Truncation animation

[gphillips]

Can anyone step me through how to show a morphing animation of the truncation of a polyhedron. e.g. The truncation of an icosidodecahedron to from a Truncated icosidodecahedron.

[robertw]

First worth mentioning that the truncation of an icosidodecahedron is not perfect: a true truncation will have rectangles rather than squares.

1. Load an icosidodecahedron
2. Select the net view (by clicking in it) and change it to the "Morph Duals by Truncation" view
3. You can interactively morph by holding Ctrl and the left mouse button and moving the mouse



4. Export the image/video by hitting "x" or this menu item:



5. Select the export options as you want them. Note: you can set the morph ratio to end on, eg 0.35 is roughly the truncated icosidodecahedron, but you can't bounce the animation unless you go all the way by setting the end ratio to 2.0. There's a slider to preview the animation before exporting.



6. Click "Export" and you're done.

[gphillips]

Thanks heaps! By the way - why is the "Truncated" Icosidodecahedron NOT quite a truncated model?
I can make a model with perfect Squiares, Hexagons and decagons. Is it just that it is not actually formed by true truncation?

[robertw]

The triangles and pentagons don't meet at square vertices. Cut any amount off and it will always be a rectangle. If you could "untruncate" the one with true squares, you'd end up with extra little edges where you were expecting vertices.

I think they went with the name anyway since it's a truncation in terms of the topology, the graph of faces and vertices, just not quite geometrically.

[gphillips]

Thanks for that. You (I) learn something every day! By the way, I reckon Stella is one of the most impressive programs in exiistence. Thankyou.

[robertw]

Thanks!