Shading and transparency

[Steven V. <is...@ma...>]

Hi all,

I am so glad that there is now a community which I can turn to if I 
have a problem. This time I am working on fixing the race-overlay of my 
game. This was something that used to work once (Either under Quickdraw 
3D or under another version of quesa). The problem is that my 
race-overlay gets shaded with the lights of my scene. I don't want 
this. I want it to be transparent  and not shaded for which I use 
Q3NULLIllumination_New. I am really messing my code up so I might 
actually make things worse. However I suspect this might be a bug in 
quesa. I render in retained mode and I think what happens is that Quesa 
does some alpha sorting routine, but then forgets to check if the 
texture should be rendered with lights on or off.

I can actually make this work, but then all the windows of my cars 
(which should be transparent) become white.

In the case my race overlay gets shaded with the scene lights I do 
something like:

Q3View_StartRendering(view);
Q3Shader_Submit(MyPhongShader, view);
RenderLevel(view);
RenderRaceOverlay(view);
  Q3View_EndRendering(view);

I can make the race overlay render correctly if I do:

Q3View_StartRendering(view);
Q3Shader_Submit(MyPhongShader, view);
RenderLevel(view);
Q3Shader_Submit(MyNullShader, view);
RenderRaceOverlay(view);
  Q3View_EndRendering(view);

But then All the windows of my cars are white

It will also render correctly if do:

Q3View_StartRendering(view);
Q3Shader_Submit(MyNullShader, view);
RenderLevel(view);
RenderRaceOverlay(view);
  Q3View_EndRendering(view);

But then of course everything gets rendered with the NullShader.

And yes, the RaceOverlay is a OrderedDisplayGroup with a 
NULLIlluminationShader added to it.

The null shader does work, because I already use it for my background. 
But I suspect that alpha sorting messes things up.

A screenshot of the problem can be seen here:

http://revaro.spymac.com/ShadingProblem.png

(That the small numbers are lighter is deliberately know by me, I know 
how to fix it)

Steven Verstoep
www.revaro.net