diff options
| -rw-r--r-- | intern/cycles/kernel/kernel_montecarlo.h | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/intern/cycles/kernel/kernel_montecarlo.h b/intern/cycles/kernel/kernel_montecarlo.h index acd5086be3a..ac40840133f 100644 --- a/intern/cycles/kernel/kernel_montecarlo.h +++ b/intern/cycles/kernel/kernel_montecarlo.h @@ -85,8 +85,9 @@ ccl_device_inline void sample_uniform_hemisphere( ccl_device_inline void sample_uniform_cone( const float3 N, float angle, float randu, float randv, float3 *omega_in, float *pdf) { - float z = cosf(angle * randu); - float r = sqrtf(max(0.0f, 1.0f - z * z)); + float zMin = cosf(angle); + float z = lerp(zMin, 1.0f, randu); + float r = safe_sqrtf(1.0f - sqr(z)); float phi = M_2PI_F * randv; float x = r * cosf(phi); float y = r * sinf(phi); @@ -94,7 +95,7 @@ ccl_device_inline void sample_uniform_cone( float3 T, B; make_orthonormals(N, &T, &B); *omega_in = x * T + y * B + z * N; - *pdf = 0.5f * M_1_PI_F / (1.0f - cosf(angle)); + *pdf = M_1_2PI_F / (1.0f - zMin); } /* sample uniform point on the surface of a sphere */ |