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iOS Strange Render Lag
Hi I'm making an iOS app and I'm using a first generation iPad to test it. In my scene I have around 20 draw calls, about 3k tris and yet in the iOS internal profiler the cpu-waits-gpu value is over 50 ms and the framerate never goes above 17 fps. Does anyone know why this could be?
Answer by Dreamora · Aug 11, 2011 at 04:01 AM
Fillrate You draw too much with a transparent / cutout shader, at worst even such that are fullscreen and alike.
The fillrate (amount of pixels you can draw per second) is rather limited on the gpu used in 3GS - 4th gen - ipad1, the more you draw, the lower the framerate.
at worst you are using something like the 2D for iOS shader on the board for all stuff instead of just selected ones, which will pretty fast kill it flat out
to overcome the fillrate limitation you must use real geometry that does replicate your form more or less so that optimally little to no overdraw happens. If you are doing 2D, then the 2D Toolkit on the Asset STore has the capability to create better optimized meshes for sprites than quads which are basically the worst possible normally (unless its a tetris game containing out of quads anyway)