Re: [webgl-dev-list] Solid wireframe in WebGL

[Daniel Koch]

On 2013-01-22, at 10:43 AM, Alberto La Rocca wrote:

On Monday, January 21, 2013 10:02:57 AM UTC+1, Florian Bösch wrote:

WebGL does not have a lines drawing mode. However you can use standard derivatives and a specially prepared vertex attribute to draw a solid wireframe, see my blog post about it on: http://codeflow.org/entries/2012/aug/02/easy-wireframe-display-with-barycentric-coordinates/

Thank you, great article! I had considered the idea of discarding fragments too far from the edge of a triangle but not using fwidth to make line width constant.

I can see fwidth simply computes abs(dFdx(x) + dFdy(x))

How standard are dFdx and dFdy? Can one use them in case fwidth is not available?

dFdx, dFdy and fwidth all come from the same extension - OES_standard_derivatives, so you won't find one without the others.

As for popularity -- see http://webglstats.com

Daniel