View Full Version : Pathtracing in LW part 2

Dan Ritchie
04-06-2015, 03:42 PM
I am getting back into using LW to do some basic pathtracing. I am making an effort to simplify my previous efforts.


Previously, I came to the conclusion that pathtracing is based on the idea that all illumination in a scene is an accumulation of all reflected light hitting a given spot. Basially, a pathtracer shoots out rays in directions decided by the BDRF, and accumulates whatever results are found at the end of the rays.

In path tracing, there are no light objects. All light comes from geometry, either reflected, or emitted.

To simulate this in lightwave, we turn off all lights, and use only the reflection parameter to control surface appearance. Previously, we scattered the rays using a micro-bump map. In this example, we are trying Lightwaves reflection blurring parameter instead.

A large blur value (say 1000) makes a surface very lambert in nature (light diffused in every direction) while a small or zero parameter makes a surface more glossy or reflective lookin


Dan Ritchie
04-06-2015, 04:32 PM
Here is the second part of the video

Dan Ritchie
04-07-2015, 03:31 PM

Playing with simulating a little chromatic aberration by adding an incidence gradient to the light object. very painterly results...

04-07-2015, 04:12 PM
This is cool. This is similar to the techniques that were used at Digital Domain(tm) for "Speed Racer."