Raster buffer/effect on billboard/ architecture (noobish)

How to use ADD effect on a billboard? I mean to use it to simulate halo*/fire/lightshaft.

In case I wanted to use an effect in postprocessing, can I access the screen buffer** in Panda, or does it have to be done in a shader?

**If I wanted to use more than 8 lights, it would be helpful as well to access this buffer, to combine the partially shaded images. It would also help using some nice HUD effects (like expressing the avatars’ dizziness with wavy effects).

(The Blender internal render engine renders halos this way.)

I know I put kind of unrelated questions in the starting post, I’d just like to know what is possible to do in panda, and whether it’s possible to do commercial quality games, without c++/shader coding.

If you’re just talking about additive rendering, you can simply do:


There are many other options for the ColorBlendAttrib. You may also want to play with disabling the depth buffer, and configuring the render order, depending on the precise effect you’re working for.


Thanks drwr!

Had a look at the Colorblend API ( panda3d.org/apiref.php?page=ColorBlendAttrib), it seems really powerful, like a distinct programming language.
1, Can someone show me an example how e.g. “MGreaterEqual” can be used?
2, Is there a way I can render objects layer by layer and combine them, (I guess it would be slower than working with colorblend API, just being curious)?