Rendering to Only an Aux-Texture


Ah, nevermind–it looks like what I had in mind won’t quite work to my purposes anyway–at least not as I thus far see. I may end up taking a different approach entirely.

As a result, I’m no longer seeking an answer to this question, for now at least.

I leave the remains of the question below for the sake of transparency, and in case the question or workaround proves useful to others.


In my current project, I’m using FilterManager, and have for some time been rendering to both a colour texture and an auxiliary texture. This rendering is done by having my GLSL shaders write to both “color” and “color2”, and has been working as desired, I believe.

However, I now want to render some additional data to one more auxiliary texture.

The initial setup took some figuring out–“renderSceneInto” doesn’t take a second “auxtex” parameter, but it will take a dictionary of textures that may contain a second auxiliary texture–but I think that I have it working.

The problem lies in how to actually handle this second auxiliary texture.

Specifically, I want two things:

  • First, that most of my shaders to have no effect on it
    • To this end they simply don’t write to “color3”
  • And second, that one particular shader write only to it–having no effect on the colour- or first-auxiliary textures.

And that latter doesn’t seem to be working as I’d hoped: If I don’t include output to “color” and “color2” in the relevant shader, it seems to output something anyway. If I do include output to them, then, well, it affects them, which I don’t want.

I can work around the issue by having the shader output black to “color” and “color2”, and then having the associated geometry render additively, but that feels like a clunky solution–I feel like I’m missing a better approach.