anchor.diff:          input.Model.Set this.Model
   
   type SkyRendererComponent (textureKind : TextureKind) =
  -    inherit MeshRendererComponent<SkyInput, Sky> (0, MaterialDescription<SkyInput> (shader, textureKind), Sky ())
  +    inherit Component ()
  +
  +    member val TextureKind = textureKind
  +
  +    member val SkyMesh = SkyMesh ()
  +
  +module Sky =
  +
  +    let update (am : AssetManager) (renderer : Renderer) =
  +
  +        Behavior.Merge
  +            [
  +                Behavior.ComponentAdded (fun _ _ (comp : SkyRendererComponent) ->
  +                    let material = MaterialDescription<SkyInput> (shader, comp.TextureKind) |> am.GetMaterial
  +
  +                    renderer.AddMesh (0, material.Shader :?> Shader<SkyInput>, material.Texture.Buffer, comp.SkyMesh)
  +
  +                )
  +            ]
  
positive.code: open Foom.Renderer
  open Foom.Renderer.RendererSystem
  open Foom.Game.Assets
  
  let octahedron_vtx = 
      [|
  
negative.code: 
  let shader = CreateShader SkyInput 2 (CreateShaderPass (fun _ -> [ Stencil2 ]) "Sky")//CreateShader "Sky" 2 ShaderPass.Stencil2 SkyInput
  
  type SkyMesh () =
      inherit Mesh<SkyInput> (skyVertices, [||], [||])
  
      member val Model = Matrix4x4.CreateScale (100.f)
  