View Full Version : Clip maps and instances

Dan Ritchie
07-21-2017, 10:47 AM
A while back, I posted a series of articles on landscape rendering. I resisted talking about clip maps. My reasoning was something like this.

Transparency in LW is raytraced, hence clip maps can be faster than using transparency under normal conditions. Since instances are raytraced anyway, I surmised clip maps would have little benefit. I didn't want to talk about it, because I had no actual data go do on.

So my question is, has anyone done any time testing on raytracing instances with and without clip maps?

07-21-2017, 04:52 PM
Point one, transparency will cause you problems with reflection and specular, transparency channel alone will not properly exclude them, you also need to add a mask to these channels too, which is tedious, clip mapping on the other hand is a one stop solution and will work as advertised, that is why I personally prefer it.
Point two, excluding radiosity from clip mapped leaves on a bunch of instanced trees will do more to speed up the render than just clip mapping, never really seen any speed gain for clip mapping itself, go experiment.