Octane Blackbody Emission
The Black Body emission node uses Temperature (expressed via the Kelvin scale) and Power to control the color and intensity of the light, respectively.
All objects radiate energy warmer than 0 Kelvin, but this energy is not visible to human vision. The average body temperature for a human, expressed in Kelvin, is 310.15 K — too low for our eyes to register as a source of illumination (as this value is actually in the infrared spectrum), though we do perceive the warmth we generate.
The lowest end of the visible spectrum is right around 800 K (embers). A match flame is 1800 K and a standard "Edison" incandescent light bulb is 2800 K. The spectrum below shows color temperature in Kelvin for varying light sources.
In other words, when temperature increases beyond a certain point, visible light is emitted, starting with warmer reddish values all the way through cooler blue values.
Node Input/Outputs
- Node inputs include:
Efficiency - this input allows you to use a texture or color as an input to the Emission surface.
Power - Controls the brightness of the Emission surface. This setting is measured in Wattage and thus uses real world units.
Temperature - The temperature of the Emission in Kelvin.
Distribution - The distribution controls the pattern of the light. This can be set to a floattexture and an image or IES file can be loaded.
Sampling Rate - Emission nodes have a Sampling Rate parameter to control how much weight is given to the emitter when picking an emitter to sample. This allows you to choose which light sources will receive more samples. The emission sampling rate can be set to 0, which means that the emitter will be excluded from the direct light calculation.
Node Options/Attributes
Octane Blackbody Node Example Usage
An example of the nodes usage is shown below. IN this example, the Blackbody Emission has been set to 350.0 Kelvin. This will give a Red-ish light emitted from the Object Surface.
OctaneRender IPR Output
