Graphics.Blit flips texture

Hey there,

For a project I need to render a game on a very wide but short resolution (5124 x 360), but output that to a regular full HD screen. The game is played on two "ribbons", each taking half of the vertical space (so 5124 x 180). I wrote a screen space shader that wraps those two ribbons so they fit inside the full HD resolution - so far, so good.

However, I also need to use that wrapped output as a texture on a model for testing purposes. I figured I could just blit the output of the camera that shows the wrapped image on screen to the model, but for some reason the texture is vertically flipped after blitting it to another texture.

Code (CSharp):

1. void OnRenderImage(RenderTexture src, RenderTexture dest)
2. {
3.     //Blit the wrapped texture onto the camera output.
4.     Graphics.Blit(_graphicsTexture, dest, _wrapMaterial);
5.     //Blit the camera output onto a texture so it can be applied to a model. The texture in "dest" appears flipped in "_outputTexture".
6.     Graphics.Blit(dest, _outputTexture);
7. }
8.  

There isn't any anti aliasing post processing effect applied to any of the camera's, so that's definitely not it. Any ideas as to what I'm doing wrong?

Thanks,

Thomas

EDIT:

So I had an epiphany on the john (you know, as you do), and I figured that I'd try not reading the output of OnRenderImage directly (the dest render texture), but going over a temporary middle man instead. That solved the issue - hopefully this might help someone else in the future.

Code (CSharp):

1.  
2. void OnRenderImage(RenderTexture src, RenderTexture dest)
3. {
4.     RenderTexture temp = RenderTexture.GetTemporary(1920,1080);
5.     //Wrap the texture.
6.     Graphics.Blit(_graphicsTexture, temp, _wrapMaterial);
7.     //Blit the wrapped texture onto the camera output.
8.     Graphics.Blit(temp, dest);
9.     //Blit the camera output onto the texture for use on a model.
10.     Graphics.Blit(temp, _outputTexture);
11.     RenderTexture.ReleaseTemporary(temp);
12. }

 

From the docs.
You might need to check other image effects on how to use it properly!

 

I am aware of this. However, my shader did not flip the texture on the render texture to which it was applied, so this doesn't apply here. The texture was flipped after copying it from the destination render texture to another one.

 

I know this is an old question. however its the google hit for invert image.
To inverted the image just use

Code (CSharp):

1. Graphics.Blit(src, dest, new Vector2(1.0f, -1.0f), new Vector2(0.0f, 1.0f)

This inverts the Y and offsets from the top. Simple single blit operation.
-andi