for those out there testing Blender 2.5 daily there is a recent commit that changes the way 2DFilters work for multiple scene files.
In 2.49 all the 2DFilters were running together once per scene. That was producing two issues:
(1) Performance - To run the filters 2X == 2X slower
(2) flexibility of use - Very often we want the filter in the 3D scene but not in the UI for example.
For those reasons I believe that 2DFilters with multiple scenes were very useless or unpredictable. Now each scene can have its own set of 2DFilter. Keep in mind that the 2DFilter of an overlayed scene will still run on top of the main scene + its 2DFilter.
To make it work as before (2.4) you can simply recreate the 2dfilter actuators across the scenes.
Still didn’t get it?
Imagine that we have:
(a) Main Scene
(b) Overlay Scene
in Main Scene the Z Buffer and RGB will be from the main scene.
in Overlay Scene the Z Buffer will be from the Overlay Scene and the RBG buffer is from both [(a + 2D Filter) + b].
So in pseudo code if we have a,b,c,d,e scenes we have: (2DFilterE(2DFilterD(2DFilterC(2DFilterB(2DFilterA(a) + b) + c) + d) + e)