White polygon faces with black edges?

[Benjamin Drucker]

I'm trying to show some shapes with a base color of white (easy) but with black lines on all triangle edges.  I saw how to get wireframes, at least with v0.8, but I want opaque sides.  Any ideas?

[Rehno Lindeque]

Probably you'll need to add the geometry twice - once for the faces and once for the wireframe. Be cautious of z-fighting though, might need to use a shader to add some bias to the z-component there.

[Rehno Lindeque]

PS actually come to think of it webgl doesn't allow you to write to the fragment depth, you'll need to add the bias in the vertex shader.

[Benjamin Drucker]

Rehno, that sounds perfectly plausible. However, I am too noob to
understand what you said.

I have read through about half of the lessons at learningwebgl
(http://learningwebgl.com/blog/?page_id=1217) and that's about all I
know of webgl. I'll dive in to it a bit further, but if you know of
an example of doing something related to what I'm targeting, I'd
appreciate a link.

Cheers!
Ben

[Lindsay Kay]

I think Rehno's just talking about how the solid faces and the
edgeshave to be separate geometries, and how you'll want to ensure
thatthey don't clobber each other's pixels in the Z depth buffer
(depthfighting), so you'd want to have the edges offset a little bit
fromthe face extents.
On 18 October 2011 18:50, Benjamin Drucker

[Benjamin Drucker]

I was hoping to do this with a fancy custom shader.  I need to do this in an automated way for any model I get.