34 lines
1.3 KiB
Markdown
34 lines
1.3 KiB
Markdown
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# Blackbody Node
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## Description
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Samples a **Gradient** that simulates the effect of black body radiation.
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The calculations in this node are based on data gathered by Mitchell Charity.
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This node outputs color in linear RGB space and preforms the conversion using a D65 whitepoint and a CIE 1964 10 degree color space.
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For more information, see [What color is a blackbody?](http://www.vendian.org/mncharity/dir3/blackbody/)
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## Ports
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| Name | Direction | Type | Binding | Description |
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|:------------ |:-------------|:-----|:---|:---|
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| Temperature | Input | Float | None | Temperature or temperature map in Kelvin to sample. |
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| Out | Output | Vector 3 | None | Intensity represented by color in Vector 3. |
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## Generated Code Example
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The following example code represents one possible outcome of this node.
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```
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void Unity_Blackbody_float(float Temperature, out float3 Out)
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{
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float3 color = float3(255.0, 255.0, 255.0);
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color.x = 56100000. * pow(Temperature,(-3.0 / 2.0)) + 148.0;
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color.y = 100.04 * log(Temperature) - 623.6;
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if (Temperature > 6500.0) color.y = 35200000.0 * pow(Temperature,(-3.0 / 2.0)) + 184.0;
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color.z = 194.18 * log(Temperature) - 1448.6;
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color = clamp(color, 0.0, 255.0)/255.0;
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if (Temperature < 1000.0) color *= Temperature/1000.0;
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Out = color;
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}
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```
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