Cast Shadow Node

• Directional: A light that is parallel in the scene. Each “beam” of light follows the direction defined by the light source and target, and point in the same direction. This type of light is used when the light source is far away or very big, like the sun.
• Point: A light that illuminates everything around it. Its “beam” of light will go in all directions like a fire.

• Smooth: The shadow effect will have smooth edges.
• Sharp: The shadow effect will have sharp edges.

The shadow length defines how far, in pixels, the shadow will be cast after first being occluded on the surface.

A value of 0 will not limit the shadow length, and instead, it will be defined by the position of the light source.

A lower value will create a smaller shadow and a higher value will create a longer shadow that falls off as it recedes from the occluded point.

When calculating the cast shadows, this value is used as a bias comparing the light’s angle and the occlusion angle. A positive value will increase the occlusion angle and the shaded areas will appear darker. A negative value will decrease the occlusion angle and the shaded areas will lighten.

This bias is applied prior to all further calculations.

In order to separate different surface elevations, the final blur threshold defines a bucket-range in which the shadows are separated and blurred together.

This can be used to keep certain edges of the cast shadow sharp, and other areas blended.

This value works in conjunction with the Anti-Alias Blend.

When a shadow begins on an occluded surface, the bias is the amount of pixels ignored before rendering the shadow . This allows you to recede a shadow from its initial occlusion source.

This value works in conjunction with the Anti-Alias Bias.

When a shadow begins on a surface, the shadow is blended with the surface for the amount of pixels defined by the Anti-Alias Blend.

Defines the rate of change in a shadow.

A lower value will produce a shadow that appears softer and changes from light to dark slowly. A higher value will appear sharper and darker, and changes from light to dark quickly.

The Shadow Bias can be used to lighten a shadow. This value is subtracted from the shadow’s value when calculated.

The Abruptness is a value that is used to change the sharpness of a shadow and affects its rate of change.

A value of one produces a linear shadow that falls off smoothly, a higher value will cause darker areas to become darker, and lighter areas to become lighter.

The colour used for the Cast Shadow.

When the Cast Shadow uses the Image Colour, this colour is used as a tint and is applied to the image colour based on the Image Colour Intensity.

When Use Image Colour is checked, the incoming colour and value of the source image is used to tint the Cast Shadow colour.

This percentage value defines how much of the Cast Shadow colour is provided by the source image.

For more advanced cast shadows, the sampling values define the number of times the cast shadow is calculated in order to produce a higher quality render.

The Sample Count defines the number of points on the light source that are sampled in a radius parallel with the surface.

A higher number will produce a more rounded shadow with more refined edges.

When using a higher Sampling Count, the sample size defines the range used when sampling points from the light source. The samples are taken in an even distribution around the point of the light source at a radius defined by the sample size.

The Soft Shadow Sample Count defines the number of points on the light source that are sampled in a line perpendicular with the surface.

This has less effect than the Sample Count, but is useful when calculating softer shadows with a larger Soft Shadow Sample Size.

This value defines how many times the shadow is resampled when occluded.

The Soft Shadow Sample Size is a useful attribute that helps to define the falloff of a shadow as it recedes from the light source. A higher value will cause the trailing edge of a shadow to appear softer.