In order for swap-chain resize to work, every reference to the current (back)buffer need to have been released. So, you can do what you were trying to do, but you need to make sure to release those references manually before doing the resize, via calling Release or freeing the CComPtr, or whatever …

@MitsubishiMagna Forget, I solved the problem




After this line → float2 shadowUV = lightPos.xy * 0.5f + 0.5f;
I should been write this → shadowUV.y = 1 - shadowUV.y;

@undefined thanks

@JoeJ exactly, now I found correct solution

TVertexPT vertices[] = {
   {{-1.0f, -1.0f,  1.0f}, {0.0f, 1.0f}},
   {{ 1.0f, -1.0f,  1.0f}, {1.0f, 1.0f}},
   {{ 1.0f,  1.0f,  1.0f}, {1.0f, 0.0f}},
   {{-1.0f,  1.0f,  1.0f}, {0.0f, 0.0f}…

I solved the problem, my normals was incorrect