I created a small plane geometry (not in full screen) with as material a RenderTexture of a nested scene.
Into the RenderTexture I added a EffectComposer (Bloom effect) so that it only be applied to the RenderTexture. Unfortunately the EffectComposer seems to be creating a fullscreen triangle over the
scene instead of being contained within the texture of my plane geometry Is there a workaround for this ?
I solved the issue by passing the RenderTexture scene & camera to the EffectComposer tag.
I used the onUpdate function from the RenderTexture tag by looping over the __r3f.parent until I retrieve the scene and camera.Then I can apply them to the RenderTexture tag.
Sorry I didn’t manage to reproduce it on your code
The difference in my project is i’m using 2 nested RenderTexture, maybe that’s why it looks to be working.
I will try to make a codepen project of it… In meantime I hope you will figure out a solution.