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# 1 26-12-2008 , 10:29 PM
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Staggered triangulation of polygons... Possible?

Hi,

I noticed that Maya uses trapezoid (four sided) polygons. When triangulated (Polygons > Mesh > Triangulate) Maya simply splits each quad polygon into 4 sub triangles, like this:

user added image

However I'm trying to achieve a different effect, one which staggers the triangles:

user added image

The above was created in an obsolete rendering package for the Commodore Amiga (it's so old, it doesn't allow converting to 3DMax, Lightwave or Maya formats, and there are no third-party converters.)

I feel the latter is more elegant when you want to intentionally retain the polygonal 'facetted' appearance (for a crystal type effect), specifically the lovely helical/fibonacci-type spirals that make up the sphere. It also uses considerably fewer polygons than the non-staggered approach.

user added image

Any easy way of doing this within Maya?

# 2 26-12-2008 , 10:44 PM
gster123's Avatar
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I think what you may have there is the difference between the algorithms used previously and the ones used now, therefore i'm not sure if you can, without doing it manually (by modifying the triangulated one.


"No pressure, no diamonds" Thomas Carlyle
# 3 28-12-2008 , 03:22 AM
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and in that case you'll just have to write a MEL or python script to do it for you




that's a "Ch" pronounced as a "K"

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# 4 28-12-2008 , 10:13 PM
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I've found it's easy enough to fake, using a bit of maths.

Create sphere. Then Triangulate (Polygons > Mesh > Triangulate.)

Then switch to edit vertex mode, and grab the vertexes on each vertical layer and rotate them around 'en masse'.

The angles you rotate them depend on the number of sub-divs you originally used to create the sphere. I used 12 sub-divs (in other words 12 facets to make up the circumference) of my sphere, so the angle of each polygon was 360/12 = 30. I only wanted to rotate the layers by half a polygon so I divided this by two = 15º, which is what I used for the step-size.

Left the top layer alone, then grabbed and rotated the following layer by 15º, then the third layer by 30º, the fourth layer by 45º, etc...

Took all of 30 seconds to do.

user added image

user added image

I was wrong in my original assumption that it somehow used less polygons. It uses the same, just in a different arrangement. My error was when you triangulate the sphere you can see the polygons through the back at the same time, making it look like each trapezoid was split into four triangles and not just two.


Last edited by Timo79; 30-12-2008 at 09:58 PM.
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