Blender Internal: Add "Lamp Data" shader node that allows shaders to acquire information such as light vector from specified Lamp.

For now this provides the following outputs:

- Color
- Light Vector
- Distance
- Shadow
- Visibility Factor

Note: Color output is multiplied by the lamp energy.  Multiplication of
color*max(dot(light_vector,normal_vector),0)*shadow*visibility_factor
produces the exact same result as the Lambert shader.

Many thanks to Brecht for code review and discussion!

release/scripts/startup/nodeitems_builtins.py

@@ -111,6 +111,7 @@ shader_node_categories = [
     ShaderOldNodeCategory("SH_INPUT", "Input", items=[
         NodeItem("ShaderNodeMaterial"),
         NodeItem("ShaderNodeCameraData"),
+        NodeItem("ShaderNodeLampData"),
         NodeItem("ShaderNodeValue"),
         NodeItem("ShaderNodeRGB"),
         NodeItem("ShaderNodeTexture"),

source/blender/blenkernel/BKE_node.h

@@ -740,6 +740,7 @@ struct ShadeResult;
 #define SH_NODE_SEPHSV					183
 #define SH_NODE_COMBHSV					184
 #define SH_NODE_BSDF_HAIR				185
+#define SH_NODE_LAMP					186
 
 /* custom defines options for Material node */
 #define SH_NODE_MAT_DIFF   1

source/blender/blenkernel/intern/node.c

@@ -3435,6 +3435,7 @@ static void registerShaderNodes(void)
 	register_node_type_sh_output();
 	register_node_type_sh_material();
 	register_node_type_sh_camera();
+	register_node_type_sh_lamp();
 	register_node_type_sh_gamma();
 	register_node_type_sh_brightcontrast();
 	register_node_type_sh_value();

source/blender/editors/space_node/drawnode.c

@@ -753,6 +753,11 @@ static void node_shader_buts_geometry(uiLayout *layout, bContext *C, PointerRNA
 	}
 }
 
+static void node_shader_buts_lamp(uiLayout *layout, bContext *UNUSED(C), PointerRNA *ptr)
+{
+	uiItemR(layout, ptr, "lamp_object", 0, IFACE_("Lamp Object"), ICON_NONE);
+}
+
 static void node_shader_buts_attribute(uiLayout *layout, bContext *UNUSED(C), PointerRNA *ptr)
 {
 	uiItemR(layout, ptr, "attribute_name", 0, IFACE_("Name"), ICON_NONE);
@@ -1002,6 +1007,9 @@ static void node_shader_set_butfunc(bNodeType *ntype)
 		case SH_NODE_GEOMETRY:
 			ntype->draw_buttons = node_shader_buts_geometry;
 			break;
+		case SH_NODE_LAMP:
+			ntype->draw_buttons = node_shader_buts_lamp;
+			break;
 		case SH_NODE_ATTRIBUTE:
 			ntype->draw_buttons = node_shader_buts_attribute;
 			break;

source/blender/gpu/GPU_material.h

@@ -133,6 +133,7 @@ void GPU_material_bind(GPUMaterial *material, int oblay, int viewlay, double tim
 void GPU_material_bind_uniforms(GPUMaterial *material, float obmat[4][4], float obcol[4], float autobumpscale);
 void GPU_material_unbind(GPUMaterial *material);
 int GPU_material_bound(GPUMaterial *material);
+struct Scene *GPU_material_scene(GPUMaterial *material);
 
 void GPU_material_vertex_attributes(GPUMaterial *material,
 	struct GPUVertexAttribs *attrib);
@@ -244,6 +245,7 @@ void GPU_lamp_update_colors(GPULamp *lamp, float r, float g, float b, float ener
 void GPU_lamp_update_distance(GPULamp *lamp, float distance, float att1, float att2);
 void GPU_lamp_update_spot(GPULamp *lamp, float spotsize, float spotblend);
 int GPU_lamp_shadow_layer(GPULamp *lamp);
+GPUNodeLink *GPU_lamp_get_data(GPUMaterial *mat, GPULamp *lamp, GPUNodeLink **col, GPUNodeLink **lv, GPUNodeLink **dist, GPUNodeLink **shadow);
 
 #ifdef __cplusplus
 }

source/blender/gpu/intern/gpu_material.c

@@ -355,6 +355,11 @@ int GPU_material_bound(GPUMaterial *material)
 	return material->bound;
 }
 
+Scene *GPU_material_scene(GPUMaterial *material)
+{
+	return material->scene;
+}
+
 void GPU_material_vertex_attributes(GPUMaterial *material, GPUVertexAttribs *attribs)
 {
 	*attribs = material->attribs;
@@ -1953,6 +1958,48 @@ int GPU_lamp_shadow_layer(GPULamp *lamp)
 		return -1;
 }
 
+GPUNodeLink *GPU_lamp_get_data(GPUMaterial *mat, GPULamp *lamp, GPUNodeLink **col, GPUNodeLink **lv, GPUNodeLink **dist, GPUNodeLink **shadow)
+{
+	GPUNodeLink *visifac;
+
+	*col = GPU_dynamic_uniform(lamp->dyncol, GPU_DYNAMIC_LAMP_DYNCOL, lamp->ob);
+	visifac = lamp_get_visibility(mat, lamp, lv, dist);
+	shade_light_textures(mat, lamp, col);
+
+	if (GPU_lamp_has_shadow_buffer(lamp)) {
+		GPUNodeLink *vn, *inp;
+
+		GPU_link(mat, "shade_norm", GPU_builtin(GPU_VIEW_NORMAL), &vn);
+		GPU_link(mat, "shade_inp", vn, *lv, &inp);
+		mat->dynproperty |= DYN_LAMP_PERSMAT;
+
+		if (lamp->la->shadowmap_type == LA_SHADMAP_VARIANCE) {
+			GPU_link(mat, "shadows_only_vsm",
+				 GPU_builtin(GPU_VIEW_POSITION),
+				 GPU_dynamic_texture(lamp->tex, GPU_DYNAMIC_SAMPLER_2DSHADOW, lamp->ob),
+				 GPU_dynamic_uniform((float*)lamp->dynpersmat, GPU_DYNAMIC_LAMP_DYNPERSMAT, lamp->ob),
+				 GPU_uniform(&lamp->bias), GPU_uniform(&lamp->la->bleedbias),
+				 GPU_uniform(lamp->shadow_color), inp, shadow);
+		}
+		else {
+			GPU_link(mat, "shadows_only",
+				 GPU_builtin(GPU_VIEW_POSITION),
+				 GPU_dynamic_texture(lamp->tex, GPU_DYNAMIC_SAMPLER_2DSHADOW, lamp->ob),
+				 GPU_dynamic_uniform((float*)lamp->dynpersmat, GPU_DYNAMIC_LAMP_DYNPERSMAT, lamp->ob),
+				 GPU_uniform(&lamp->bias), GPU_uniform(lamp->shadow_color), inp, shadow);
+		}
+	}
+	else {
+		GPU_link(mat, "set_rgb_one", shadow);
+	}
+
+	/* ensure shadow buffer and lamp textures will be updated */
+	add_user_list(&mat->lamps, lamp);
+	add_user_list(&lamp->materials, mat->ma);
+
+	return visifac;
+}
+
 /* export the GLSL shader */
 
 GPUShaderExport *GPU_shader_export(struct Scene *scene, struct Material *ma)

source/blender/gpu/shaders/gpu_shader_material.glsl

@@ -166,6 +166,15 @@ void camera(vec3 co, out vec3 outview, out float outdepth, out float outdist)
 	outview = normalize(co);
 }
 
+void lamp(vec4 col, vec3 lv, float dist, vec3 shadow, float visifac, out vec4 outcol, out vec3 outlv, out float outdist, out vec4 outshadow, out float outvisifac)
+{
+	outcol = col;
+	outlv = lv;
+	outdist = dist;
+	outshadow = vec4(shadow, 1.0);
+	outvisifac = visifac;
+}
+
 void math_add(float val1, float val2, out float outval)
 {
 	outval = val1 + val2;
@@ -1973,6 +1982,30 @@ void test_shadowbuf_vsm(vec3 rco, sampler2D shadowmap, mat4 shadowpersmat, float
 	}
 }
 
+void shadows_only(vec3 rco, sampler2DShadow shadowmap, mat4 shadowpersmat, float shadowbias, vec3 shadowcolor, float inp, out vec3 result)
+{
+	result = vec3(1.0);
+
+	if(inp > 0.0) {
+		float shadfac;
+
+		test_shadowbuf(rco, shadowmap, shadowpersmat, shadowbias, inp, shadfac);
+		result -= (1.0 - shadfac) * (vec3(1.0) - shadowcolor);
+	}
+}
+
+void shadows_only_vsm(vec3 rco, sampler2D shadowmap, mat4 shadowpersmat, float shadowbias, float bleedbias, vec3 shadowcolor, float inp, out vec3 result)
+{
+	result = vec3(1.0);
+
+	if(inp > 0.0) {
+		float shadfac;
+
+		test_shadowbuf_vsm(rco, shadowmap, shadowpersmat, shadowbias, bleedbias, inp, shadfac);
+		result -= (1.0 - shadfac) * (vec3(1.0) - shadowcolor);
+	}
+}
+
 void shade_light_texture(vec3 rco, sampler2D cookie, mat4 shadowpersmat, out vec4 result)
 {
 

source/blender/makesrna/RNA_access.h

@@ -493,6 +493,7 @@ extern StructRNA RNA_ShaderNodeExtendedMaterial;
 extern StructRNA RNA_ShaderNodeGeometry;
 extern StructRNA RNA_ShaderNodeHueSaturation;
 extern StructRNA RNA_ShaderNodeInvert;
+extern StructRNA RNA_ShaderNodeLampData;
 extern StructRNA RNA_ShaderNodeMapping;
 extern StructRNA RNA_ShaderNodeMaterial;
 extern StructRNA RNA_ShaderNodeMath;

source/blender/makesrna/intern/rna_internal.h

@@ -239,6 +239,7 @@ void rna_TextureSlot_brush_update(struct Main *bmain, struct Scene *scene, struc
 int rna_Armature_object_poll(struct PointerRNA *ptr, struct PointerRNA value);
 int rna_Camera_object_poll(struct PointerRNA *ptr, struct PointerRNA value);
 int rna_Curve_object_poll(struct PointerRNA *ptr, struct PointerRNA value);
+int rna_Lamp_object_poll(struct PointerRNA *ptr, struct PointerRNA value);
 int rna_Lattice_object_poll(struct PointerRNA *ptr, struct PointerRNA value);
 int rna_Mesh_object_poll(struct PointerRNA *ptr, struct PointerRNA value);
 

source/blender/makesrna/intern/rna_nodetree.c

@@ -3258,6 +3258,19 @@ static void def_sh_geometry(StructRNA *srna)
 	RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_Node_update");
 }
 
+static void def_sh_lamp(StructRNA *srna)
+{
+	PropertyRNA *prop;
+	
+	prop = RNA_def_property(srna, "lamp_object", PROP_POINTER, PROP_NONE);
+	RNA_def_property_pointer_sdna(prop, NULL, "id");
+	RNA_def_property_struct_type(prop, "Object");
+	RNA_def_property_flag(prop, PROP_EDITABLE);
+	RNA_def_property_pointer_funcs(prop, NULL, NULL, NULL, "rna_Lamp_object_poll");
+	RNA_def_property_ui_text(prop, "Lamp Object", "");
+	RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_Node_update");
+}
+
 static void def_sh_attribute(StructRNA *srna)
 {
 	PropertyRNA *prop;

source/blender/makesrna/intern/rna_object.c

@@ -1446,6 +1446,11 @@ int rna_Camera_object_poll(PointerRNA *UNUSED(ptr), PointerRNA value)
 	return ((Object *)value.id.data)->type == OB_CAMERA;
 }
 
+int rna_Lamp_object_poll(PointerRNA *UNUSED(ptr), PointerRNA value)
+{
+	return ((Object *)value.id.data)->type == OB_LAMP;
+}
+
 int rna_DupliObject_index_get(PointerRNA *ptr)
 {
 	DupliObject *dob = (DupliObject *)ptr->data;

source/blender/nodes/CMakeLists.txt

@@ -133,6 +133,7 @@ set(SRC
 	shader/nodes/node_shader_geom.c
 	shader/nodes/node_shader_hueSatVal.c
 	shader/nodes/node_shader_invert.c
+	shader/nodes/node_shader_lamp.c
 	shader/nodes/node_shader_mapping.c
 	shader/nodes/node_shader_material.c
 	shader/nodes/node_shader_math.c

source/blender/nodes/NOD_shader.h

@@ -47,6 +47,7 @@ void register_node_type_sh_group(void);
 void register_node_type_sh_output(void);
 void register_node_type_sh_material(void);
 void register_node_type_sh_camera(void);
+void register_node_type_sh_lamp(void);
 void register_node_type_sh_value(void);
 void register_node_type_sh_rgb(void);
 void register_node_type_sh_mix_rgb(void);

source/blender/nodes/NOD_static_types.h

@@ -56,6 +56,7 @@ DefNode( ShaderNode,     SH_NODE_MAPPING,         def_sh_mapping,         "MAPPI
 DefNode( ShaderNode,     SH_NODE_CURVE_VEC,       def_vector_curve,       "CURVE_VEC",      VectorCurve,      "Vector Curves",     ""              )
 DefNode( ShaderNode,     SH_NODE_CURVE_RGB,       def_rgb_curve,          "CURVE_RGB",      RGBCurve,         "RGB Curves",        ""              )
 DefNode( ShaderNode,     SH_NODE_CAMERA,          0,                      "CAMERA",         CameraData,       "Camera Data",       ""              )
+DefNode( ShaderNode,     SH_NODE_LAMP,            def_sh_lamp,            "LAMP",           LampData,         "Lamp Data",         ""              )
 DefNode( ShaderNode,     SH_NODE_MATH,            def_math,               "MATH",           Math,             "Math",              ""              )
 DefNode( ShaderNode,     SH_NODE_VECT_MATH,       def_vector_math,        "VECT_MATH",      VectorMath,       "Vector Math",       ""              )
 DefNode( ShaderNode,     SH_NODE_SQUEEZE,         0,                      "SQUEEZE",        Squeeze,          "Squeeze Value",     ""              )

source/blender/nodes/shader/nodes/node_shader_lamp.c

@@ -0,0 +1,86 @@
+/*
+ * ***** BEGIN GPL LICENSE BLOCK *****
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version. 
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * The Original Code is Copyright (C) 2013 Blender Foundation.
+ * All rights reserved.
+ *
+ * The Original Code is: all of this file.
+ *
+ * Contributor(s): none yet.
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+/** \file blender/nodes/shader/nodes/node_shader_lamp.c
+ *  \ingroup shdnodes
+ */
+
+
+#include "node_shader_util.h"
+
+/* **************** LAMP INFO  ******************** */
+static bNodeSocketTemplate sh_node_lamp_out[] = {
+	{	SOCK_RGBA, 0, N_("Color")},
+	{	SOCK_VECTOR, 0, N_("Light Vector")},
+	{	SOCK_FLOAT, 0, N_("Distance")},
+	{	SOCK_RGBA, 0, N_("Shadow")},
+	{	SOCK_FLOAT, 0, N_("Visibility Factor")},
+	{	-1, 0, ""	}
+};
+
+
+static void node_shader_exec_lamp(void *data, int UNUSED(thread), bNode *node, bNodeExecData *UNUSED(execdata), bNodeStack **UNUSED(in), bNodeStack **out)
+{
+	if (data) {
+		Object *ob = (Object *)node->id;
+
+		if (ob) {
+			ShadeInput *shi = ((ShaderCallData *)data)->shi;
+
+			shi->nodes = 1; /* temp hack to prevent trashadow recursion */
+			out[4]->vec[0] = RE_lamp_get_data(shi, ob, out[0]->vec, out[1]->vec, out[2]->vec, out[3]->vec);
+			shi->nodes = 0;
+		}
+	}
+}
+
+static int gpu_shader_lamp(GPUMaterial *mat, bNode *node, bNodeExecData *UNUSED(execdata), GPUNodeStack *in, GPUNodeStack *out)
+{
+	if (node->id) {
+		GPULamp *lamp = GPU_lamp_from_blender(GPU_material_scene(mat), (Object *)node->id, NULL);
+		GPUNodeLink *col, *lv, *dist, *visifac, *shadow;
+
+		visifac = GPU_lamp_get_data(mat, lamp, &col, &lv, &dist, &shadow);
+
+		return GPU_stack_link(mat, "lamp", in, out, col, lv, dist, shadow, visifac);
+	}
+
+	return 0;
+}
+
+void register_node_type_sh_lamp(void)
+{
+	static bNodeType ntype;
+
+	sh_node_type_base(&ntype, SH_NODE_LAMP, "Lamp Data", NODE_CLASS_INPUT, 0);
+	node_type_compatibility(&ntype, NODE_OLD_SHADING);
+	node_type_socket_templates(&ntype, NULL, sh_node_lamp_out);
+	node_type_exec(&ntype, NULL, NULL, node_shader_exec_lamp);
+	node_type_gpu(&ntype, gpu_shader_lamp);
+
+	nodeRegisterType(&ntype);
+}

source/blender/render/extern/include/RE_shader_ext.h

@@ -194,6 +194,7 @@ struct Tex;
 struct MTex;
 struct ImBuf;
 struct ImagePool;
+struct Object;
 
 /* this one uses nodes */
 int	multitex_ext(struct Tex *tex, float texvec[3], float dxt[3], float dyt[3], int osatex, struct TexResult *texres, struct ImagePool *pool, bool scene_color_manage);
@@ -203,11 +204,11 @@ int multitex_ext_safe(struct Tex *tex, float texvec[3], struct TexResult *texres
 int multitex_nodes(struct Tex *tex, float texvec[3], float dxt[3], float dyt[3], int osatex, struct TexResult *texres,
                    const short thread, short which_output, struct ShadeInput *shi, struct MTex *mtex,
                    struct ImagePool *pool);
+float RE_lamp_get_data(struct ShadeInput *shi, struct Object *lamp_obj, float col[4], float lv[3], float *dist, float shadow[4]);
 
 /* shaded view and bake */
 struct Render;
 struct Image;
-struct Object;
 
 int RE_bake_shade_all_selected(struct Render *re, int type, struct Object *actob, short *do_update, float *progress);
 struct Image *RE_bake_shade_get_image(void);

source/blender/render/intern/source/shadeoutput.c

@@ -1982,3 +1982,94 @@ void shade_lamp_loop(ShadeInput *shi, ShadeResult *shr)
 	shr->combined[3]= shr->alpha;
 }
 
+/* used for "Lamp Data" shader node */
+static float lamp_get_data_internal(ShadeInput *shi, GroupObject *go, float col[4], float lv[3], float *dist, float shadow[4])
+{
+	LampRen *lar = go->lampren;
+	float visifac, inp;
+
+	if (!lar || lar->type == LA_YF_PHOTON
+	    || ((lar->mode & LA_LAYER) && (lar->lay & shi->obi->lay) == 0)
+	    || (lar->lay & shi->lay) == 0)
+		return 0.0f;
+
+	if (lar->mode & LA_TEXTURE)
+		do_lamp_tex(lar, lv, shi, col, LA_TEXTURE);
+
+	visifac = lamp_get_visibility(lar, shi->co, lv, dist);
+
+	if (visifac == 0.0f
+	    || lar->type == LA_HEMI
+	    || (lar->type != LA_SPOT && !(lar->mode & LA_SHAD_RAY))
+	    || (R.r.scemode & R_BUTS_PREVIEW))
+		return visifac;
+
+	inp = dot_v3v3(shi->vn, lv);
+
+	if (inp > 0.0f) {
+		float shadfac[4];
+
+		shadow[0] = lar->shdwr;
+		shadow[1] = lar->shdwg;
+		shadow[2] = lar->shdwb;
+
+		if (lar->mode & LA_SHAD_TEX)
+			do_lamp_tex(lar, lv, shi, shadow, LA_SHAD_TEX);
+
+		lamp_get_shadow(lar, shi, inp, shadfac, shi->depth);
+
+		shadow[0] = 1.0f - ((1.0f - shadfac[0] * shadfac[3]) * (1.0f - shadow[0]));
+		shadow[1] = 1.0f - ((1.0f - shadfac[1] * shadfac[3]) * (1.0f - shadow[1]));
+		shadow[2] = 1.0f - ((1.0f - shadfac[2] * shadfac[3]) * (1.0f - shadow[2]));
+	}
+
+	return visifac;
+}
+
+float RE_lamp_get_data(ShadeInput *shi, Object *lamp_obj, float col[4], float lv[3], float *dist, float shadow[4])
+{
+	col[0] = col[1] = col[2] = 0.0f;
+	col[3] = 1.0f;
+	copy_v3_v3(lv, shi->vn);
+	*dist = 1.0f;
+	shadow[0] = shadow[1] = shadow[2] = shadow[3] = 1.0f;
+
+	if (lamp_obj->type == OB_LAMP) {
+		GroupObject *go;
+		Lamp *lamp = (Lamp *)lamp_obj->data;
+
+		col[0] = lamp->r * lamp->energy;
+		col[1] = lamp->g * lamp->energy;
+		col[2] = lamp->b * lamp->energy;
+
+		if (R.r.scemode & R_BUTS_PREVIEW) {
+			for (go = R.lights.first; go; go = go->next) {
+				/* "Lamp.002" is main key light of material preview */
+				if (strcmp(go->ob->id.name + 2, "Lamp.002") == 0)
+					return lamp_get_data_internal(shi, go, col, lv, dist, shadow);
+			}
+			return 0.0f;
+		}
+
+		if (shi->light_override) {
+			for (go = shi->light_override->gobject.first; go; go = go->next) {
+				if (go->ob == lamp_obj)
+					return lamp_get_data_internal(shi, go, col, lv, dist, shadow);
+			}
+		}
+
+		if (shi->mat && shi->mat->group) {
+			for (go = shi->mat->group->gobject.first; go; go = go->next) {
+				if (go->ob == lamp_obj)
+					return lamp_get_data_internal(shi, go, col, lv, dist, shadow);
+			}
+		}
+
+		for (go = R.lights.first; go; go = go->next) {
+			if (go->ob == lamp_obj)
+				return lamp_get_data_internal(shi, go, col, lv, dist, shadow);
+		}
+	}
+
+	return 0.0f;
+}

source/blenderplayer/bad_level_call_stubs/stubs.c

@@ -173,6 +173,7 @@ void modifier_skin_customdata_ensure(struct Object *ob) {STUB_ASSERT(0);}
 /* nodes */
 struct RenderResult *RE_GetResult(struct Render *re) {STUB_ASSERT(0); return (struct RenderResult *) NULL;}
 struct Render *RE_GetRender(const char *name) {STUB_ASSERT(0); return (struct Render *) NULL;}
+float RE_lamp_get_data(struct ShadeInput *shi, struct Object *lamp_obj, float col[3], float lv[3], float *dist) {STUB_ASSERT(0); return 0.0f;}
 
 /* blenkernel */
 void RE_FreeRenderResult(struct RenderResult *res) {STUB_ASSERT(0);}