I've been trying to get to grips with multmatrix. For example, the following code - does the result actually exist e.g. is it a plane? Would it be useful for anything?  N = [ [ 1  , 1  ,0  , 0  ],       [  1 , 1  , 0, 0   ],       [ 0  , 0  , 1  , 0    ],       [ 0  , 0  , 0  , 1   ] ] ;  multmatrix(N)     sphere(10);

I think it squashes the sphere to zero thickness so it is no longer a manifold. Thrown together view shows purple shimmering. Union with a cube gives a warning Top level object is a 3D object: Simple: no Vertices: 38 Halfedges: 88 Edges: 44 Halffacets: 18 Facets: 9 Volumes: 2 UI-WARNING: Object may not be a valid 2-manifold and may need repair! location unknown <0,> On Thu, 8 Oct 2020 at 22:56, Ray West <raywest@raywest.com> wrote: > I've been trying to get to grips with multmatrix. For example, the > following code - does the result actually exist e.g. is it a plane? > Would it be useful for anything? > > > N = [ [ 1 , 1 ,0 , 0 ], > [ 1 , 1 , 0, 0 ], > [ 0 , 0 , 1 , 0 ], > [ 0 , 0 , 0 , 1 ] ] ; > multmatrix(N) sphere(10); > > > _______________________________________________ > OpenSCAD mailing list > Discuss@lists.openscad.org > http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org >