Cycles: add rejection of inf/nan samples, in principle these should not happen

but this makes it more reliable for now.

Also add an integrator "Clamp" option, to clamp very light samples to a maximum
value. This will reduce accuracy but may help reducing noise and speed up
convergence.

1 files changed, 44 insertions, 0 deletions

diff --git a/intern/cycles/kernel/kernel_accumulate.h b/intern/cycles/kernel/kernel_accumulate.h
index 7ba50973444..a78cfc4dfb7 100644
--- a/intern/cycles/kernel/kernel_accumulate.h
+++ b/intern/cycles/kernel/kernel_accumulate.h
@@ -294,5 +294,49 @@ __device_inline float3 path_radiance_sum(PathRadiance *L)
 #endif
 }
 
+__device_inline void path_radiance_clamp(PathRadiance *L, float3 *L_sum, float clamp)
+{
+	float sum = fabsf(L_sum->x) + fabsf(L_sum->y) + fabsf(L_sum->z);
+
+	if(!isfinite(sum)) {
+		/* invalid value, reject */
+		*L_sum = make_float3(0.0f, 0.0f, 0.0f);
+
+#ifdef __PASSES__
+		if(L->use_light_pass) {
+			L->direct_diffuse = make_float3(0.0f, 0.0f, 0.0f);
+			L->direct_glossy = make_float3(0.0f, 0.0f, 0.0f);
+			L->direct_transmission = make_float3(0.0f, 0.0f, 0.0f);
+
+			L->indirect_diffuse = make_float3(0.0f, 0.0f, 0.0f);
+			L->indirect_glossy = make_float3(0.0f, 0.0f, 0.0f);
+			L->indirect_transmission = make_float3(0.0f, 0.0f, 0.0f);
+
+			L->emission = make_float3(0.0f, 0.0f, 0.0f);
+		}
+#endif
+	}
+	else if(sum > clamp) {
+		/* value to high, scale down */
+		float scale = clamp/sum;
+
+		*L_sum *= scale;
+
+#ifdef __PASSES__
+		if(L->use_light_pass) {
+			L->direct_diffuse *= scale;
+			L->direct_glossy *= scale;
+			L->direct_transmission *= scale;
+
+			L->indirect_diffuse *= scale;
+			L->indirect_glossy *= scale;
+			L->indirect_transmission *= scale;
+
+			L->emission *= scale;
+		}
+#endif
+	}
+}
+
 CCL_NAMESPACE_END