Volume Scalar Attribute

The Volume Scalar Attribute is a shading node that allows for programmable volume shading when used with a Standard Volume shader. For example, a VDB grid can be loaded and it can be displaced with a noise shader. This can be used for many creative effects and adding detail to low resolution volumes.

This node has no effect when not used with a Standard Volume shader.

Example Graph

In the example below, a Volume Scalar Attribute node is used to load a density channel and directly drive the density input on a Standard Volume shader. This density channel is displaced by three Maxon noises, each uses the same noise type but with a different seed — this ensures that the volume is adequately displaced in 3D space. The three noises are fed into a vector maker which is then fed into a Vector Change Range. The Vector Change Range has the Output Min and Max on all three axes set to -1 to +1, this centers the displacement on the volumes axis. After this, a vector multiply node is used to control the intensity of displacement on each axis.