Entity now can be linked to a mesh.

Only support cube generated from code no light no nothing

JulietApp/main.cpp

@@ -152,13 +152,13 @@ void JulietApplication::Init(NonNullPtr<Arena>)
             {
                 for (int col = 0; col < kGridSize; ++col)
                 {
-                    MeshID cube = AddCube();
+                    MeshAssetID cubeAsset = GetCubePrimitiveMeshAssetID();
                     float  x    = static_cast<float>(col) * kSpacing - kOffset;
                     float  y    = static_cast<float>(row) * kSpacing - kOffset;
 
                     float  seed     = static_cast<float>(row * kGridSize + col);
                     Matrix rotation = MatrixRotation(seed * 0.73f, seed * 1.17f, seed * 0.53f);
-                    SetMeshTransform(cube, MatrixTranslation(x, y, 0.0f) * rotation);
+                    CreateMeshInstance(cubeAsset, 0, MatrixTranslation(x, y, 0.0f) * rotation);
                 }
             }