Clipping to the Container Cell

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Universes are truncated by the boundaries of the cell they fill. Moritz’s default action is the add the cell description of the container cell to the description of the cells of the universe that fills the cell when computing the 3D polygons for those cells. This clipping the container cell is not always necessary for the 3D display, especially for universes that do not fill lattices. In some cases, often when quadric surfaces are present, the additional cell description items from the container cell can introduce artifacts; the problem is exacerbated when the filling universes are transformed.

This figure  shows two transformed instances of a universe filling two cells outside a spherical chamber. The container cells are the blue and green cylinders shown in wireframe. Except for the (invisible) air surrounding the objects, the universes fit within the container cells—there is no need to clip the cells to the container cell.

The clipping can be turned off for all non-lattice filling universes by unchecking Clip Universes to Container on the 3D Options property page. The option can be set for individual universes on the Universe dialog. Clipping can also be turned off for universe N with the embedded command

c moritz universe N NoClip

The no clipping option only affects universes that do not fill lattices. It has no effect on the 2D and ray traced plots. Currently the option must be used for the 3D display of universes that fill multiple non-like cells or that fill more than 1 cell with transformations applied to the fill.

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