Assignment 1

Installing pbrt

I built pbrt using VS2005 on XP. My first error came from spaces in the pbrt path. Another error came from incorrectly setting the VS Solution's path to OpenEXR. I was convinced at one point that the calls to Bison and Flex were missing a space, and that adding a space had fixed my build problems, but this since proven to be pure superstition.


I quickly grew tired of waiting so long for each 300x300 render to see the effects of my tiny changes. I decided to mock up my lighting in Maya, where I could position lights in real-time and get accurate renders very quickly. I used a sphere as a stand-in for the head. I continued using Maya to mock up my lighting for each of the four renders, copying the position and rotation of each object into the pbrt file once I was satisfied. The match was fairly accurate and from there I would manually tweak the pbrt file until I was happy. I noticed very quickly that only one of the cpu-cores in my computer would work on a render and took to working on two files at once: tweaking one while the other rendered or rendering both images at once. On the fourth image I finally realized the value of taking down the image resolution and samples per pixel for test renders.

Miscellany & Experiments

  • I did not realize until moments ago that we were supposed to try and match the sample images exactly. I used the the same lighting configurations but tweaked the look more to my personal preference than to matching the sample images. Generally, my images are more softly lit.
  • I was baffled by the coordinate system. The book declares pbrt to be left-handed but any change I made seemed more consistent with a right-handed system. I now suspect that my changes were in camera-space rather than world-space. Further experiments are needed.
  • I attempted to install a pbrt plug-in for Maya but it did not immediately work. The plug-in was built for a later version than I had on my PC. I will put more time into getting this working if it seems valuable for future projects.