Fix #33838: light render passes for non-progressive integrator were not correct.

3 files changed, 47 insertions, 15 deletions

diff --git a/intern/cycles/kernel/kernel_accumulate.h b/intern/cycles/kernel/kernel_accumulate.h
index d99beb8905a..23bd29840ec 100644
--- a/intern/cycles/kernel/kernel_accumulate.h
+++ b/intern/cycles/kernel/kernel_accumulate.h
@@ -133,6 +133,10 @@ __device_inline void path_radiance_init(PathRadiance *L, int use_light_pass)
 		L->indirect_glossy = make_float3(0.0f, 0.0f, 0.0f);
 		L->indirect_transmission = make_float3(0.0f, 0.0f, 0.0f);
 
+		L->path_diffuse = make_float3(0.0f, 0.0f, 0.0f);
+		L->path_glossy = make_float3(0.0f, 0.0f, 0.0f);
+		L->path_transmission = make_float3(0.0f, 0.0f, 0.0f);
+
 		L->emission = make_float3(0.0f, 0.0f, 0.0f);
 		L->background = make_float3(0.0f, 0.0f, 0.0f);
 		L->ao = make_float3(0.0f, 0.0f, 0.0f);
@@ -156,11 +160,11 @@ __device_inline void path_radiance_bsdf_bounce(PathRadiance *L, float3 *throughp
 			/* first on directly visible surface */
 			float3 value = *throughput*inverse_pdf;
 
-			L->indirect_diffuse = bsdf_eval->diffuse*value;
-			L->indirect_glossy = bsdf_eval->glossy*value;
-			L->indirect_transmission = bsdf_eval->transmission*value;
+			L->path_diffuse = bsdf_eval->diffuse*value;
+			L->path_glossy = bsdf_eval->glossy*value;
+			L->path_transmission = bsdf_eval->transmission*value;
 
-			*throughput = L->indirect_diffuse + L->indirect_glossy + L->indirect_transmission;
+			*throughput = L->path_diffuse + L->path_glossy + L->path_transmission;
 			
 			L->direct_throughput = *throughput;
 		}
@@ -266,22 +270,41 @@ __device_inline void path_radiance_accum_background(PathRadiance *L, float3 thro
 #endif
 }
 
-__device_inline float3 path_radiance_sum(KernelGlobals *kg, PathRadiance *L)
+__device_inline void path_radiance_sum_indirect(PathRadiance *L)
 {
-#ifdef __PASSES__
+	/* this division is a bit ugly, but means we only have to keep track of
+	 * only a single throughput further along the path, here we recover just
+	 * the indirect parth that is not influenced by any particular BSDF type */
 	if(L->use_light_pass) {
-		/* this division is a bit ugly, but means we only have to keep track of
-		 * only a single throughput further along the path, here we recover just
-		 * the indirect parth that is not influenced by any particular BSDF type */
 		L->direct_emission = safe_divide_color(L->direct_emission, L->direct_throughput);
-		L->direct_diffuse += L->indirect_diffuse*L->direct_emission;
-		L->direct_glossy += L->indirect_glossy*L->direct_emission;
-		L->direct_transmission += L->indirect_transmission*L->direct_emission;
+		L->direct_diffuse += L->path_diffuse*L->direct_emission;
+		L->direct_glossy += L->path_glossy*L->direct_emission;
+		L->direct_transmission += L->path_transmission*L->direct_emission;
 
 		L->indirect = safe_divide_color(L->indirect, L->direct_throughput);
-		L->indirect_diffuse *= L->indirect;
-		L->indirect_glossy *= L->indirect;
-		L->indirect_transmission *= L->indirect;
+		L->indirect_diffuse += L->path_diffuse*L->indirect;
+		L->indirect_glossy += L->path_glossy*L->indirect;
+		L->indirect_transmission += L->path_transmission*L->indirect;
+	}
+}
+
+__device_inline void path_radiance_reset_indirect(PathRadiance *L)
+{
+	if(L->use_light_pass) {
+		L->path_diffuse = make_float3(0.0f, 0.0f, 0.0f);
+		L->path_glossy = make_float3(0.0f, 0.0f, 0.0f);
+		L->path_transmission = make_float3(0.0f, 0.0f, 0.0f);
+
+		L->direct_emission = make_float3(0.0f, 0.0f, 0.0f);
+		L->indirect = make_float3(0.0f, 0.0f, 0.0f);
+	}
+}
+
+__device_inline float3 path_radiance_sum(KernelGlobals *kg, PathRadiance *L)
+{
+#ifdef __PASSES__
+	if(L->use_light_pass) {
+		path_radiance_sum_indirect(L);
 
 		float3 L_sum = L->emission
 			+ L->direct_diffuse + L->direct_glossy + L->direct_transmission
diff --git a/intern/cycles/kernel/kernel_path.h b/intern/cycles/kernel/kernel_path.h
index 532c32896d9..1a5df66e6c2 100644
--- a/intern/cycles/kernel/kernel_path.h
+++ b/intern/cycles/kernel/kernel_path.h
@@ -949,6 +949,11 @@ __device float4 kernel_path_non_progressive(KernelGlobals *kg, RNG *rng, int sam
 				kernel_path_indirect(kg, rng, sample*num_samples + j, bsdf_ray, buffer,
 					tp*num_samples_inv, num_samples,
 					min_ray_pdf, bsdf_pdf, ps, rng_offset+PRNG_BOUNCE_NUM, &L);
+
+				/* for render passes, sum and reset indirect light pass variables
+				 * for the next samples */
+				path_radiance_sum_indirect(&L);
+				path_radiance_reset_indirect(&L);
 			}
 		}
 
diff --git a/intern/cycles/kernel/kernel_types.h b/intern/cycles/kernel/kernel_types.h
index 149a4470515..83c157b1f36 100644
--- a/intern/cycles/kernel/kernel_types.h
+++ b/intern/cycles/kernel/kernel_types.h
@@ -255,6 +255,10 @@ typedef struct PathRadiance {
 	float3 indirect_glossy;
 	float3 indirect_transmission;
 
+	float3 path_diffuse;
+	float3 path_glossy;
+	float3 path_transmission;
+
 	float4 shadow;
 } PathRadiance;