Triangulation and Convex Polygons

thomthom

what if... for each face with a hole in it one edge is drawn from the inner loop to the outer loop? (Even here there are cases where it could be difficult to do by script - for instance if there are multiple holes in the face.)

mrapsouthern

Got a solution in theory...

What I need is a plugin that will allow me to select a face with one (or multiple) holes in it and then divide that face in some way so that there would be multiple faces without holes.

i.e. for each hole in a face you only need to add two lines to split the face with 1 hole into 2 faces without holes.

Similarly,
a face with 2 holes requires 4 dividing lines and results in 3 faces with no holes.
a face with 3 holes requires 6 dividing lines and results in 4 faces with no holes.
a face with 4 holes requires 8 dividing lines and results in 5 faces with no holes.

This solution would mean you can represent a complex geometry with holes without splitting the whole model into triangles.

Is there anything already out there?

Thanks
Alex

MattC

Thomthom's idea should work great in case there is only one hole in a face, and if You make more vertices on the outside loop. The problem with 'spiky' triangles is that You have only 4 vertices to which the edges are drawn.

Assume that You have two sets of points:
[inner_vertices]
[outer_vertices] - for example 25 points per rectangle side

For every point from [inner_vertices] find closest point from [outer_vertices] and draw an edge between those two.

(Possible problem) when two outer points have the same distance to inner point. Which point to choose ?

Cheers
Matt

pilou

Can you post an image with result wished ?

thomthom

I was thinking one edge from inner to outer was enough - in order to reduce the number of faces.

But thinking of it more, ultimately everything breaks down to triangles, so if you have a polygonal face in SU - internally it'll be made up of many triangles. The same thing goes for any other software. So converting a face into it's internal triangles doesn't really make the model heavier - in terms of total number of triangles the graphic card needs to draw.