This patch will use compute shaders to create the VBO for hair.
The previous implementation uses tranform feedback.
Timings master (transform feedback with GPU_USAGE_STATIC between 0.000069s and 0.000362s
Timings transform feedback with GPU_USAGE_DEVICE_ONLY. between 0.000057s and 0.000122s
Timings compute shader between 0.000032 and 0.000092s
Future improvements:
* Generate hair Index buffer using compute shaders: currently done single threaded on CPU, easy to add as compute shader.
Reviewed By: fclem
Differential Revision: https://developer.blender.org/D11057
8f9599d17e