RedSDK Physical Light Luminance
About Physical LightFrom help files - A physical light uses the definition of light sources from physical parameters issued from lamp manufacturers. A physical light is associated to a mesh ( The 3D Object associated with the Luminance) that defines the light surface that will emit light in the scene. Therefore a physical light can be of any shape.Physical lights are rendered on the CPU using sampling and are approximated on the GPU. There are two possible approximations for a physical light on the GPU:
- If the physical light is linked to a rectangular mesh, then the physical light is automatically turned into an Area light.
- If the physical light is linked to a mesh with any other geometric shape, then the physical light is automatically turned into a Point light.
- Power â€“ Sets the power of the light in Watts.
- Luminous Efficiency â€“ luminous efficiency of the light in percentage (%).
- Intensity decay â€“ Set the rate at which the lights power diminishes.
- Color â€“ Sets the color of the light.
- Color Temperature â€“ Alternate color value which supports definition of the color by temperature in Kelvin.
- Color Affect â€“ Sets the relative intensity (power) of the color light.
- Samples Count â€“ Sets the maximum number of light samples.
- Double Sided -
- Shadows â€“ Sets whether the light will generate shadows, or not.
- Shadow Color â€“ Specifies the color of shadows created by the light.
- Shadow Map - turns on automatic shadow map generation, shadow maps take a snapshot from the light source and compares this to the render from the camera perspective, this can may rendering quicker, but can also reduce the quality, also shadow maps may not produce accurate renders of transparent objects,
- Texture File Name â€“ Rather than using a single constant color for the whole light, you can setup a texture from which light color will be read. Using a texture, you can simulate projectors or complex light filters.
Images used as the texture can be simple or complex, below shows two images and their outcome when used as a texture file.
- IES File Name â€“ Manufacturers measure the behavior of their bulbs and store their directional contribution into IES files. Those files are available for most of the bulb models directly from the manufacturers' web sites. Even if IES files store information about the shape of the emitter, they are not used here.
- Caustics â€“ Specifies whether the light will generate caustic effects.
The difficulty with this 'standard' physical light is that the light direction is difficult to control.
- Visible Geometry - Specifies whether the physical geometry of the associate 3D objects will be seen.
- Covert emitter units to metric
- Extra Scale
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RedSDK Luminance Reference