Fix T54962: Cycles crash using subsurface scattering texture blur.

4 files changed, 27 insertions, 12 deletions

diff --git a/intern/cycles/kernel/kernel_path_branched.h b/intern/cycles/kernel/kernel_path_branched.h
index 80fcf5b0565..21da4d9308b 100644
--- a/intern/cycles/kernel/kernel_path_branched.h
+++ b/intern/cycles/kernel/kernel_path_branched.h
@@ -368,12 +368,16 @@ ccl_device void kernel_branched_path_subsurface_scatter(KernelGlobals *kg,
 			/* compute lighting with the BSDF closure */
 			for(int hit = 0; hit < num_hits; hit++) {
 				ShaderData bssrdf_sd = *sd;
+				Bssrdf *bssrdf = (Bssrdf *)sc;
+				ClosureType bssrdf_type = sc->type;
+				float bssrdf_roughness = bssrdf->roughness;
 				subsurface_scatter_multi_setup(kg,
 				                               &ss_isect,
 				                               hit,
 				                               &bssrdf_sd,
 				                               &hit_state,
-				                               sc);
+				                               bssrdf_type,
+				                               bssrdf_roughness);
 
 #ifdef __VOLUME__
 				if(need_update_volume_stack) {
diff --git a/intern/cycles/kernel/kernel_path_subsurface.h b/intern/cycles/kernel/kernel_path_subsurface.h
index 962776f21c1..b5a92c74ed5 100644
--- a/intern/cycles/kernel/kernel_path_subsurface.h
+++ b/intern/cycles/kernel/kernel_path_subsurface.h
@@ -64,6 +64,11 @@ bool kernel_path_subsurface_scatter(
 		        sd->object_flag & SD_OBJECT_INTERSECTS_VOLUME;
 #  endif  /* __VOLUME__ */
 
+		/* Closure memory will be overwritten, so read required variables now. */
+		Bssrdf *bssrdf = (Bssrdf *)sc;
+		ClosureType bssrdf_type = sc->type;
+		float bssrdf_roughness = bssrdf->roughness;
+
 		/* compute lighting with the BSDF closure */
 		for(int hit = 0; hit < num_hits; hit++) {
 			/* NOTE: We reuse the existing ShaderData, we assume the path
@@ -74,7 +79,8 @@ bool kernel_path_subsurface_scatter(
 			                               hit,
 			                               sd,
 			                               state,
-			                               sc);
+			                               bssrdf_type,
+			                               bssrdf_roughness);
 
 			kernel_path_surface_connect_light(kg, sd, emission_sd, *throughput, state, L);
 
diff --git a/intern/cycles/kernel/kernel_subsurface.h b/intern/cycles/kernel/kernel_subsurface.h
index a06fbe72ffa..96b717530ce 100644
--- a/intern/cycles/kernel/kernel_subsurface.h
+++ b/intern/cycles/kernel/kernel_subsurface.h
@@ -69,22 +69,21 @@ ccl_device_inline float3 subsurface_scatter_eval(ShaderData *sd,
 }
 
 /* replace closures with a single diffuse bsdf closure after scatter step */
-ccl_device void subsurface_scatter_setup_diffuse_bsdf(KernelGlobals *kg, ShaderData *sd, const ShaderClosure *sc, float3 weight, float3 N)
+ccl_device void subsurface_scatter_setup_diffuse_bsdf(KernelGlobals *kg, ShaderData *sd, ClosureType type, float roughness, float3 weight, float3 N)
 {
 	sd->flag &= ~SD_CLOSURE_FLAGS;
 	sd->num_closure = 0;
 	sd->num_closure_left = kernel_data.integrator.max_closures;
 
-	Bssrdf *bssrdf = (Bssrdf *)sc;
 #ifdef __PRINCIPLED__
-	if(bssrdf->type == CLOSURE_BSSRDF_PRINCIPLED_ID ||
-	   bssrdf->type == CLOSURE_BSSRDF_PRINCIPLED_RANDOM_WALK_ID)
+	if(type == CLOSURE_BSSRDF_PRINCIPLED_ID ||
+	   type == CLOSURE_BSSRDF_PRINCIPLED_RANDOM_WALK_ID)
 	{
 		PrincipledDiffuseBsdf *bsdf = (PrincipledDiffuseBsdf*)bsdf_alloc(sd, sizeof(PrincipledDiffuseBsdf), weight);
 
 		if(bsdf) {
 			bsdf->N = N;
-			bsdf->roughness = bssrdf->roughness;
+			bsdf->roughness = roughness;
 			sd->flag |= bsdf_principled_diffuse_setup(bsdf);
 
 			/* replace CLOSURE_BSDF_PRINCIPLED_DIFFUSE_ID with this special ID so render passes
@@ -92,8 +91,8 @@ ccl_device void subsurface_scatter_setup_diffuse_bsdf(KernelGlobals *kg, ShaderD
 			bsdf->type = CLOSURE_BSDF_BSSRDF_PRINCIPLED_ID;
 		}
 	}
-	else if(CLOSURE_IS_BSDF_BSSRDF(bssrdf->type) ||
-			CLOSURE_IS_BSSRDF(bssrdf->type))
+	else if(CLOSURE_IS_BSDF_BSSRDF(type) ||
+			CLOSURE_IS_BSSRDF(type))
 #endif  /* __PRINCIPLED__ */
 	{
 		DiffuseBsdf *bsdf = (DiffuseBsdf*)bsdf_alloc(sd, sizeof(DiffuseBsdf), weight);
@@ -309,7 +308,8 @@ ccl_device_noinline void subsurface_scatter_multi_setup(
         int hit,
         ShaderData *sd,
         ccl_addr_space PathState *state,
-        const ShaderClosure *sc)
+        ClosureType type,
+        float roughness)
 {
 #ifdef __SPLIT_KERNEL__
 	Ray ray_object = ss_isect->ray;
@@ -332,7 +332,7 @@ ccl_device_noinline void subsurface_scatter_multi_setup(
 	subsurface_color_bump_blur(kg, sd, state, &weight, &N);
 
 	/* Setup diffuse BSDF. */
-	subsurface_scatter_setup_diffuse_bsdf(kg, sd, sc, weight, N);
+	subsurface_scatter_setup_diffuse_bsdf(kg, sd, type, roughness, weight, N);
 }
 
 /* Random walk subsurface scattering.
diff --git a/intern/cycles/kernel/split/kernel_subsurface_scatter.h b/intern/cycles/kernel/split/kernel_subsurface_scatter.h
index af0303d8608..c51246fbc90 100644
--- a/intern/cycles/kernel/split/kernel_subsurface_scatter.h
+++ b/intern/cycles/kernel/split/kernel_subsurface_scatter.h
@@ -110,13 +110,18 @@ ccl_device_noinline bool kernel_split_branched_path_subsurface_indirect_light_it
 				*bssrdf_sd = *sd; /* note: copy happens each iteration of inner loop, this is
 				                   * important as the indirect path will write into bssrdf_sd */
 
+				Bssrdf *bssrdf = (Bssrdf *)sc;
+				ClosureType bssrdf_type = sc->type;
+				float bssrdf_roughness = bssrdf->roughness;
+
 				LocalIntersection ss_isect_private = *ss_isect;
 				subsurface_scatter_multi_setup(kg,
 				                               &ss_isect_private,
 				                               hit,
 				                               bssrdf_sd,
 				                               hit_state,
-				                               sc);
+				                               bssrdf_type,
+				                               bssrdf_roughness);
 				*ss_isect = ss_isect_private;
 
 #ifdef __VOLUME__