Fix T40987: Distant Lamps have no influence on Volumes.

Differential Revision: https://developer.blender.org/D639

3 files changed, 18 insertions, 39 deletions

diff --git a/intern/cycles/kernel/kernel_light.h b/intern/cycles/kernel/kernel_light.h
index 0adf9ed4666..ac432d3fe04 100644
--- a/intern/cycles/kernel/kernel_light.h
+++ b/intern/cycles/kernel/kernel_light.h
@@ -208,8 +208,8 @@ ccl_device float lamp_light_pdf(KernelGlobals *kg, const float3 Ng, const float3
 	return t*t/cos_pi;
 }
 
-ccl_device bool lamp_light_sample(KernelGlobals *kg, int lamp,
-	float randu, float randv, float3 P, LightSample *ls, bool for_volume)
+ccl_device void lamp_light_sample(KernelGlobals *kg, int lamp,
+	float randu, float randv, float3 P, LightSample *ls)
 {
 	float4 data0 = kernel_tex_fetch(__light_data, lamp*LIGHT_SIZE + 0);
 	float4 data1 = kernel_tex_fetch(__light_data, lamp*LIGHT_SIZE + 1);
@@ -224,11 +224,6 @@ ccl_device bool lamp_light_sample(KernelGlobals *kg, int lamp,
 	ls->v = randv;
 
 	if(type == LIGHT_DISTANT) {
-#ifdef __VOLUME__
-		if(for_volume)
-			return false;
-#endif
-
 		/* distant light */
 		float3 lightD = make_float3(data0.y, data0.z, data0.w);
 		float3 D = lightD;
@@ -249,11 +244,6 @@ ccl_device bool lamp_light_sample(KernelGlobals *kg, int lamp,
 	}
 #ifdef __BACKGROUND_MIS__
 	else if(type == LIGHT_BACKGROUND) {
-#ifdef __VOLUME__
-		if(for_volume)
-			return false;
-#endif
-
 		/* infinite area light (e.g. light dome or env light) */
 		float3 D = background_light_sample(kg, randu, randv, &ls->pdf);
 
@@ -309,8 +299,6 @@ ccl_device bool lamp_light_sample(KernelGlobals *kg, int lamp,
 		ls->eval_fac *= kernel_data.integrator.inv_pdf_lights;
 		ls->pdf *= lamp_light_pdf(kg, ls->Ng, -ls->D, ls->t);
 	}
-
-	return true;
 }
 
 ccl_device bool lamp_light_eval(KernelGlobals *kg, int lamp, float3 P, float3 D, float t, LightSample *ls)
@@ -526,7 +514,7 @@ ccl_device int light_distribution_sample(KernelGlobals *kg, float randt)
 
 /* Generic Light */
 
-ccl_device bool light_sample(KernelGlobals *kg, float randt, float randu, float randv, float time, float3 P, LightSample *ls, bool for_volume)
+ccl_device void light_sample(KernelGlobals *kg, float randt, float randu, float randv, float time, float3 P, LightSample *ls)
 {
 	/* sample index */
 	int index = light_distribution_sample(kg, randt);
@@ -545,12 +533,10 @@ ccl_device bool light_sample(KernelGlobals *kg, float randt, float randu, float
 		ls->D = normalize_len(ls->P - P, &ls->t);
 		ls->pdf = triangle_light_pdf(kg, ls->Ng, -ls->D, ls->t);
 		ls->shader |= shader_flag;
-
-		return true;
 	}
 	else {
 		int lamp = -prim-1;
-		return lamp_light_sample(kg, lamp, randu, randv, P, ls, for_volume);
+		lamp_light_sample(kg, lamp, randu, randv, P, ls);
 	}
 }
 
@@ -560,9 +546,9 @@ ccl_device int light_select_num_samples(KernelGlobals *kg, int index)
 	return __float_as_int(data3.x);
 }
 
-ccl_device bool light_select(KernelGlobals *kg, int index, float randu, float randv, float3 P, LightSample *ls, bool for_volume)
+ccl_device void light_select(KernelGlobals *kg, int index, float randu, float randv, float3 P, LightSample *ls)
 {
-	return lamp_light_sample(kg, index, randu, randv, P, ls, for_volume);
+	lamp_light_sample(kg, index, randu, randv, P, ls);
 }
 
 ccl_device int lamp_light_eval_sample(KernelGlobals *kg, float randt)
diff --git a/intern/cycles/kernel/kernel_path_surface.h b/intern/cycles/kernel/kernel_path_surface.h
index 7700abfbdae..81526b0ba7a 100644
--- a/intern/cycles/kernel/kernel_path_surface.h
+++ b/intern/cycles/kernel/kernel_path_surface.h
@@ -50,7 +50,7 @@ ccl_device void kernel_branched_path_surface_connect_light(KernelGlobals *kg, RN
 				path_branched_rng_2D(kg, &lamp_rng, state, j, num_samples, PRNG_LIGHT_U, &light_u, &light_v);
 
 				LightSample ls;
-				light_select(kg, i, light_u, light_v, sd->P, &ls, false);
+				light_select(kg, i, light_u, light_v, sd->P, &ls);
 
 				if(direct_emission(kg, sd, &ls, &light_ray, &L_light, &is_lamp, state->bounce, state->transparent_bounce)) {
 					/* trace shadow ray */
@@ -82,7 +82,7 @@ ccl_device void kernel_branched_path_surface_connect_light(KernelGlobals *kg, RN
 					light_t = 0.5f*light_t;
 
 				LightSample ls;
-				light_sample(kg, light_t, light_u, light_v, sd->time, sd->P, &ls, false);
+				light_sample(kg, light_t, light_u, light_v, sd->time, sd->P, &ls);
 
 				if(direct_emission(kg, sd, &ls, &light_ray, &L_light, &is_lamp, state->bounce, state->transparent_bounce)) {
 					/* trace shadow ray */
@@ -103,7 +103,7 @@ ccl_device void kernel_branched_path_surface_connect_light(KernelGlobals *kg, RN
 		path_state_rng_2D(kg, rng, state, PRNG_LIGHT_U, &light_u, &light_v);
 
 		LightSample ls;
-		light_sample(kg, light_t, light_u, light_v, sd->time, sd->P, &ls, false);
+		light_sample(kg, light_t, light_u, light_v, sd->time, sd->P, &ls);
 
 		/* sample random light */
 		if(direct_emission(kg, sd, &ls, &light_ray, &L_light, &is_lamp, state->bounce, state->transparent_bounce)) {
@@ -200,7 +200,7 @@ ccl_device_inline void kernel_path_surface_connect_light(KernelGlobals *kg, RNG
 #endif
 
 	LightSample ls;
-	light_sample(kg, light_t, light_u, light_v, sd->time, sd->P, &ls, false);
+	light_sample(kg, light_t, light_u, light_v, sd->time, sd->P, &ls);
 
 	if(direct_emission(kg, sd, &ls, &light_ray, &L_light, &is_lamp, state->bounce, state->transparent_bounce)) {
 		/* trace shadow ray */
diff --git a/intern/cycles/kernel/kernel_path_volume.h b/intern/cycles/kernel/kernel_path_volume.h
index 8453b79de45..b4917f9a3ae 100644
--- a/intern/cycles/kernel/kernel_path_volume.h
+++ b/intern/cycles/kernel/kernel_path_volume.h
@@ -41,9 +41,8 @@ ccl_device void kernel_path_volume_connect_light(KernelGlobals *kg, RNG *rng,
 	light_ray.time = sd->time;
 #endif
 
-	if(!light_sample(kg, light_t, light_u, light_v, sd->time, sd->P, &ls, true))
-		return;
-	else if(ls.pdf == 0.0f)
+	light_sample(kg, light_t, light_u, light_v, sd->time, sd->P, &ls);
+	if(ls.pdf == 0.0f)
 		return;
 	
 	if(direct_emission(kg, sd, &ls, &light_ray, &L_light, &is_lamp, state->bounce, state->transparent_bounce)) {
@@ -135,8 +134,7 @@ ccl_device void kernel_branched_path_volume_connect_light(KernelGlobals *kg, RNG
 				path_branched_rng_2D(kg, &lamp_rng, state, j, num_samples, PRNG_LIGHT_U, &light_u, &light_v);
 
 				LightSample ls;
-				if(!light_select(kg, i, light_u, light_v, ray->P, &ls, true))
-					continue;
+				light_select(kg, i, light_u, light_v, ray->P, &ls);		
 
 				float3 tp = throughput;
 
@@ -152,8 +150,7 @@ ccl_device void kernel_branched_path_volume_connect_light(KernelGlobals *kg, RNG
 						continue;
 
 					/* todo: split up light_sample so we don't have to call it again with new position */
-					if(!light_select(kg, i, light_u, light_v, sd->P, &ls, true))
-						continue;
+					light_select(kg, i, light_u, light_v, sd->P, &ls);
 				}
 
 				if(ls.pdf == 0.0f)
@@ -190,8 +187,7 @@ ccl_device void kernel_branched_path_volume_connect_light(KernelGlobals *kg, RNG
 					light_t = 0.5f*light_t;
 
 				LightSample ls;
-				if(!light_sample(kg, light_t, light_u, light_v, sd->time, ray->P, &ls, true))
-					continue;
+				light_sample(kg, light_t, light_u, light_v, sd->time, ray->P, &ls);
 
 				float3 tp = throughput;
 
@@ -207,8 +203,7 @@ ccl_device void kernel_branched_path_volume_connect_light(KernelGlobals *kg, RNG
 						continue;
 
 					/* todo: split up light_sample so we don't have to call it again with new position */
-					if(!light_sample(kg, light_t, light_u, light_v, sd->time, sd->P, &ls, true))
-						continue;
+					light_sample(kg, light_t, light_u, light_v, sd->time, sd->P, &ls);
 				}
 
 				if(ls.pdf == 0.0f)
@@ -233,8 +228,7 @@ ccl_device void kernel_branched_path_volume_connect_light(KernelGlobals *kg, RNG
 		path_state_rng_2D(kg, rng, state, PRNG_LIGHT_U, &light_u, &light_v);
 
 		LightSample ls;
-		if(!light_sample(kg, light_t, light_u, light_v, sd->time, ray->P, &ls, true))
-			return;
+		light_sample(kg, light_t, light_u, light_v, sd->time, ray->P, &ls);
 
 		float3 tp = throughput;
 
@@ -250,8 +244,7 @@ ccl_device void kernel_branched_path_volume_connect_light(KernelGlobals *kg, RNG
 				return;
 
 			/* todo: split up light_sample so we don't have to call it again with new position */
-			if(!light_sample(kg, light_t, light_u, light_v, sd->time, sd->P, &ls, true))
-				return;
+			light_sample(kg, light_t, light_u, light_v, sd->time, sd->P, &ls);
 		}
 
 		if(ls.pdf == 0.0f)