Subdivision Surfaces

[Steelrose]

I am working with Lightwave 3D and it has a great feature called Subpatching. I am also working on a program that will decode and use the lighwave data to create objects for openGL.

The question is this: does OpenGL have a method that will do the subpatching (I think it may be called subdivision patching or subdivision surfaces)? If so could you direct me to the site that has this information. The patching works well but when I freeze the object for OpenGL, I get thousands of polygons. I can render this but it causes alot of slowdown.

Thanks.

[JustHanging]

Hi,

Opengl won't do it for you, but if you really want to, you can always tesselate them by yourself. Google has a lot of links on this subject.

Oh, and then there's the extension, truform I think it's called, it does something similar to subdivision surfaces on hardware. ATI only.

-Ilkka

[This message has been edited by JustHanging (edited 02-11-2003).]

[Steelrose]

I was afraid of that. Oh well.

Thanks anyway for the help and I'll look into the tesselation.

[MichaelNewman]

If all you want is quadric subdivision (subdividing a quad into more quads), you could take a look at glMap*(). In general, there may be something helpful for you in Chapter12 of Red Book.

Your probably more interested in triangular subdivision, in which case you should read up a little one Bezier Triangles or the technology that trueform is based on PN Triangles.

[Steelrose]

Ok, I'll take a look.

Thanks