Convert BoolGrid -> MaskGrid

[kdmarrett]

Asking because all SDF interior methods convert directly to a boolean grid and none convert into a MaskGrid.

Alternatively, is there a way to go from an SDF -> MaskGrid directly. There are several functions that use "mask" but they all output bool grids.

Thank you

[kdmarrett]

I think this is a matter of copying the topology from a boolean grid into a mask grid, looking for an example in the test cases...

[kdmarrett]

In tools/Clip.h I found the function convertToMaskGrid