Page tree
Skip to end of metadata
Go to start of metadata

You are viewing an old version of this page. View the current version.

Compare with Current View Page History

« Previous Version 6 Next »

A point light.










The Radius of the point light is controlled using the Light Radius standard attribute.

Point Light Controls

Radius

The radius of the sphere that emits light in all directions.  Increasing the Radius will soften the lit region edge and the shadows casted by the spot light.

Visible to Camera

Makes the light source visible to the camera (a.k.a primary rays). Since the point light is rendered as a sphere with the specified Radius, the visible shape will be a sphere. Note that a Radius of 0 might still produce a very tiny visible dot. This option is only available in 3Delight for Katana.


Light Intensity and Color Controls

Color

Defines the light color.

Intensity

Species the light intensity.

Exposure

This is an additional control over the standard light intensity. Exposure is in many cases a preferred control due to its likeness to photography. Final light intensity is thus computed by:

I = intensity * pow(2, exposure)

Decay Rate

Specify the rate at which the light intensity decreases in function of the distance to the light source. The available values are:

No Decay
Light intensity remains constant with respect to distance.
Linear
Light intensity decreases linearly with distance.
Quadratic
Light intensity decreases proportionally to the square of the distance. This is the physically correct behaviour.
Cubic
Light intensity decreases proportionally to the cube of the distance.

Fine Tuning the Light Contribution to the Shading Components

It is sometimes useful to have a fine and direct control on how the light intensity affects various shading components. The following controls allows for that:

Diffuse Contribution

Specifies a multiplier for the light contribution to diffuse shading.

Specular Contribution

Specifies a multiplier for the light contribution to specular shading.

Hair Contribution

Specifies a multiplier for the light contribution to hair shading.

Volume Contribution

Specifies a multiplier for the light contribution to volumetric effects in atmosphere and OpenVDB volumes.



  • No labels