Engine/Material/MaterialInstance.cpp
index 62fc021..2c84115 100644
--- a/src/Engine/Material/MaterialInstance.cpp
+++ b/src/Engine/Material/MaterialInstance.cpp
@@ -10,7 +10,7 @@ MaterialInstance::MaterialInstance()
 
 MaterialInstance::MaterialInstance(uint64 id, 
     Gfx::PGraphics graphics, 
-    Map<std::string, OShaderExpression>& expressions,
+    Array<OShaderExpression>& expressions,
     Array<std::string> params, 
     uint32 uniformBinding, 
     uint32 uniformSize)
@@ -33,7 +33,8 @@ MaterialInstance::MaterialInstance(uint64 id,
     parameters.reserve(params.size());
     for (size_t i = 0; i < params.size(); ++i)
     {
-        Serialization::save(buffer, expressions[params[i]]);
+        const std::string& name = params[i];
+        Serialization::save(buffer, *expressions.find([&name](const OShaderExpression& p) {return p->key == name; }));
         buffer.rewind();
         OShaderParameter param;
         Serialization::load(buffer, param);
diff --git a/src/Engine/Material/MaterialInstance.h b/src/Engine/Material/MaterialInstance.h
index d663dd5..578ce6e 100644
--- a/src/Engine/Material/MaterialInstance.h
+++ b/src/Engine/Material/MaterialInstance.h
@@ -11,7 +11,7 @@ public:
     MaterialInstance();
     MaterialInstance(uint64 id, 
         Gfx::PGraphics graphics, 
-        Map<std::string, OShaderExpression>& expressions,
+        Array<OShaderExpression>& expressions,
         Array<std::string> params, 
         uint32 uniformBinding, 
         uint32 uniformSize);
diff --git a/src/Engine/Material/ShaderExpression.h b/src/Engine/Material/ShaderExpression.h
index 46b53fb..9badcf0 100644
--- a/src/Engine/Material/ShaderExpression.h
+++ b/src/Engine/Material/ShaderExpression.h
@@ -109,7 +109,7 @@ DECLARE_NAME_REF(Gfx, SamplerState)
 struct SamplerParameter : public ShaderParameter
 {
     static constexpr uint64 IDENTIFIER = 0x08;
-    Gfx::PSamplerState data;
+    Gfx::OSamplerState data;
     SamplerParameter() {}
     SamplerParameter(std::string name, uint32 byteOffset, uint32 binding);
     virtual ~SamplerParameter();