Function join_is_not_empty 

pub fn join_is_not_empty(
    first: VoxelShape,
    second: VoxelShape,
    op: BooleanOp,
) -> bool

Returns true if applying op to two voxel shapes produces any filled space.

This is the box-backed equivalent of vanilla Shapes.joinIsNotEmpty. It decomposes both shapes into a shared coordinate grid and tests occupancy in each cell. The current representation does not materialize a joined shape; it answers the boolean query needed for full-block and occlusion checks.

Panics

Panics if op.apply(false, false) is true, matching vanilla’s invalid operation guard for unbounded outside-space results.