How to get flat shading (no phong, no gourand)

hamoid

I like my triangles :) What can I do to see them, and avoid smoothing between adjacent faces? I would still like the lights to be correctly calculated. Do I have to write my own shader for this?

hamoid

This is the closest answer I've found: http://ruh.li/GraphicsShading.html

OPENGL has a "flat" keyword to avoid interpolation. But I think Processing shaders are based on OPENGL ES 2.0, which means the only way to get no interpolation is to create triangles one by one, so they don't share edges. I'll keep searching.

Funny that the linked website says "Flat shading ... is useful for non-curved surfaces (like cubes), but looks bad otherwise". I find Gourand much uglier than flat :)

I wonder if I could get flat by messing up the normals...

mschi

this might be of help http://forum.processing.org/two/discussion/4699/face-normals-rather-than-vertex-normals-in-triangle-strip#Item_5

hamoid

Thanks for the link. I guess I have to read the source code of Toxiclibs to see how it's achieved there.

mschi

other option: draw each triangle seperately (no triangle strip)

hamoid

Yes, thanks, that's what I wrote above:

the only way to get no interpolation is to create triangles one by one, so they don't share edges.

plasmalasgun

How about defining the normal per vertex using two edges of the triangle to get a cross product and get a perpendicuar vertex to the given edges... instructions here: http://www.opengl.org/wiki/Calculating_a_Surface_Normal