Effects/HDR/envmap-prefilter 0.0 1 4 Shaders/HDR/envmap.vert Shaders/HDR/envmap_prefilter.frag Shaders/HDR/math.glsl Shaders/HDR/hammersley.glsl envmap_tex sampler-cube 0 roughness float roughness num_samples int num-samples mip_count int mip-count