Voxel Index Node

The Voxel Index node outputs the integer index of the voxel that the field is currently being evaluated on.

Unlike a position in object space, the voxel index refers to the discrete cell coordinates inside a voxel grid. This makes it possible to reason about neighboring voxels directly in index space, without converting through world or object space.

This node can be combined with nodes such as Integer Math and Sample Grid Index to sample values from nearby voxels by offsetting the indices.

Inputs

This node has no inputs.

Outputs

X, Y, Z

The integer indices of the current voxel in the grid along each axis.

These values identify which voxel is being sampled by the field at this evaluation point. They can be offset (for example, add or subtract 1 on X) and then passed to Sample Grid Index to read values from neighboring voxels.

Tile

Is Tile

Whether the current evaluation is happening on a tile rather than on a single voxel.

Some operations evaluate fields on tiles that cover multiple voxels at once for performance reasons. In those cases the coordinates given by X, Y, and Z alone are not enough to describe the full covered region.

If this is false, the extent is always 1.

Extent X, Extent Y, Extent Z

The number of voxels along each axis of the tile.

For a normal voxel, the extent on each axis is 1. For a tile that covers multiple voxels, the extents describe how many voxels are grouped together in X, Y, and Z.

These outputs can be used to detect and handle cases where an evaluation represents an aggregated region (a tile) instead of an individual voxel, so that the result is not misinterpreted as referring to just one voxel.