Cycles / Blackbody to RGB node:

* Added a node to convert a temperature in Kelvin to an RGB color. This can be used e.g. for lights, to easily find the right color temperature. 
= Some common temperatures =
Candle light: 1500 Kelvin
Sunset/Sunrise: 1850 Kelvin
Studio lamps: 3200 Kelvin
Horizon daylight: 5000 Kelvin

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

Thanks to Philipp Oeser (lichtwerk), who essentially contributed to this with a patch! :)

This is part of my GSoC 2013 project. SVN merge of r57424, r57487, r57507, r57525, r58253 and r58774

1 files changed, 26 insertions, 0 deletions

diff --git a/intern/cycles/render/shader.cpp b/intern/cycles/render/shader.cpp
index 21b43380f2c..5b326e0a017 100644
--- a/intern/cycles/render/shader.cpp
+++ b/intern/cycles/render/shader.cpp
@@ -18,6 +18,7 @@
 
 #include "background.h"
 #include "bssrdf.h"
+#include "blackbody.h"
 #include "device.h"
 #include "graph.h"
 #include "light.h"
@@ -51,6 +52,7 @@ Shader::Shader()
 	has_surface_transparent = false;
 	has_surface_emission = false;
 	has_surface_bssrdf = false;
+	has_converter_blackbody = false;
 	has_volume = false;
 	has_displacement = false;
 
@@ -127,6 +129,7 @@ ShaderManager::ShaderManager()
 {
 	need_update = true;
 	bssrdf_table_offset = TABLE_OFFSET_INVALID;
+	blackbody_table_offset = TABLE_OFFSET_INVALID;
 }
 
 ShaderManager::~ShaderManager()
@@ -218,6 +221,7 @@ void ShaderManager::device_update_common(Device *device, DeviceScene *dscene, Sc
 	uint *shader_flag = dscene->shader_flag.resize(shader_flag_size);
 	uint i = 0;
 	bool has_surface_bssrdf = false;
+	bool has_converter_blackbody = false;
 
 	foreach(Shader *shader, scene->shaders) {
 		uint flag = 0;
@@ -232,6 +236,8 @@ void ShaderManager::device_update_common(Device *device, DeviceScene *dscene, Sc
 			flag |= SD_HOMOGENEOUS_VOLUME;
 		if(shader->has_surface_bssrdf)
 			has_surface_bssrdf = true;
+		if(shader->has_converter_blackbody)
+			has_converter_blackbody = true;
 
 		shader_flag[i++] = flag;
 		shader_flag[i++] = shader->pass_id;
@@ -257,6 +263,21 @@ void ShaderManager::device_update_common(Device *device, DeviceScene *dscene, Sc
 		scene->lookup_tables->remove_table(bssrdf_table_offset);
 		bssrdf_table_offset = TABLE_OFFSET_INVALID;
 	}
+
+	/* blackbody lookup table */
+	KernelBlackbody *kblackbody = &dscene->data.blackbody;
+	
+	if(has_converter_blackbody && blackbody_table_offset == TABLE_OFFSET_INVALID) {
+		vector<float> table = blackbody_table();
+		blackbody_table_offset = scene->lookup_tables->add_table(dscene, table);
+		
+		kblackbody->table_offset = (int)blackbody_table_offset;
+	}
+	else if(!has_converter_blackbody && blackbody_table_offset != TABLE_OFFSET_INVALID) {
+		scene->lookup_tables->remove_table(blackbody_table_offset);
+		blackbody_table_offset = TABLE_OFFSET_INVALID;
+	}
+
 }
 
 void ShaderManager::device_free_common(Device *device, DeviceScene *dscene, Scene *scene)
@@ -266,6 +287,11 @@ void ShaderManager::device_free_common(Device *device, DeviceScene *dscene, Scen
 		bssrdf_table_offset = TABLE_OFFSET_INVALID;
 	}
 
+	if(blackbody_table_offset != TABLE_OFFSET_INVALID) {
+		scene->lookup_tables->remove_table(blackbody_table_offset);
+		blackbody_table_offset = TABLE_OFFSET_INVALID;
+	}
+
 	device->tex_free(dscene->shader_flag);
 	dscene->shader_flag.clear();
 }