Cycles: Further tweak for Decoupled Ray Marching

Avoid some if checks when probalistic_scatter is false.

Differential Revision: https://developer.blender.org/D743

3 files changed, 17 insertions, 18 deletions

diff --git a/intern/cycles/kernel/kernel_path.h b/intern/cycles/kernel/kernel_path.h
index d0e7f972c53..7c06a895249 100644
--- a/intern/cycles/kernel/kernel_path.h
+++ b/intern/cycles/kernel/kernel_path.h
@@ -850,16 +850,16 @@ ccl_device float4 kernel_branched_path_integrate(KernelGlobals *kg, RNG *rng, in
 
 					VolumeIntegrateResult result = kernel_volume_decoupled_scatter(kg,
 						&ps, &pray, &volume_sd, &tp, rphase, rscatter, &volume_segment, NULL, false);
+						
+					kernel_assert(result == VOLUME_PATH_SCATTERED);
 
-					if(result == VOLUME_PATH_SCATTERED) {
-						if(kernel_path_volume_bounce(kg, rng, &volume_sd, &tp, &ps, &L, &pray, num_samples_inv)) {
-							kernel_path_indirect(kg, rng, pray, tp*num_samples_inv, num_samples, ps, &L);
+					if(kernel_path_volume_bounce(kg, rng, &volume_sd, &tp, &ps, &L, &pray, num_samples_inv)) {
+						kernel_path_indirect(kg, rng, pray, tp*num_samples_inv, num_samples, ps, &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);
-						}
+						/* 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_path_volume.h b/intern/cycles/kernel/kernel_path_volume.h
index 5e47a3ea6ac..e7047f0ab85 100644
--- a/intern/cycles/kernel/kernel_path_volume.h
+++ b/intern/cycles/kernel/kernel_path_volume.h
@@ -144,9 +144,8 @@ ccl_device void kernel_branched_path_volume_connect_light(KernelGlobals *kg, RNG
 
 				VolumeIntegrateResult result = kernel_volume_decoupled_scatter(kg,
 					state, ray, sd, &tp, rphase, rscatter, segment, (ls.t != FLT_MAX)? &ls.P: NULL, false);
-
-				if(result != VOLUME_PATH_SCATTERED)
-					continue;
+					
+				kernel_assert(result == VOLUME_PATH_SCATTERED);
 
 				/* todo: split up light_sample so we don't have to call it again with new position */
 				lamp_light_sample(kg, i, light_u, light_v, sd->P, &ls);
@@ -195,9 +194,8 @@ ccl_device void kernel_branched_path_volume_connect_light(KernelGlobals *kg, RNG
 
 				VolumeIntegrateResult result = kernel_volume_decoupled_scatter(kg,
 					state, ray, sd, &tp, rphase, rscatter, segment, (ls.t != FLT_MAX)? &ls.P: NULL, false);
-
-				if(result != VOLUME_PATH_SCATTERED)
-					continue;
+					
+				kernel_assert(result == VOLUME_PATH_SCATTERED);
 
 				/* todo: split up light_sample so we don't have to call it again with new position */
 				light_sample(kg, light_t, light_u, light_v, sd->time, sd->P, &ls);
@@ -234,9 +232,8 @@ ccl_device void kernel_branched_path_volume_connect_light(KernelGlobals *kg, RNG
 
 		VolumeIntegrateResult result = kernel_volume_decoupled_scatter(kg,
 			state, ray, sd, &tp, rphase, rscatter, segment, (ls.t != FLT_MAX)? &ls.P: NULL, false);
-
-		if(result != VOLUME_PATH_SCATTERED)
-			return;
+			
+		kernel_assert(result == VOLUME_PATH_SCATTERED);
 
 		/* todo: split up light_sample so we don't have to call it again with new position */
 		light_sample(kg, light_t, light_u, light_v, sd->time, sd->P, &ls);
diff --git a/intern/cycles/kernel/kernel_volume.h b/intern/cycles/kernel/kernel_volume.h
index 8004013552c..49e5f5099d1 100644
--- a/intern/cycles/kernel/kernel_volume.h
+++ b/intern/cycles/kernel/kernel_volume.h
@@ -732,7 +732,9 @@ ccl_device void kernel_volume_decoupled_free(KernelGlobals *kg, VolumeSegment *s
  * scattering, they always scatter if there is any non-zero scattering
  * coefficient.
  *
- * these also do not do emission or modify throughput. */
+ * these also do not do emission or modify throughput. 
+ * 
+ * function is expected to return VOLUME_PATH_SCATTERED when probalistic_scatter is false */
 ccl_device VolumeIntegrateResult kernel_volume_decoupled_scatter(
 	KernelGlobals *kg, PathState *state, Ray *ray, ShaderData *sd,
 	float3 *throughput, float rphase, float rscatter,