diff --git a/example/Vulkan/SceneTree.cpp b/example/Vulkan/SceneTree.cpp
index f1393083..9a512743 100644
--- a/example/Vulkan/SceneTree.cpp
+++ b/example/Vulkan/SceneTree.cpp
@@ -17,6 +17,8 @@ constexpr uint32_t SCREEN_HEIGHT=128;
 
 class TestApp:public CameraAppFramework
 {
+    Color4f color;
+
 private:
 
     double      start_time;
@@ -27,6 +29,8 @@ private:
     vulkan::Material *          material            =nullptr;
     vulkan::MaterialInstance *  material_instance   =nullptr;
 
+    vulkan::Buffer *            ubo_color           =nullptr;
+
     vulkan::Renderable *        renderable_object   =nullptr;
 
     vulkan::Pipeline *          pipeline_line       =nullptr;
@@ -67,6 +71,11 @@ private:
     {
         if(!InitCameraUBO(material_instance,"world"))
             return(false);
+            
+        color.Set(1,1,0,1);
+        ubo_color=device->CreateUBO(sizeof(Color4f),&color);
+
+        material_instance->BindUBO("color_material",ubo_color);
 
         material_instance->Update();
         return(true);
diff --git a/res/shader/OnlyPosition3D.vert b/res/shader/OnlyPosition3D.vert
index bc46aa1f..c6d3b259 100644
--- a/res/shader/OnlyPosition3D.vert
+++ b/res/shader/OnlyPosition3D.vert
@@ -2,24 +2,28 @@
 
 layout(location = 0) in vec3 Vertex;
 
-layout(binding = 0) uniform WorldMatrix
+layout(binding=0) uniform WorldMatrix     // hgl/math/Math.h
 {
     mat4 ortho;
+
     mat4 projection;
+    mat4 inverse_projection;
+
     mat4 modelview;
+    mat4 inverse_modelview;
+
     mat4 mvp;
+    mat4 inverse_mvp;
+
     vec4 view_pos;
+    vec2 resolution;
 } world;
 
 layout(push_constant) uniform Consts {
     mat4 local_to_world;
 } pc;
 
-layout(location = 0) out vec4 FragmentColor;
-
 void main()
 {
-    FragmentColor=vec4(1.0);
-
     gl_Position=vec4(Vertex,1.0)*(pc.local_to_world*world.mvp);
 }