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4D Augment

Posted: Mon Jun 08, 2009 3:55 pm
by Major Mayhem
I would like to request an augment function for 4D polytopes.

Thanks.

Posted: Thu Jun 11, 2009 11:55 am
by robertw
Hmm, maybe someday. At least this would be easier than 4D faceting, which is more dependent on understanding the full symmetry of the model in question. Currently Stella doesn't really know the full symmetry of 4D models like it does for 3D models. Cell/face/edge/vertex types are all established based on various heuristics, but could still be wrong occasionally. Ideally you will (sometimes at least) want to augment to all cells of the same type at the same time.

The only problem then would be matching orientation between each one, but maybe this can also be based on a few heuristics (eg matching neighbouring cell types) and luck of the draw (in most useful cases I suspect there will only be one orientation anyway, and otherwise matching neighbours is probably enough).

Will also be a chore to remove any pairs of common cells.

Like I said, someday :)
Rob.

Posted: Sun May 19, 2013 11:21 am
by JMZuazola
Hi, Stella can't recognize 4d symmetry, but you can create an augumentation tool for 4d using:
1) augument selected cell.
2) augument cells of selected type.
3) augument cells with the same shape.

Posted: Sun May 19, 2013 2:08 pm
by robertw
Hi, I'm afraid the answer is much the same as it was 4 years ago. It will be a lot of work. No immediate plans but maybe someday.

Is there something you'd like to use it for in particular?

Posted: Sun May 19, 2013 11:33 pm
by JMZuazola
I want to make partial tetracombs.

Posted: Mon May 20, 2013 1:03 pm
by robertw
Hmm, well in 3D faces at which two polyhedra are augmented together are normally removed from the final model, though there's an option to leave both in as a duplicate face (leaving just one copy in would lead to a non-manifold surface, with potentially an odd number of faces meeting at some edges). I wonder whether the cells at which polychora are augmented should be removed or duplicated or something else?

Posted: Mon May 20, 2013 10:33 pm
by JMZuazola
Yes.