Eevee: add blackbody shader node support.

This replaces the blackbody to RGB code with the simpler and faster one from
Cycles. It's a little different but the other placing using this is the legacy
volume drawing, so no need to stay compatible with that.

1 files changed, 14 insertions, 0 deletions

diff --git a/source/blender/gpu/shaders/gpu_shader_material.glsl b/source/blender/gpu/shaders/gpu_shader_material.glsl
index 71333149634..8d120ae8984 100644
--- a/source/blender/gpu/shaders/gpu_shader_material.glsl
+++ b/source/blender/gpu/shaders/gpu_shader_material.glsl
@@ -3075,6 +3075,20 @@ void node_volume_absorption(vec4 color, float density, out Closure result)
 #endif
 }
 
+void node_blackbody(float temperature, sampler2D spectrummap, out vec4 color)
+{
+    if(temperature >= 12000.0) {
+        color = vec4(0.826270103, 0.994478524, 1.56626022, 1.0);
+    }
+    else if(temperature < 965.0) {
+        color = vec4(4.70366907, 0.0, 0.0, 1.0);
+    }
+	else {
+		float t = (temperature - 965.0) / (12000.0 - 965.0);
+		color = vec4(texture(spectrummap, vec2(t, 0.0)).rgb, 1.0);
+	}
+}
+
 /* closures */
 
 void node_mix_shader(float fac, Closure shader1, Closure shader2, out Closure shader)