Rendering to Only an Aux-Texture

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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.

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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.