Hacker News new | ask | show | jobs
by chrisseaton 2228 days ago
How do you even render a quad? What if it isn't planar? Does it curve or crease?
1 comments
a_e_k 2228 days ago
In higher-end rendering, a quad that can be non-planar is called a bilinear patch. Yes, it can curve (cross sections tend to give parabolas), and while you won't get infinitely sharp creases you will get saddle-shapes.

See, e.g.: http://www.sci.utah.edu/~kpotter/publications/ramsey-2004-RB...

link
chrisseaton 2228 days ago
Wow seems like that’d be an order of magnitude or more slower to render bilinear surfaces rather than triangles. I wonder why they did that.
link