Cycles / Ray Depth:

* Added a Ray Depth output to the Light Path node, which gives the user access to the current bounce.
This can be used to limit the maximum ray bounce on a per shader basis. Another use case is to restrict light influence with this, to have a lamp only contribute to the direct lighting. 

http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Cycles/Nodes/More#Light_Path

This is part of my GSoC 2013 project. SVN merge of r58091 and r58772 from soc-2013-dingto. 

1 files changed, 10 insertions, 10 deletions

diff --git a/intern/cycles/kernel/kernel_emission.h b/intern/cycles/kernel/kernel_emission.h
index 77dc59d2691..a6bd3ed2850 100644
--- a/intern/cycles/kernel/kernel_emission.h
+++ b/intern/cycles/kernel/kernel_emission.h
@@ -21,7 +21,7 @@ CCL_NAMESPACE_BEGIN
 /* Direction Emission */
 
 __device_noinline float3 direct_emissive_eval(KernelGlobals *kg, float rando,
-	LightSample *ls, float u, float v, float3 I, differential3 dI, float t, float time)
+	LightSample *ls, float u, float v, float3 I, differential3 dI, float t, float time, int bounce)
 {
 	/* setup shading at emitter */
 	ShaderData sd;
@@ -41,7 +41,7 @@ __device_noinline float3 direct_emissive_eval(KernelGlobals *kg, float rando,
 #ifdef __CAMERA_MOTION__
 		ray.time = time;
 #endif
-		shader_setup_from_background(kg, &sd, &ray);
+		shader_setup_from_background(kg, &sd, &ray, bounce+1);
 		eval = shader_eval_background(kg, &sd, 0, SHADER_CONTEXT_EMISSION);
 	}
 	else
@@ -49,10 +49,10 @@ __device_noinline float3 direct_emissive_eval(KernelGlobals *kg, float rando,
 	{
 #ifdef __HAIR__
 		if(ls->type == LIGHT_STRAND)
-			shader_setup_from_sample(kg, &sd, ls->P, ls->Ng, I, ls->shader, ls->object, ls->prim, u, v, t, time, ls->prim);
+			shader_setup_from_sample(kg, &sd, ls->P, ls->Ng, I, ls->shader, ls->object, ls->prim, u, v, t, time, bounce+1, ls->prim);
 		else
 #endif
-			shader_setup_from_sample(kg, &sd, ls->P, ls->Ng, I, ls->shader, ls->object, ls->prim, u, v, t, time, ~0);
+			shader_setup_from_sample(kg, &sd, ls->P, ls->Ng, I, ls->shader, ls->object, ls->prim, u, v, t, time, bounce+1, ~0);
 
 		ls->Ng = sd.Ng;
 
@@ -74,7 +74,7 @@ __device_noinline float3 direct_emissive_eval(KernelGlobals *kg, float rando,
 
 __device_noinline bool direct_emission(KernelGlobals *kg, ShaderData *sd, int lindex,
 	float randt, float rando, float randu, float randv, Ray *ray, BsdfEval *eval,
-	bool *is_lamp)
+	bool *is_lamp, int bounce)
 {
 	LightSample ls;
 
@@ -97,7 +97,7 @@ __device_noinline bool direct_emission(KernelGlobals *kg, ShaderData *sd, int li
 	differential3 dD = differential3_zero();
 
 	/* evaluate closure */
-	float3 light_eval = direct_emissive_eval(kg, rando, &ls, randu, randv, -ls.D, dD, ls.t, sd->time);
+	float3 light_eval = direct_emissive_eval(kg, rando, &ls, randu, randv, -ls.D, dD, ls.t, sd->time, bounce);
 
 	if(is_zero(light_eval))
 		return false;
@@ -185,7 +185,7 @@ __device_noinline float3 indirect_primitive_emission(KernelGlobals *kg, ShaderDa
 
 /* Indirect Lamp Emission */
 
-__device_noinline bool indirect_lamp_emission(KernelGlobals *kg, Ray *ray, int path_flag, float bsdf_pdf, float randt, float3 *emission)
+__device_noinline bool indirect_lamp_emission(KernelGlobals *kg, Ray *ray, int path_flag, float bsdf_pdf, float randt, float3 *emission, int bounce)
 {
 	LightSample ls;
 	int lamp = lamp_light_eval_sample(kg, randt);
@@ -209,7 +209,7 @@ __device_noinline bool indirect_lamp_emission(KernelGlobals *kg, Ray *ray, int p
 	/* todo: missing texture coordinates */
 	float u = 0.0f;
 	float v = 0.0f;
-	float3 L = direct_emissive_eval(kg, 0.0f, &ls, u, v, -ray->D, ray->dD, ls.t, ray->time);
+	float3 L = direct_emissive_eval(kg, 0.0f, &ls, u, v, -ray->D, ray->dD, ls.t, ray->time, bounce);
 
 	if(!(path_flag & PATH_RAY_MIS_SKIP)) {
 		/* multiple importance sampling, get regular light pdf,
@@ -224,7 +224,7 @@ __device_noinline bool indirect_lamp_emission(KernelGlobals *kg, Ray *ray, int p
 
 /* Indirect Background */
 
-__device_noinline float3 indirect_background(KernelGlobals *kg, Ray *ray, int path_flag, float bsdf_pdf)
+__device_noinline float3 indirect_background(KernelGlobals *kg, Ray *ray, int path_flag, float bsdf_pdf, int bounce)
 {
 #ifdef __BACKGROUND__
 	int shader = kernel_data.background.shader;
@@ -240,7 +240,7 @@ __device_noinline float3 indirect_background(KernelGlobals *kg, Ray *ray, int pa
 
 	/* evaluate background closure */
 	ShaderData sd;
-	shader_setup_from_background(kg, &sd, ray);
+	shader_setup_from_background(kg, &sd, ray, bounce+1);
 
 	float3 L = shader_eval_background(kg, &sd, path_flag, SHADER_CONTEXT_EMISSION);