From MagicaVoxel Community Wiki
- either the whole model if nothing is selected
- or the selected voxels
If no axis is specified, transformation applies to all of them. Factor must be a rational number; negative values behaves like a mirror.If the factor enlarges the model bigger than the current object size, the limits are modified accordingly, within a 126 voxels cap for each axis.
The center of the model after transformation is located at the geometric center of the voxels concerned by the transformation.
- Centroid on Wikipedia