Hi All I have put up an album of truncation animations http://www.antiprism.com/album/815_truncations/imagelist.html The scripts I used to make the animations...
... I have added in the two truncation animation scripts, a rotation animation script, and a script to make polyhedral helixes. The last one is not in any way...
Hi, Deducing faces may be a bit of a trick. Consider the compound of 5 tetrahedra within a dodecahedron. We can take pairs of vertices and find the diagonals...
Hi Roger ... If you look at the vertex figure of the possible faces then it is a compound of two triangles. Where you have compound vertex figures you could...
Hi Adrian, ... One way or another I believe the vertex information is quite often needed if I am to go about it this way. I was hoping to find the faces by...
Hi Roger I am still reviewing the documentation. In the snapshot I labelled conway -c as -M, which I have fixed. I noticed in conway the string is processed...
Hi Roger ... I have just had a look a George Hart's "Harman's Compounds" page and I don't really follow the restriction on having mirror symmetry. Having...
Hi Adrian, ... I was using -M to match canonical then realized I needed -M for map. ... Actually I put in the -r option for fun. What happens when the ...
Hi Roger ... I have just received your updated version. The help for option -r says "execute operations from right to left". I will change this to -r...
Hi All I have just released Antiprism 0.17 http://www.antiprism.com/download This release includes Roger's program for Conway Notation (which is adapted from...
Hi All, I updated the Uniform Compounds page. I changed from Stel files to OFF files so non-Stella folks will be able to open them, but OFF files can still be...
Hi, Recently a release of Stella came out in which the colors over overlapping faces could be blended. This looks very nice with some of the uniform compounds....
Hi Roger ... It may not be too difficult, and may not be especially computationally expensive for normal cases. The polyhedra are normally triangulated anyway...
Hi Adrian, ... This is the part that I would think would be non-trivial! ... Of the Uniform Compounds the VRML files have cases where this a bit of shimmering....
Hi Roger ... The third face is just more triangles, and OpenGL will triangulate the overlapping/non-overlapping regions, so the only non-trivial thing is to...
Roger, ... Actually the code to do this was developed from scratch and not dependent on the existing stellation code. You'll notice that stellation is not...
Hi Rob, ... Now that you mention it, blending does work without being able to stellate. But the planes must have to be very close together to count as...
Hi Adrian, ... http://www.georgehart.com/virtual-polyhedra/compounds-harman.html This is one of the pages I sited for the Uniform Compounds. This has been a...
Hi Adrian, I think the foremost problem with symmetry is to be able to detect symmetry in the first place. I once talked to Chris Lomont who wrote the...
Hi Roger ... This is a good find! I had in mind the Waltzman method 3.2.1 (with the initial axes to test being found for the convex hull). Having flicked...
... Say the compound symmetry matrix set is S and there is a polyhedron with symmetry matrix set P. First find the matrices common to P and S, call the set K...
Hi Adrian, I noticed the citation list at the bottom talks about other polyhedra algorithms. I look for these kinds of things from time to time. Digging around...
Hi Roger ... Whenever two planes of mirror symmetry meet their intersection is an axis of rotational symmetry. In the case of a right regular pyramid the...
Hi Adrian, ... But I was looking for code to detect mirror symmetries (reflections). If a polyhedra is chiral there will be no mirror symmetry. So a polyhedra...
Hi Roger ... If you have one mirror then you have them all, so it can be done by checking once for a mirror in the plane of two 5-fold axes. This would be done...
Hi Adrian, Now that Antihedron can color explicit edges and vertices, something practially every other Geom project can't do, there are some unique things that...
Hi Roger ... That should be doable at a later stage, and would be useful. ... It is easy to add in. What sort of models do you think would use the colouring? ...
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