I have about 10 objects that move around independently on a plane. Each of these objects needs a ground shadow so I’m using a projector with a fuzzy round cookie as was demonstrated in the lerpz platformer tutorial. Right now this is attached to each of the 10 game objects. My problem is that this has increased the draw calls by 10. What’s the best way to go about batching those shadows to a single draw call? Is there a better approach than the projector for this? My next step will probably be to draw the shadows on planes that move around under the objects and batch those, but I’d like to understand why the projector versions aren’t batching.
Projectors aren’t objects that can be batched. I’d recommend not worrying about it, unless you’ve profiled it and projectors are actually causing performance problems.
In our project we tried 64 projectors to draw a decal type thing on the ground and that makes it unusable on an iPad 3 (2FPS). Turning off projectors moves the FPS to 28-35. According to my low-level game engine dev friends projectors onto terrain shouldn’t be that slow. He guesses there may be a problem like the terrain is redrawing the entire terrain every time (65 times) which would be slow. Making a test project to demonstrate/explore this next. We’ll see.