Cycles: Implement texture coordinates for Point, Spot and Area Lamps

When using the Normal output of the Texture Coordinate node on Point and Spot lamps, the coordinates now depend on the rotation of the lamp.
On Area lamps, the Parametric output of the Geometry node now returns UV coordinates on the area lamp.

Credit for the Area lamp part goes to Stefan Werner (from D1995).

8 files changed, 81 insertions, 15 deletions

diff --git a/intern/cycles/kernel/geom/geom_object.h b/intern/cycles/kernel/geom/geom_object.h
index 32900f7f27a..6b42f66b0d5 100644
--- a/intern/cycles/kernel/geom/geom_object.h
+++ b/intern/cycles/kernel/geom/geom_object.h
@@ -55,6 +55,21 @@ ccl_device_inline Transform object_fetch_transform(KernelGlobals *kg, int object
 	return tfm;
 }
 
+/* Lamp to world space transformation */
+
+ccl_device_inline Transform lamp_fetch_transform(KernelGlobals *kg, int lamp, bool inverse)
+{
+	int offset = lamp*LIGHT_SIZE + (inverse? 8 : 5);
+
+	Transform tfm;
+	tfm.x = kernel_tex_fetch(__light_data, offset + 0);
+	tfm.y = kernel_tex_fetch(__light_data, offset + 1);
+	tfm.z = kernel_tex_fetch(__light_data, offset + 2);
+	tfm.w = make_float4(0.0f, 0.0f, 0.0f, 1.0f);
+
+	return tfm;
+}
+
 /* Object to world space transformation for motion vectors */
 
 ccl_device_inline Transform object_fetch_vector_transform(KernelGlobals *kg, int object, enum ObjectVectorTransform type)
diff --git a/intern/cycles/kernel/kernel_bake.h b/intern/cycles/kernel/kernel_bake.h
index fd9207fd69f..84575d35d7f 100644
--- a/intern/cycles/kernel/kernel_bake.h
+++ b/intern/cycles/kernel/kernel_bake.h
@@ -320,7 +320,8 @@ ccl_device void kernel_bake_evaluate(KernelGlobals *kg, ccl_global uint4 *input,
 	                         P, Ng, Ng,
 	                         shader, object, prim,
 	                         u, v, 1.0f, 0.5f,
-	                         !(kernel_tex_fetch(__object_flag, object) & SD_TRANSFORM_APPLIED));
+	                         !(kernel_tex_fetch(__object_flag, object) & SD_TRANSFORM_APPLIED),
+	                         LAMP_NONE);
 	sd.I = sd.N;
 
 	/* update differentials */
diff --git a/intern/cycles/kernel/kernel_emission.h b/intern/cycles/kernel/kernel_emission.h
index ac498ba3592..9e4a631b998 100644
--- a/intern/cycles/kernel/kernel_emission.h
+++ b/intern/cycles/kernel/kernel_emission.h
@@ -65,7 +65,7 @@ ccl_device_noinline float3 direct_emissive_eval(KernelGlobals *kg,
 		shader_setup_from_sample(kg, emission_sd,
 		                         ls->P, ls->Ng, I,
 		                         ls->shader, ls->object, ls->prim,
-		                         ls->u, ls->v, t, time, false);
+		                         ls->u, ls->v, t, time, false, ls->lamp);
 
 		ls->Ng = ccl_fetch(emission_sd, Ng);
 
diff --git a/intern/cycles/kernel/kernel_light.h b/intern/cycles/kernel/kernel_light.h
index fffa9afb342..d4cc36d1495 100644
--- a/intern/cycles/kernel/kernel_light.h
+++ b/intern/cycles/kernel/kernel_light.h
@@ -297,7 +297,7 @@ ccl_device_inline float background_portal_pdf(KernelGlobals *kg,
 		float3 axisu = make_float3(data1.y, data1.z, data1.w);
 		float3 axisv = make_float3(data2.y, data2.z, data2.w);
 
-		if(!ray_quad_intersect(P, direction, 1e-4f, FLT_MAX, lightpos, axisu, axisv, dir, NULL, NULL))
+		if(!ray_quad_intersect(P, direction, 1e-4f, FLT_MAX, lightpos, axisu, axisv, dir, NULL, NULL, NULL, NULL))
 			continue;
 
 		portal_pdf += area_light_sample(P, &lightpos, axisu, axisv, 0.0f, 0.0f, false);
@@ -585,6 +585,10 @@ ccl_device_inline bool lamp_light_sample(KernelGlobals *kg,
 					return false;
 				}
 			}
+			float2 uv = map_to_sphere(ls->Ng);
+			ls->u = uv.x;
+			ls->v = uv.y;
+
 			ls->pdf *= lamp_light_pdf(kg, ls->Ng, -ls->D, ls->t);
 		}
 		else {
@@ -600,11 +604,16 @@ ccl_device_inline bool lamp_light_sample(KernelGlobals *kg,
 				return false;
 			}
 
+			float3 inplane = ls->P;
 			ls->pdf = area_light_sample(P, &ls->P,
 			                          axisu, axisv,
 			                          randu, randv,
 			                          true);
 
+			inplane = ls->P - inplane;
+			ls->u = dot(inplane, axisu) * (1.0f / dot(axisu, axisu)) + 0.5f;
+			ls->v = dot(inplane, axisv) * (1.0f / dot(axisv, axisv)) + 0.5f;
+
 			ls->Ng = D;
 			ls->D = normalize_len(ls->P - P, &ls->t);
 
@@ -706,6 +715,9 @@ ccl_device bool lamp_light_eval(KernelGlobals *kg, int lamp, float3 P, float3 D,
 			if(ls->eval_fac == 0.0f)
 				return false;
 		}
+		float2 uv = map_to_sphere(ls->Ng);
+		ls->u = uv.x;
+		ls->v = uv.y;
 
 		/* compute pdf */
 		if(ls->t != FLT_MAX)
@@ -730,8 +742,10 @@ ccl_device bool lamp_light_eval(KernelGlobals *kg, int lamp, float3 P, float3 D,
 
 		float3 light_P = make_float3(data0.y, data0.z, data0.w);
 
-		if(!ray_quad_intersect(P, D, 0.0f, t,
-		                       light_P, axisu, axisv, Ng, &ls->P, &ls->t))
+		if(!ray_quad_intersect(P, D, 0.0f, t, light_P,
+		                       axisu, axisv, Ng,
+		                       &ls->P, &ls->t,
+		                       &ls->u, &ls->v))
 		{
 			return false;
 		}
@@ -887,4 +901,3 @@ ccl_device int light_select_num_samples(KernelGlobals *kg, int index)
 }
 
 CCL_NAMESPACE_END
-
diff --git a/intern/cycles/kernel/kernel_shader.h b/intern/cycles/kernel/kernel_shader.h
index 3e098c922dc..6480975a84d 100644
--- a/intern/cycles/kernel/kernel_shader.h
+++ b/intern/cycles/kernel/kernel_shader.h
@@ -242,7 +242,8 @@ ccl_device_inline void shader_setup_from_sample(KernelGlobals *kg,
                                                 int shader, int object, int prim,
                                                 float u, float v, float t,
                                                 float time,
-                                                bool object_space)
+                                                bool object_space,
+                                                int lamp)
 {
 	/* vectors */
 	ccl_fetch(sd, P) = P;
@@ -250,7 +251,12 @@ ccl_device_inline void shader_setup_from_sample(KernelGlobals *kg,
 	ccl_fetch(sd, Ng) = Ng;
 	ccl_fetch(sd, I) = I;
 	ccl_fetch(sd, shader) = shader;
-	ccl_fetch(sd, type) = (prim == PRIM_NONE)? PRIMITIVE_NONE: PRIMITIVE_TRIANGLE;
+	if(prim != PRIM_NONE)
+		ccl_fetch(sd, type) = PRIMITIVE_TRIANGLE;
+	else if(lamp != LAMP_NONE)
+		ccl_fetch(sd, type) = PRIMITIVE_LAMP;
+	else
+		ccl_fetch(sd, type) = PRIMITIVE_NONE;
 
 	/* primitive */
 #ifdef __INSTANCING__
@@ -270,11 +276,15 @@ ccl_device_inline void shader_setup_from_sample(KernelGlobals *kg,
 
 #ifdef __OBJECT_MOTION__
 		shader_setup_object_transforms(kg, sd, time);
+#else
+	}
+	else if(lamp != LAMP_NONE) {
+		ccl_fetch(sd, ob_tfm)  = lamp_fetch_transform(kg, lamp, false);
+		ccl_fetch(sd, ob_itfm) = lamp_fetch_transform(kg, lamp, true);
 	}
 
+#ifdef __OBJECT_MOTION__
 	ccl_fetch(sd, time) = time;
-#else
-	}
 #endif
 
 	/* transform into world space */
@@ -357,7 +367,8 @@ ccl_device void shader_setup_from_displace(KernelGlobals *kg, ShaderData *sd,
 	                         P, Ng, I,
 	                         shader, object, prim,
 	                         u, v, 0.0f, 0.5f,
-	                         !(kernel_tex_fetch(__object_flag, object) & SD_TRANSFORM_APPLIED));
+	                         !(kernel_tex_fetch(__object_flag, object) & SD_TRANSFORM_APPLIED),
+	                         LAMP_NONE);
 }
 
 /* ShaderData setup from ray into background */
diff --git a/intern/cycles/kernel/kernel_types.h b/intern/cycles/kernel/kernel_types.h
index 734b4462a91..91b86618745 100644
--- a/intern/cycles/kernel/kernel_types.h
+++ b/intern/cycles/kernel/kernel_types.h
@@ -37,7 +37,7 @@ CCL_NAMESPACE_BEGIN
 /* constants */
 #define OBJECT_SIZE 		12
 #define OBJECT_VECTOR_SIZE	6
-#define LIGHT_SIZE			5
+#define LIGHT_SIZE		11
 #define FILTER_TABLE_SIZE	1024
 #define RAMP_TABLE_SIZE		256
 #define SHUTTER_TABLE_SIZE		256
@@ -552,6 +552,8 @@ typedef enum PrimitiveType {
 	PRIMITIVE_MOTION_TRIANGLE = 2,
 	PRIMITIVE_CURVE = 4,
 	PRIMITIVE_MOTION_CURVE = 8,
+	/* Lamp primitive is not included below on purpose, since it is no real traceable primitive */
+	PRIMITIVE_LAMP = 16,
 
 	PRIMITIVE_ALL_TRIANGLE = (PRIMITIVE_TRIANGLE|PRIMITIVE_MOTION_TRIANGLE),
 	PRIMITIVE_ALL_CURVE = (PRIMITIVE_CURVE|PRIMITIVE_MOTION_CURVE),
diff --git a/intern/cycles/kernel/osl/osl_services.cpp b/intern/cycles/kernel/osl/osl_services.cpp
index 0f3edcb7eaa..26543862b80 100644
--- a/intern/cycles/kernel/osl/osl_services.cpp
+++ b/intern/cycles/kernel/osl/osl_services.cpp
@@ -168,6 +168,12 @@ bool OSLRenderServices::get_matrix(OSL::ShaderGlobals *sg, OSL::Matrix44 &result
 
 			return true;
 		}
+		else if(sd->type == PRIMITIVE_LAMP) {
+			Transform tfm = transform_transpose(sd->ob_tfm);
+			COPY_MATRIX44(&result, &tfm);
+
+			return true;
+		}
 	}
 
 	return false;
@@ -198,6 +204,12 @@ bool OSLRenderServices::get_inverse_matrix(OSL::ShaderGlobals *sg, OSL::Matrix44
 
 			return true;
 		}
+		else if(sd->type == PRIMITIVE_LAMP) {
+			Transform tfm = transform_transpose(sd->ob_itfm);
+			COPY_MATRIX44(&result, &tfm);
+
+			return true;
+		}
 	}
 
 	return false;
@@ -287,6 +299,12 @@ bool OSLRenderServices::get_matrix(OSL::ShaderGlobals *sg, OSL::Matrix44 &result
 
 			return true;
 		}
+		else if(sd->type == PRIMITIVE_LAMP) {
+			Transform tfm = transform_transpose(sd->ob_tfm);
+			COPY_MATRIX44(&result, &tfm);
+
+			return true;
+		}
 	}
 
 	return false;
@@ -312,6 +330,12 @@ bool OSLRenderServices::get_inverse_matrix(OSL::ShaderGlobals *sg, OSL::Matrix44
 
 			return true;
 		}
+		else if(sd->type == PRIMITIVE_LAMP) {
+			Transform tfm = transform_transpose(sd->ob_itfm);
+			COPY_MATRIX44(&result, &tfm);
+
+			return true;
+		}
 	}
 
 	return false;
diff --git a/intern/cycles/kernel/svm/svm_tex_coord.h b/intern/cycles/kernel/svm/svm_tex_coord.h
index 6ea2539c543..6c3394adbce 100644
--- a/intern/cycles/kernel/svm/svm_tex_coord.h
+++ b/intern/cycles/kernel/svm/svm_tex_coord.h
@@ -49,7 +49,7 @@ ccl_device void svm_node_tex_coord(KernelGlobals *kg,
 		}
 		case NODE_TEXCO_NORMAL: {
 			data = ccl_fetch(sd, N);
-			if(ccl_fetch(sd, object) != OBJECT_NONE)
+			if((ccl_fetch(sd, object) != OBJECT_NONE) || (ccl_fetch(sd, type) == PRIMITIVE_LAMP))
 				object_inverse_normal_transform(kg, sd, &data);
 			break;
 		}
@@ -131,7 +131,7 @@ ccl_device void svm_node_tex_coord_bump_dx(KernelGlobals *kg,
 		}
 		case NODE_TEXCO_NORMAL: {
 			data = ccl_fetch(sd, N);
-			if(ccl_fetch(sd, object) != OBJECT_NONE)
+			if((ccl_fetch(sd, object) != OBJECT_NONE) || (ccl_fetch(sd, type) == PRIMITIVE_LAMP))
 				object_inverse_normal_transform(kg, sd, &data);
 			break;
 		}
@@ -216,7 +216,7 @@ ccl_device void svm_node_tex_coord_bump_dy(KernelGlobals *kg,
 		}
 		case NODE_TEXCO_NORMAL: {
 			data = ccl_fetch(sd, N);
-			if(ccl_fetch(sd, object) != OBJECT_NONE)
+			if((ccl_fetch(sd, object) != OBJECT_NONE) || (ccl_fetch(sd, type) == PRIMITIVE_LAMP))
 				object_inverse_normal_transform(kg, sd, &data);
 			break;
 		}