Inputs

Origin [XYZ ]

This global position defnes the starting point for the rays.

Direction [XYZ ]

This global direction vector defines the central ray that is sent into the 3D space from the Origin. However, depending on the Spread setting, the actual rays can deviate greatly from this direction.

Spread [0..100%]

This value defines the permittable deviation of the rays from the defined Direction setting. If set to 0%, the rays will follow the Direction setting precisely. In this case, the number of samples can also be reduced to a minimum since all rays will deliver the same result. Increasing Spread values will randomly spread the rays correspondingly and deliver a better feedback of the environment of the Origin in the selected direction of view. Increasing Spread values can, however, make it necessary to use more rays in order to produce a homogeneous result.

Min Ray Length [-∞..+∞m]

This ist the minimum distance a ray has to travel from the Origin in order to be included in the calculation.

Max Ray Length [-∞..+∞m]

This is the maximum length a ray may be. If a ray does not hit a surface within this distance from the Origin, it will no longer be included in the calculation.

Max Ray Depth [0..15]

This value defines the number of transparent surfaces that rays are premitted to pass through.

Ignore

This menu makes it possible to include or exclude objects to which this material is assigned from the calculation. The following options are available:

• None: Treats all surfaces equally and does not differentiate whether a surface with this or another material are hit.

• Same Object: Excludes surfaces to which the material is assigned. With regard to an Ambient Occlusion calculation, this would correspond to the Visible for AO option in a Compositing tag.

• Other Objects: Inverts the above function and only calculates surfaces to which this material is applies.

 Quality

Min Samples [0..999999]
Max Samples [0..999999]
Accuracy [0..100%]

As the node’s name already suggests, multiple rays are sent from the defined Origin. The number of rays sent out depends, among other things, on the Spread setting and also if the first rays sent even reach a surface within the defined Max Ray Length. The number of rays that is in fact sent out and the maximum number of rays is defined using the Quality menu. These settings reflect a Light object’s Area shadow settings (see Accuracy), for example, or the samples of an Ambient Occlusion shader (Standard renderer).