Making Triangles.

[Jason]

Hi all,

Does anyone know how "convert" to triangles reliably in the same way in a deforming mesh? The Divide SOP will divide into 3 faces for convex polygons but when a mesh deforms, different polys get judged convex and the topology changes.

I suppose I could convex a static mesh (the first frame of animation) and shift the points to animated positions... if I wasn't worried about transforming velocity attributes and such. But I am a bit worried.

Anyone have a good solution for this? Am I forgetting a simple SOP somewhere? This make me wish (again) there were some more tesselation tools in the Divide SOP - like bisect and such.

Thanks,

Jason

[sibarrick]

Here's how I do it, convex a rest version then use a point sop to move all the points to match the deforming one.

But since you are worried....

Use a polyreduce and set it to 100% and use the third input reference mesh.

[Jason]

Here's how I do it, convex a rest version then use a point sop to move all the points to match the deforming one. Convexing doesn't change the point count.

Or use a polyreduce and set it to 100% and use the third input reference mesh.

26412[/snapback]

Thanks, I'll try the polyreduce too- as I mentioned above, merely moving the points won't transform any velocity or normal (or any other vector) attributes properly unless I swap them back in from the destination geometry.

[sibarrick]

Yeah, definetely would be a handy extra option for the divide sop. Or in fact it should be one of the elements of divide that gets split out into a new sop.

Bricker could do with that too. Both could do with some additional functionality.

Either that or the convert sop should allow you to convert from polys to triangles, never did understand why it doesn't.

[Jason]

Yeah, definetely would be a handy extra option for the divide sop. Or in fact it should be one of the elements of divide that gets split out into a new sop.

Bricker could do with that too. Both could do with some additional functionality.

Either that or the convert sop should allow you to convert from polys to triangles, never did understand why it doesn't.

26415[/snapback]

Yesss.. I was so hoping it would.

I'd wish for some the following:

*/ Triangulate (strictly by vertex order)

*/ Bisect a triangle's longest edge.

*/ Tessellate

And it would be so nice to have these have conditions for iterations; for example: re-tesellate until "$AREA <= 0.01"

[FrankFirsching]

I usually use the TriStrip-SOP to generate the triangles followed by a convert-SOP to switch back to polygons. This also works for deforming geometry.

[Jason]

I usually use the TriStrip-SOP to generate the triangles followed by a convert-SOP to switch back to polygons. This also works for deforming geometry.

26417[/snapback]

Good idea, I'll try it too..