diff --git a/src/akari/core/image.cpp b/src/akari/core/image.cpp
index 619b6707..ed21730a 100644
--- a/src/akari/core/image.cpp
+++ b/src/akari/core/image.cpp
@@ -118,7 +118,6 @@ namespace akari {
                 stbi_image_free((void *)data);
             } else {
                 const auto *data = stbi_load(path.string().c_str(), &x, &y, &channel, 0);
-                info("channel={}", channel);
                 image = std::make_shared<RGBAImage>(ivec2(x, y));
                 parallel_for(
                     image->resolution().y,
diff --git a/src/akari/core/parser.cpp b/src/akari/core/parser.cpp
index d465f0bc..4fed8b58 100644
--- a/src/akari/core/parser.cpp
+++ b/src/akari/core/parser.cpp
@@ -195,6 +195,7 @@ namespace akari::sdl {
         ctx.expect("export");
         expect_space(ctx);
         auto var = parse_identifier(ctx);
+        ctx.cur_var = var;
         if (ctx.cur_mod()->exports.find(var) != ctx.cur_mod()->exports.end()) {
             ctx.report_error(fmt::format("{} is already defined", var), ctx.loc);
         }
@@ -204,11 +205,13 @@ namespace akari::sdl {
         auto val = parse(ctx);
         ctx.cur_mod()->exports[var] = val;
         expect_newline(ctx);
+        ctx.cur_var = "";
     }
     void Parser::parse_let(ParserContext &ctx) {
         ctx.expect("let");
         expect_space(ctx);
         auto var = parse_identifier(ctx);
+        ctx.cur_var = var;
         if (ctx.cur_mod()->locals.find(var) != ctx.cur_mod()->locals.end()) {
             ctx.report_error(fmt::format("{} is already defined", var), ctx.loc);
         }
@@ -218,6 +221,7 @@ namespace akari::sdl {
         auto val = parse(ctx);
         ctx.cur_mod()->locals[var] = val;
         expect_newline(ctx);
+        ctx.cur_var = "";
     }
     Value Parser::parse(ParserContext &ctx) {
         auto c = ctx.peek();
diff --git a/src/akari/core/parser.h b/src/akari/core/parser.h
index cb3a508a..5b9c86fd 100644
--- a/src/akari/core/parser.h
+++ b/src/akari/core/parser.h
@@ -164,7 +164,7 @@ namespace akari::sdl {
     struct AKR_EXPORT ParserContext {
         std::vector<P<Module>> mod_stack;
         P<Module> main;
-
+        std::string cur_var;
         SourceLoc loc;
         const std::string &source;
         size_t pos = 0;
diff --git a/src/akari/render/lights/area.cpp b/src/akari/render/lights/area.cpp
index 2a2bf00d..4669fb7b 100644
--- a/src/akari/render/lights/area.cpp
+++ b/src/akari/render/lights/area.cpp
@@ -87,6 +87,9 @@ namespace akari::render {
                 AKR_ASSERT_THROW(color);
             }
         }
+        void finalize()override{
+            color->finalize();
+        }
     };
     AKR_EXPORT_NODE(AreaLight, AreaLightNode);
 } // namespace akari::render
\ No newline at end of file
diff --git a/src/akari/render/lights/envmap.cpp b/src/akari/render/lights/envmap.cpp
index 56137b7b..7a61af14 100644
--- a/src/akari/render/lights/envmap.cpp
+++ b/src/akari/render/lights/envmap.cpp
@@ -140,6 +140,7 @@ namespace akari::render {
             AKR_CHECK(!triangle.has_value());
             return InfiniteAreaLight::create(*scene, transform, envmap->create_texture(allocator), allocator);
         }
+        void finalize() override { envmap->finalize(); }
     };
     AKR_EXPORT_NODE(EnvMap, EnvMapNode);
 } // namespace akari::render
\ No newline at end of file
diff --git a/src/akari/render/material.cpp b/src/akari/render/material.cpp
index 913add9a..92c215da 100644
--- a/src/akari/render/material.cpp
+++ b/src/akari/render/material.cpp
@@ -58,13 +58,18 @@ namespace akari::render {
             if (field == "fraction" || field == "frac") {
                 fraction = resolve_texture(value);
             } else if (field == "first") {
-                mat_A = dyn_cast<MaterialNode>(value.object());
+                mat_A = sg_dyn_cast<MaterialNode>(value.object());
                 AKR_ASSERT_THROW(mat_A);
             } else if (field == "second") {
-                mat_B = dyn_cast<MaterialNode>(value.object());
+                mat_B = sg_dyn_cast<MaterialNode>(value.object());
                 AKR_ASSERT_THROW(mat_B);
             }
         }
+        void finalize() override {
+            fraction->finalize();
+            mat_A->finalize();
+            mat_B->finalize();
+        }
         std::shared_ptr<const Material> create_material(Allocator<> allocator) override {
             return make_pmr_shared<const MixMaterial>(allocator, fraction->create_texture(allocator),
                                                       mat_A->create_material(allocator),
@@ -82,13 +87,14 @@ namespace akari::render {
         void object_field(sdl::Parser &parser, sdl::ParserContext &ctx, const std::string &field,
                           const sdl::Value &value) override {
             if (field == "light") {
-                light_ = dyn_cast<LightNode>(value.object());
+                light_ = sg_dyn_cast<LightNode>(value.object());
                 AKR_ASSERT_THROW(light_);
             }
         }
         std::shared_ptr<const Material> create_material(Allocator<> allocator) override {
             return make_pmr_shared<EmissiveMaterial>(allocator, light_);
         }
+        void finalize() override { light_->finalize(); }
     };
     AKR_EXPORT std::shared_ptr<EmissiveMaterialNode> create_emissive_material() {
         return std::make_shared<EmissiveMaterialNodeImpl>();
diff --git a/src/akari/render/material.h b/src/akari/render/material.h
index 0b521485..30f7973e 100644
--- a/src/akari/render/material.h
+++ b/src/akari/render/material.h
@@ -127,7 +127,7 @@ namespace akari::render {
     class AKR_EXPORT EmissiveMaterialNode : public MaterialNode {
       public:
         [[nodiscard]] std::shared_ptr<EmissiveMaterialNode> as_emissive() override {
-            return dyn_cast<EmissiveMaterialNode>(shared_from_this());
+            return sg_dyn_cast<EmissiveMaterialNode>(shared_from_this());
         }
         [[nodiscard]] virtual std::shared_ptr<LightNode> light() = 0;
     };
@@ -147,7 +147,7 @@ namespace akari::render {
             return create_image_texture(path);
         } else {
             AKR_ASSERT_THROW(value.is_object());
-            auto tex = dyn_cast<TextureNode>(value.object());
+            auto tex = sg_dyn_cast<TextureNode>(value.object());
             AKR_ASSERT_THROW(tex);
             return tex;
         }
diff --git a/src/akari/render/materials/diffuse.cpp b/src/akari/render/materials/diffuse.cpp
index 54d33bdc..92ca8a09 100644
--- a/src/akari/render/materials/diffuse.cpp
+++ b/src/akari/render/materials/diffuse.cpp
@@ -55,6 +55,9 @@ namespace akari::render {
         std::shared_ptr<const Material> create_material(Allocator<> allocator) override {
             return make_pmr_shared<DiffuseMaterial>(allocator, color->create_texture(allocator));
         }
+        void finalize() override {
+            color->finalize();
+        }
     };
     AKR_EXPORT_NODE(DiffuseMaterial, DiffuseMaterialNode)
 } // namespace akari::render
\ No newline at end of file
diff --git a/src/akari/render/materials/glossy.cpp b/src/akari/render/materials/glossy.cpp
index e36d0ebd..2fb2114e 100644
--- a/src/akari/render/materials/glossy.cpp
+++ b/src/akari/render/materials/glossy.cpp
@@ -41,9 +41,7 @@ namespace akari::render {
             auto R = color->evaluate(sp);
             return R;
         }
-        Float tr(const ShadingPoint &sp) const override {
-           return color->tr(sp);
-        }
+        Float tr(const ShadingPoint &sp) const override { return color->tr(sp); }
     };
 
     class GlossyMaterialNode final : public MaterialNode {
@@ -64,6 +62,10 @@ namespace akari::render {
             return make_pmr_shared<GlossyMaterial>(allocator, color->create_texture(allocator),
                                                    roughness->create_texture(allocator));
         }
+        void finalize() override {
+            color->finalize();
+            roughness->finalize();
+        }
     };
     AKR_EXPORT_NODE(GlossyMaterial, GlossyMaterialNode)
 } // namespace akari::render
\ No newline at end of file
diff --git a/src/akari/render/scene.cpp b/src/akari/render/scene.cpp
index fdf4ab89..0dfc3e38 100644
--- a/src/akari/render/scene.cpp
+++ b/src/akari/render/scene.cpp
@@ -171,26 +171,26 @@ namespace akari::render {
     void SceneNode::object_field(sdl::Parser &parser, sdl::ParserContext &ctx, const std::string &field,
                                  const sdl::Value &value) {
         if (field == "camera") {
-            camera = dyn_cast<CameraNode>(value.object());
+            camera = sg_dyn_cast<CameraNode>(value.object());
             AKR_ASSERT_THROW(camera);
         } else if (field == "output") {
             output = value.get<std::string>().value();
         } else if (field == "integrator") {
-            integrator = dyn_cast<IntegratorNode>(value.object());
+            integrator = sg_dyn_cast<IntegratorNode>(value.object());
             AKR_ASSERT_THROW(integrator);
         } else if (field == "shapes") {
             AKR_ASSERT_THROW(value.is_array());
             for (auto shape : value) {
-                shapes.emplace_back(dyn_cast<MeshNode>(shape.object()));
+                shapes.emplace_back(sg_dyn_cast<MeshNode>(shape.object()));
             }
         } else if (field == "sampler") {
-            sampler = dyn_cast<SamplerNode>(value.object());
+            sampler = sg_dyn_cast<SamplerNode>(value.object());
             AKR_ASSERT_THROW(sampler);
         } else if (field == "accelerator") {
-            accel = dyn_cast<AcceleratorNode>(value.object());
+            accel = sg_dyn_cast<AcceleratorNode>(value.object());
             AKR_ASSERT_THROW(accel);
         } else if (field == "envmap") {
-            envmap = dyn_cast<LightNode>(value.object());
+            envmap = sg_dyn_cast<LightNode>(value.object());
             AKR_ASSERT_THROW(envmap);
         }
     }
diff --git a/src/akari/render/scenegraph.cpp b/src/akari/render/scenegraph.cpp
index ea399e55..6f9c3768 100644
--- a/src/akari/render/scenegraph.cpp
+++ b/src/akari/render/scenegraph.cpp
@@ -59,7 +59,11 @@ namespace akari::render {
             if (!pi) {
                 throw std::runtime_error("failed to load plugin");
             }
-            return pi->make_shared();
+            auto object = pi->make_shared();
+            if(!ctx.cur_var.empty()){
+                return std::make_shared<NamedNode>(ctx.cur_var, object);
+            }
+            return object;
         }
     };
     std::shared_ptr<SceneGraphParser> SceneGraphParser::create_parser() {
diff --git a/src/akari/render/scenegraph.h b/src/akari/render/scenegraph.h
index 96a62e26..15661f11 100644
--- a/src/akari/render/scenegraph.h
+++ b/src/akari/render/scenegraph.h
@@ -44,6 +44,7 @@ namespace akari::render {
         virtual void enter(SceneGraphNode *) const {}
         virtual void leave(SceneGraphNode *) const {}
     };
+    class NamedNode;
     class AKR_EXPORT SceneGraphNode : public sdl::Object {
       protected:
         virtual void do_traverse(TraversalCallback *cb) {}
@@ -51,6 +52,7 @@ namespace akari::render {
       public:
         void object_field(sdl::Parser &parser, sdl::ParserContext &ctx, const std::string &field,
                           const sdl::Value &value) override {}
+        virtual bool is_named() const { return false; }
         virtual void on_parameter_change(const std::string &field, const sdl::Value &value) {}
         virtual void commit() {}
         virtual const char *description() { return "unknown"; }
@@ -61,23 +63,57 @@ namespace akari::render {
         }
         virtual void finalize() {}
 
+        template <typename T>
+        inline std::shared_ptr<const T> cast() const;
+
+        template <typename T>
+        inline std::shared_ptr<T> cast();
+
         typedef std::shared_ptr<SceneGraphNode> (*CreateFunc)(void);
     };
     class AKR_EXPORT NamedNode : public SceneGraphNode {
-        std::shared_ptr<SceneGraphNode> underlying;
         std::string name_;
+        std::shared_ptr<SceneGraphNode> underlying_;
 
       public:
+        NamedNode(std::string name, std::shared_ptr<SceneGraphNode> underlying_)
+            : name_(name), underlying_(underlying_) {}
         const std::string &name() { return name_; }
         void object_field(sdl::Parser &parser, sdl::ParserContext &ctx, const std::string &field,
                           const sdl::Value &value) override {
-            return underlying->object_field(parser, ctx, field, value);
+            return underlying_->object_field(parser, ctx, field, value);
         }
-        void commit() override { underlying->commit(); }
-        const char *description() override { return underlying->description(); }
-        void traverse(TraversalCallback *cb) override { underlying->traverse(cb); }
-        void finalize() override { underlying->finalize(); }
+        void commit() override { underlying_->commit(); }
+        const char *description() override { return underlying_->description(); }
+        void traverse(TraversalCallback *cb) override { underlying_->traverse(cb); }
+        void finalize() override { underlying_->finalize(); }
+        bool is_named() const final override { return true; }
+        std::shared_ptr<SceneGraphNode> underlying() { return underlying_; }
     };
+
+    template <typename T>
+    inline std::shared_ptr<const T> SceneGraphNode::cast() const {
+        if (is_named()) {
+            return dyn_cast<const NamedNode>(shared_from_this())->underlying();
+        } else {
+            return dyn_cast<const T>(shared_from_this());
+        }
+    }
+
+    template <typename T>
+    inline std::shared_ptr<T> SceneGraphNode::cast() {
+        if (is_named()) {
+            return dyn_cast<T>(dyn_cast<NamedNode>(shared_from_this())->underlying());
+        } else {
+            return dyn_cast<T>(shared_from_this());
+        }
+    }
+    template <typename U, typename T>
+    std::shared_ptr<U> sg_dyn_cast(const std::shared_ptr<T> &_p) {
+        auto p = dyn_cast<SceneGraphNode>(_p);
+        static_assert(std::is_base_of_v<SceneGraphNode, U>);
+        return p == nullptr ? nullptr : p->cast<U>();
+    }
     class AKR_EXPORT SceneGraphParser : public sdl::Parser {
       public:
         virtual void register_node(const std::string &name, SceneGraphNode::CreateFunc) = 0;
diff --git a/src/akari/render/shapes/akari-mesh.cpp b/src/akari/render/shapes/akari-mesh.cpp
index 5816f823..c04f2e59 100644
--- a/src/akari/render/shapes/akari-mesh.cpp
+++ b/src/akari/render/shapes/akari-mesh.cpp
@@ -75,7 +75,7 @@ namespace akari::render {
             } else if (field == "materials") {
                 AKR_ASSERT_THROW(value.is_array());
                 for (auto mat : value) {
-                    auto m = dyn_cast<MaterialNode>(mat.object());
+                    auto m = sg_dyn_cast<MaterialNode>(mat.object());
                     AKR_ASSERT(m);
                     materials.emplace_back(m);
                 }