Cycles: Add Support for IES files as textures for light strength

This patch adds support for IES files, a file format that is commonly used to store the directional intensity distribution of light sources.
The new IES node is supposed to be plugged into the Strength input of the Emission node of the lamp.

Since people generating IES files do not really seem to care about the standard, the parser is flexible enough to accept all test files I have tried.
Some common weirdnesses are distributing values over multiple lines that should go into one line, using commas instead of spaces as delimiters and adding various useless stuff at the end of the file.

The user interface of the node is similar to the script node, the user can either select an internal Text or load a file.
Internally, IES files are handled similar to Image textures: They are stored in slots by the LightManager and each unique IES is assigned to one slot.

The local coordinate system of the lamp is used, so that the direction of the light can be changed. For UI reasons, it's usually best to add an area light,
rotate it and then change its type, since especially the point light does not immediately show its local coordinate system in the viewport.

Reviewers: #cycles, dingto, sergey, brecht

Reviewed By: #cycles, dingto, brecht

Subscribers: OgDEV, crazyrobinhood, secundar, cardboard, pisuke, intrah, swerner, micah_denn, harvester, gottfried, disnel, campbellbarton, duarteframos, Lapineige, brecht, juicyfruit, dingto, marek, rickyblender, bliblubli, lockal, sergey

Differential Revision: https://developer.blender.org/D1543

11 files changed, 158 insertions, 0 deletions

diff --git a/source/blender/blenkernel/BKE_node.h b/source/blender/blenkernel/BKE_node.h
index efad8e48e3d..bd3b191c96c 100644
--- a/source/blender/blenkernel/BKE_node.h
+++ b/source/blender/blenkernel/BKE_node.h
@@ -789,6 +789,7 @@ struct ShadeResult;
 #define SH_NODE_UVALONGSTROKE			191
 #define SH_NODE_TEX_POINTDENSITY		192
 #define SH_NODE_BSDF_PRINCIPLED         193
+#define SH_NODE_TEX_IES                 195
 #define SH_NODE_BEVEL                   197
 #define SH_NODE_DISPLACEMENT            198
 #define SH_NODE_VECTOR_DISPLACEMENT     199
diff --git a/source/blender/blenkernel/intern/bpath.c b/source/blender/blenkernel/intern/bpath.c
index e9a8de4469d..cc4c28e8016 100644
--- a/source/blender/blenkernel/intern/bpath.c
+++ b/source/blender/blenkernel/intern/bpath.c
@@ -560,6 +560,10 @@ void BKE_bpath_traverse_id(Main *bmain, ID *id, BPathVisitor visit_cb, const int
 						NodeShaderScript *nss = (NodeShaderScript *)node->storage;
 						rewrite_path_fixed(nss->filepath, visit_cb, absbase, bpath_user_data);
 					}
+					else if (node->type == SH_NODE_TEX_IES) {
+						NodeShaderTexIES *ies = (NodeShaderTexIES *)node->storage;
+						rewrite_path_fixed(ies->filepath, visit_cb, absbase, bpath_user_data);
+					}
 				}
 			}
 			break;
@@ -576,6 +580,10 @@ void BKE_bpath_traverse_id(Main *bmain, ID *id, BPathVisitor visit_cb, const int
 						NodeShaderScript *nss = (NodeShaderScript *)node->storage;
 						rewrite_path_fixed(nss->filepath, visit_cb, absbase, bpath_user_data);
 					}
+					else if (node->type == SH_NODE_TEX_IES) {
+						NodeShaderTexIES *ies = (NodeShaderTexIES *)node->storage;
+						rewrite_path_fixed(ies->filepath, visit_cb, absbase, bpath_user_data);
+					}
 				}
 			}
 			break;
diff --git a/source/blender/blenkernel/intern/node.c b/source/blender/blenkernel/intern/node.c
index 5d4b1ae8170..521874bb14f 100644
--- a/source/blender/blenkernel/intern/node.c
+++ b/source/blender/blenkernel/intern/node.c
@@ -3640,6 +3640,7 @@ static void registerShaderNodes(void)
 	register_node_type_sh_tex_checker();
 	register_node_type_sh_tex_brick();
 	register_node_type_sh_tex_pointdensity();
+	register_node_type_sh_tex_ies();
 }
 
 static void registerTextureNodes(void)
diff --git a/source/blender/editors/space_node/drawnode.c b/source/blender/editors/space_node/drawnode.c
index 5665a5cff2d..ea8d4b36d3b 100644
--- a/source/blender/editors/space_node/drawnode.c
+++ b/source/blender/editors/space_node/drawnode.c
@@ -1109,6 +1109,21 @@ static void node_shader_buts_hair(uiLayout *layout, bContext *UNUSED(C), Pointer
 	uiItemR(layout, ptr, "component", 0, "", ICON_NONE);
 }
 
+static void node_shader_buts_ies(uiLayout *layout, bContext *UNUSED(C), PointerRNA *ptr)
+{
+	uiLayout *row;
+
+	row = uiLayoutRow(layout, false);
+	uiItemR(row, ptr, "mode", UI_ITEM_R_EXPAND, NULL, ICON_NONE);
+
+	row = uiLayoutRow(layout, true);
+
+	if (RNA_enum_get(ptr, "mode") == NODE_IES_INTERNAL)
+		uiItemR(row, ptr, "ies", 0, "", ICON_NONE);
+	else
+		uiItemR(row, ptr, "filepath", 0, "", ICON_NONE);
+}
+
 static void node_shader_buts_script(uiLayout *layout, bContext *UNUSED(C), PointerRNA *ptr)
 {
 	uiLayout *row;
@@ -1290,6 +1305,9 @@ static void node_shader_set_butfunc(bNodeType *ntype)
 		case SH_NODE_OUTPUT_LINESTYLE:
 			ntype->draw_buttons = node_buts_output_linestyle;
 			break;
+		case SH_NODE_TEX_IES:
+			ntype->draw_buttons = node_shader_buts_ies;
+			break;
 		case SH_NODE_BEVEL:
 			ntype->draw_buttons = node_shader_buts_bevel;
 			break;
diff --git a/source/blender/makesdna/DNA_node_types.h b/source/blender/makesdna/DNA_node_types.h
index 8d3ab29a2fb..95101ac1e51 100644
--- a/source/blender/makesdna/DNA_node_types.h
+++ b/source/blender/makesdna/DNA_node_types.h
@@ -893,6 +893,12 @@ typedef struct NodeShaderUVMap {
 	char uv_map[64];
 } NodeShaderUVMap;
 
+typedef struct NodeShaderTexIES {
+	int mode;
+
+	char filepath[1024]; /* 1024 = FILE_MAX */
+} NodeShaderTexIES;
+
 typedef struct NodeSunBeams {
 	float source[2];
 
@@ -906,6 +912,9 @@ typedef struct NodeSunBeams {
 /* script node flag */
 #define NODE_SCRIPT_AUTO_UPDATE		1
 
+/* ies node mode */
+#define NODE_IES_INTERNAL		0
+#define NODE_IES_EXTERNAL		1
 
 /* frame node flags */
 #define NODE_FRAME_SHRINK		1	/* keep the bounding box minimal */
diff --git a/source/blender/makesrna/RNA_access.h b/source/blender/makesrna/RNA_access.h
index e512aebfa71..73beee51a8b 100644
--- a/source/blender/makesrna/RNA_access.h
+++ b/source/blender/makesrna/RNA_access.h
@@ -529,6 +529,7 @@ extern StructRNA RNA_ShaderNodeCombineRGB;
 extern StructRNA RNA_ShaderNodeExtendedMaterial;
 extern StructRNA RNA_ShaderNodeGeometry;
 extern StructRNA RNA_ShaderNodeHueSaturation;
+extern StructRNA RNA_ShaderNodeIESLight;
 extern StructRNA RNA_ShaderNodeInvert;
 extern StructRNA RNA_ShaderNodeLampData;
 extern StructRNA RNA_ShaderNodeMapping;
diff --git a/source/blender/makesrna/intern/rna_nodetree.c b/source/blender/makesrna/intern/rna_nodetree.c
index f5c464c0758..8dbb133a8ac 100644
--- a/source/blender/makesrna/intern/rna_nodetree.c
+++ b/source/blender/makesrna/intern/rna_nodetree.c
@@ -2946,6 +2946,30 @@ static bNodeSocket *rna_NodeOutputFile_slots_new(ID *id, bNode *node, bContext *
 	return sock;
 }
 
+static void rna_ShaderNodeTexIES_mode_set(PointerRNA *ptr, int value)
+{
+	bNode *node = (bNode *)ptr->data;
+	NodeShaderTexIES *nss = node->storage;
+
+	if (nss->mode != value) {
+		nss->mode = value;
+		nss->filepath[0] = '\0';
+
+		/* replace text datablock by filepath */
+		if (node->id) {
+			Text *text = (Text *)node->id;
+
+			if (value == NODE_IES_EXTERNAL && text->name) {
+				BLI_strncpy(nss->filepath, text->name, sizeof(nss->filepath));
+				BLI_path_rel(nss->filepath, G.main->name);
+			}
+
+			id_us_min(node->id);
+			node->id = NULL;
+		}
+	}
+}
+
 static void rna_ShaderNodeScript_mode_set(PointerRNA *ptr, int value)
 {
 	bNode *node = (bNode *)ptr->data;
@@ -3293,6 +3317,12 @@ static const EnumPropertyItem node_script_mode_items[] = {
 	{0, NULL, 0, NULL, NULL}
 };
 
+static EnumPropertyItem node_ies_mode_items[] = {
+	{NODE_IES_INTERNAL, "INTERNAL", 0, "Internal", "Use internal text datablock"},
+	{NODE_IES_EXTERNAL, "EXTERNAL", 0, "External", "Use external .ies file"},
+	{0, NULL, 0, NULL, NULL}
+};
+
 static const EnumPropertyItem node_principled_distribution_items[] = {
 	{SHD_GLOSSY_GGX, "GGX", 0, "GGX", ""},
 	{SHD_GLOSSY_MULTI_GGX, "MULTI_GGX", 0, "Multiscatter GGX", ""},
@@ -4471,6 +4501,32 @@ static void def_sh_subsurface(StructRNA *srna)
 	RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_ShaderNodeSubsurface_update");
 }
 
+static void def_sh_tex_ies(StructRNA *srna)
+{
+	PropertyRNA *prop;
+
+	prop = RNA_def_property(srna, "ies", PROP_POINTER, PROP_NONE);
+	RNA_def_property_pointer_sdna(prop, NULL, "id");
+	RNA_def_property_struct_type(prop, "Text");
+	RNA_def_property_flag(prop, PROP_EDITABLE | PROP_ID_REFCOUNT);
+	RNA_def_property_ui_text(prop, "IES Text", "Internal IES file");
+	RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_Node_update");
+
+	RNA_def_struct_sdna_from(srna, "NodeShaderTexIES", "storage");
+
+	prop = RNA_def_property(srna, "filepath", PROP_STRING, PROP_FILEPATH);
+	RNA_def_property_ui_text(prop, "File Path", "IES light path");
+	RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_Node_update");
+
+	prop = RNA_def_property(srna, "mode", PROP_ENUM, PROP_NONE);
+	RNA_def_property_enum_funcs(prop, NULL, "rna_ShaderNodeTexIES_mode_set", NULL);
+	RNA_def_property_enum_items(prop, node_ies_mode_items);
+	RNA_def_property_ui_text(prop, "Source", "Whether the IES file is loaded from disk or from a Text datablock");
+	RNA_def_property_update(prop, NC_NODE | NA_EDITED, "rna_Node_update");
+
+	RNA_def_struct_sdna_from(srna, "bNode", NULL);
+}
+
 static void def_sh_script(StructRNA *srna)
 {
 	PropertyRNA *prop;
diff --git a/source/blender/nodes/CMakeLists.txt b/source/blender/nodes/CMakeLists.txt
index 5247599bdf7..cc0bef30047 100644
--- a/source/blender/nodes/CMakeLists.txt
+++ b/source/blender/nodes/CMakeLists.txt
@@ -177,6 +177,7 @@ set(SRC
 	shader/nodes/node_shader_fresnel.c
 	shader/nodes/node_shader_geometry.c
 	shader/nodes/node_shader_holdout.c
+	shader/nodes/node_shader_ies_light.c
 	shader/nodes/node_shader_layer_weight.c
 	shader/nodes/node_shader_light_falloff.c
 	shader/nodes/node_shader_light_path.c
diff --git a/source/blender/nodes/NOD_shader.h b/source/blender/nodes/NOD_shader.h
index b00307ed7fb..7cb52cda550 100644
--- a/source/blender/nodes/NOD_shader.h
+++ b/source/blender/nodes/NOD_shader.h
@@ -138,6 +138,7 @@ void register_node_type_sh_tex_musgrave(void);
 void register_node_type_sh_tex_noise(void);
 void register_node_type_sh_tex_checker(void);
 void register_node_type_sh_bump(void);
+void register_node_type_sh_tex_ies(void);
 
 #endif
 
diff --git a/source/blender/nodes/NOD_static_types.h b/source/blender/nodes/NOD_static_types.h
index bc90e33ed03..5864b3deb39 100644
--- a/source/blender/nodes/NOD_static_types.h
+++ b/source/blender/nodes/NOD_static_types.h
@@ -130,6 +130,7 @@ DefNode( ShaderNode,     SH_NODE_COMBXYZ,            0,                      "CO
 DefNode( ShaderNode,     SH_NODE_BEVEL,              def_sh_bevel,           "BEVEL",              Bevel,            "Bevel",             ""       )
 DefNode( ShaderNode,     SH_NODE_DISPLACEMENT,       def_sh_displacement,    "DISPLACEMENT",       Displacement,     "Displacement",      ""       )
 DefNode( ShaderNode,     SH_NODE_VECTOR_DISPLACEMENT,def_sh_vector_displacement,"VECTOR_DISPLACEMENT",VectorDisplacement,"Vector Displacement",""  )
+DefNode( ShaderNode,     SH_NODE_TEX_IES,            def_sh_tex_ies,         "TEX_IES",            TexIES,           "IES Texture",       ""       )
 
 DefNode( CompositorNode, CMP_NODE_VIEWER,         def_cmp_viewer,         "VIEWER",         Viewer,           "Viewer",            ""              )
 DefNode( CompositorNode, CMP_NODE_RGB,            0,                      "RGB",            RGB,              "RGB",               ""              )
diff --git a/source/blender/nodes/shader/nodes/node_shader_ies_light.c b/source/blender/nodes/shader/nodes/node_shader_ies_light.c
new file mode 100644
index 00000000000..8084f445e34
--- /dev/null
+++ b/source/blender/nodes/shader/nodes/node_shader_ies_light.c
@@ -0,0 +1,61 @@
+/*
+ * ***** 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) 2018 Blender Foundation.
+ * All rights reserved.
+ *
+ * The Original Code is: all of this file.
+ *
+ * Contributor(s): none yet.
+ *
+ * ***** END GPL LICENSE BLOCK *****
+ */
+
+#include "../node_shader_util.h"
+
+/* **************** IES Light ******************** */
+
+static bNodeSocketTemplate sh_node_tex_ies_in[] = {
+	{	SOCK_VECTOR, 1, N_("Vector"),		0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 1.0f, PROP_NONE, SOCK_HIDE_VALUE},
+	{	SOCK_FLOAT, 1, N_("Strength"),		1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 1000000.0f, PROP_NONE},
+	{	-1, 0, ""	}
+};
+
+static bNodeSocketTemplate sh_node_tex_ies_out[] = {
+	{	SOCK_FLOAT, 0, N_("Fac")},
+	{	-1, 0, ""	}
+};
+
+static void node_shader_init_tex_ies(bNodeTree *UNUSED(ntree), bNode *node)
+{
+	NodeShaderTexIES *tex = MEM_callocN(sizeof(NodeShaderTexIES), "NodeShaderIESLight");
+	node->storage = tex;
+}
+
+/* node type definition */
+void register_node_type_sh_tex_ies(void)
+{
+	static bNodeType ntype;
+
+	sh_node_type_base(&ntype, SH_NODE_TEX_IES, "IES Texture", NODE_CLASS_TEXTURE, 0);
+	node_type_compatibility(&ntype, NODE_NEW_SHADING);
+	node_type_socket_templates(&ntype, sh_node_tex_ies_in, sh_node_tex_ies_out);
+	node_type_init(&ntype, node_shader_init_tex_ies);
+	node_type_storage(&ntype, "NodeShaderTexIES", node_free_standard_storage, node_copy_standard_storage);
+
+	nodeRegisterType(&ntype);
+}