POPX

Light

v1.3.0
Tools

Summary

Light is a light source tool for the POPX Path Tracer's lighting system. It functions similarly to TouchDesigner's built-in Light COMP but provides light parameters specifically designed for the Path Tracer's physically-based rendering pipeline.

The Light tool supports five light types: Point Light for omnidirectional illumination, Spot Light with cone angle and falloff controls, Area Light for soft rectangular illumination, Volumetric Light for atmospheric light effects with ray marching, and Environment Light for image-based lighting using an HDR environment map. Each light can be configured with color, intensity, distance attenuation, and optional texture/environment map projection.

Lights are referenced by the Path Tracer through the Render TOP's Lights parameter. To visualize the light as geometry in the scene or render the Environment Light as a background, toggle on the Render Flag on the Light COMP.

Parameters

Light TypeType
Selects the type of light source.
Point LightpointSpot LightspotArea LightareaVolumetric LightvolumetricEnvironment Lightenv
Light ColorColor
RGB color of the light.
Light ColorColorrLight ColorColorgLight ColorColorb
DimmerDimmer
Light intensity multiplier.
Bi-DirectionalBidirectional
Area and spot lights emit from both sides of surface.
Cone AngleConeangle
Spotlight cone angle in degrees.
Cone DeltaConedelta
Spotlight falloff width at cone edge.
Cone RolloffConeroll
Spotlight intensity falloff curve.
Volumetric StepsVolsteps
Number of ray marching steps for volumetric light evaluation.
Volumetric Density ScaleVoldensityscale
Multiplier for volumetric light density.
Distance-AttenuatedAttenuated
Enables distance-based light intensity falloff.
Attenuation StartAttenuationstart
Distance at which light attenuation begins.
Attenuation EndAttenuationend
Distance at which light attenuation reaches zero.
Attenuation RolloffAttenuationexp
Exponent controlling the attenuation falloff curve.
Diffuse ContributionDiffusecontrib
Controls how much this light contributes to diffuse shading.
Specular ContributionSpecularcontrib
Controls how much this light contributes to specular reflections.
Texture/Environment MapTexturemap
Texture map projected from the light source, or HDR environment map for Environment Light.
Environment Map RotateEnvlightmaprotate
Rotation of the environment map in degrees. Enabled when Light Type is Environment Light.
Environment Map RotateEnvlightmaprotatexEnvironment Map RotateEnvlightmaprotateyEnvironment Map RotateEnvlightmaprotatez
Free Extra GPU MemoryFreeextragpumem
Free memory that has accumulated when output memory has grown and shrunk.