Commandbuffer.Blit flips the image until switching to VR

Unity Engine
1

Hi, I am using a commandbuffer for a simple grab of the camera buffer into a temp rendertexture that is used later in a material (a helmet visor). The problem is that the blit flips the Y coordinate of the uvs. I could correct for this by changing the helmet shader (1-uv.y), but when switching into VR it stops flipping the uvs, so I can’t rely on a constant solution. After having switched to VR once, the uvs stop being flipped even after returning to screen mode, which is disconcerting. I am using single pass stereo (NOT instanced). Here is some of the code:

RenderTextureDescriptor desc;
                if (VR.VRController.Instance.VREnabled) {
                    desc = UnityEngine.XR.XRSettings.eyeTextureDesc;
                } else {
                    desc = new RenderTextureDescriptor(Screen.width, Screen.height, RenderTextureFormat.DefaultHDR);
                }
                desc.depthBufferBits = 0;
                holoRenderTex = RenderTexture.GetTemporary(desc);

                blitCommand = new CommandBuffer();
                blitCommand.name = "HUDBlit";
                blitCommand.Blit(BuiltinRenderTextureType.CurrentActive, holoRenderTex);
                holoCamera.AddCommandBuffer(CameraEvent.AfterEverything, blitCommand);
                glassMat.SetTexture("_HoloTex", holoRenderTex);
2

I found a workaround: specifying a blit material using the hidden blit shader fixes the uv flip.

blitMat = new Material(Shader.Find("Hidden/BlitCopy"));
blitCommand.Blit(BuiltinRenderTextureType.CurrentActive, holoRenderTex, blitMat);
3

I have been trying to duplicate your answer but with succese. When I use the 2 parameter version of blitCommand.Blit(src, dest) my result is upside down. If I use the 3 parameter version blitCommand.Blit(src, dest, material) my “_MainTex” is not populated with a texture. Any idea of why this could be the case?