Cycles / Wavelength to RGB node:

* Added a node to convert wavelength (in nanometer, from 380nm to 780nm) to RGB values. This can be useful to match real world colors easier.

Example render:
http://www.pasteall.org/pic/show.php?id=53202

ToDo:
* Move some functions into an util file, maybe a common util_color.h or so.
* Test GPU, unfortunately sm_21 doesn't work for me yet. 

6 files changed, 59 insertions, 0 deletions

diff --git a/source/blender/blenkernel/BKE_node.h b/source/blender/blenkernel/BKE_node.h
index ef51abc419e..55f68fcb8bd 100644
--- a/source/blender/blenkernel/BKE_node.h
+++ b/source/blender/blenkernel/BKE_node.h
@@ -741,6 +741,7 @@ struct ShadeResult;
 #define SH_NODE_SUBSURFACE_SCATTERING	177
 #define SH_NODE_WIREFRAME				178
 #define SH_NODE_BSDF_TOON				179
+#define SH_NODE_WAVELENGTH				180
 
 /* custom defines options for Material node */
 #define SH_NODE_MAT_DIFF   1
diff --git a/source/blender/blenkernel/intern/node.c b/source/blender/blenkernel/intern/node.c
index e4eb7c49ace..f805005e911 100644
--- a/source/blender/blenkernel/intern/node.c
+++ b/source/blender/blenkernel/intern/node.c
@@ -3399,6 +3399,7 @@ static void registerShaderNodes(void)
 	register_node_type_sh_value();
 	register_node_type_sh_rgb();
 	register_node_type_sh_wireframe();
+	register_node_type_sh_wavelength();
 	register_node_type_sh_mix_rgb();
 	register_node_type_sh_valtorgb();
 	register_node_type_sh_rgbtobw();
diff --git a/source/blender/nodes/CMakeLists.txt b/source/blender/nodes/CMakeLists.txt
index 59f25326edb..cc1a5f8cee9 100644
--- a/source/blender/nodes/CMakeLists.txt
+++ b/source/blender/nodes/CMakeLists.txt
@@ -145,6 +145,7 @@ set(SRC
 	shader/nodes/node_shader_valToRgb.c
 	shader/nodes/node_shader_value.c
 	shader/nodes/node_shader_wireframe.c
+	shader/nodes/node_shader_wavelength.c
 	shader/nodes/node_shader_vectMath.c
 	shader/nodes/node_shader_add_shader.c
 	shader/nodes/node_shader_ambient_occlusion.c
diff --git a/source/blender/nodes/NOD_shader.h b/source/blender/nodes/NOD_shader.h
index 993a48495ad..edb0ba6f475 100644
--- a/source/blender/nodes/NOD_shader.h
+++ b/source/blender/nodes/NOD_shader.h
@@ -80,6 +80,7 @@ void register_node_type_sh_light_falloff(void);
 void register_node_type_sh_object_info(void);
 void register_node_type_sh_fresnel(void);
 void register_node_type_sh_wireframe(void);
+void register_node_type_sh_wavelength(void);
 void register_node_type_sh_layer_weight(void);
 void register_node_type_sh_tex_coord(void);
 void register_node_type_sh_particle_info(void);
diff --git a/source/blender/nodes/NOD_static_types.h b/source/blender/nodes/NOD_static_types.h
index bc6d5d598d2..8e3896f40f7 100644
--- a/source/blender/nodes/NOD_static_types.h
+++ b/source/blender/nodes/NOD_static_types.h
@@ -96,6 +96,7 @@ DefNode( ShaderNode,     SH_NODE_OBJECT_INFO,        0,                      "OB
 DefNode( ShaderNode,     SH_NODE_PARTICLE_INFO,      0,                      "PARTICLE_INFO",      ParticleInfo,     "Particle Info",     ""       )
 DefNode( ShaderNode,     SH_NODE_HAIR_INFO,          0,                      "HAIR_INFO",          HairInfo,         "Hair Info",         ""       )
 DefNode( ShaderNode,     SH_NODE_WIREFRAME,          def_sh_tex_wireframe,   "WIREFRAME",          Wireframe,        "Wireframe",         ""       )
+DefNode( ShaderNode,     SH_NODE_WAVELENGTH,         0,                      "WAVELENGTH",         Wavelength,       "Wavelength",        ""       )
 DefNode( ShaderNode,     SH_NODE_BUMP,               def_sh_bump,            "BUMP",               Bump,             "Bump",              ""       )
 DefNode( ShaderNode,     SH_NODE_NORMAL_MAP,         def_sh_normal_map,      "NORMAL_MAP",         NormalMap,        "Normal Map",        ""       )
 DefNode( ShaderNode,     SH_NODE_TANGENT,            def_sh_tangent,         "TANGENT",            Tangent,          "Tangent",           ""       )
diff --git a/source/blender/nodes/shader/nodes/node_shader_wavelength.c b/source/blender/nodes/shader/nodes/node_shader_wavelength.c
new file mode 100644
index 00000000000..182769e2b32
--- /dev/null
+++ b/source/blender/nodes/shader/nodes/node_shader_wavelength.c
@@ -0,0 +1,54 @@
+/*
+ * ***** 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) 2005 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"
+
+/* **************** Wavelength ******************** */
+static bNodeSocketTemplate sh_node_wavelength_in[] = {
+	{	SOCK_FLOAT, 1, N_("Wavelength"),	500.0f, 0.0f, 0.0f, 0.0f, 380.0f, 780.0f},
+	{	-1, 0, ""	}
+};
+
+static bNodeSocketTemplate sh_node_wavelength_out[] = {
+	{	SOCK_RGBA, 0, N_("Color")},
+	{	-1, 0, ""	}
+};
+
+/* node type definition */
+void register_node_type_sh_wavelength(void)
+{
+	static bNodeType ntype;
+
+	sh_node_type_base(&ntype, SH_NODE_WAVELENGTH, "Wavelength", NODE_CLASS_CONVERTOR, 0);
+	node_type_compatibility(&ntype, NODE_NEW_SHADING);
+	node_type_size_preset(&ntype, NODE_SIZE_MIDDLE);
+	node_type_socket_templates(&ntype, sh_node_wavelength_in, sh_node_wavelength_out);
+	node_type_init(&ntype, NULL);
+	node_type_storage(&ntype, "", NULL, NULL);
+
+	nodeRegisterType(&ntype);
+}