Homework 1

PBRT Setup & Installation

The PBRT installation was trivial and easy on Mac OS X (10.4.3 / Build 8F46). I had to manually build and install libtiff to compile the exr tools (exrtotiff, tifftoexr etc). This was also relatively painless. I had to slightly tweak the typical configure based buid cycle (configure, make & make install) to build libtiff on OS X but I found directions online for this and didn't run into any problems. I also downloaded and built OpenEXR, only to later realize that Preview displays exr files and so I could view the files using the Mac Finder.

Process & Observations

I had read about the Camera space coordinates in the book and so didn't have any difficulty setting up and positioning lights. However, I did find configuration 1 tedius to reproduce since I had to reduce the cone angle to keep the backdrop from showing (I actually don't understand why the sample image is setup this way since the assignment handout made no mention of this). Configuration 2 was straightforward to setup. For configuration 3 it took me a few tries to figure out what parameters to use for my fill light so that the image would not be overexposed. Configuration 4 was reasonably tricky because we also had to figure out which lights were spot lights and which were area lights. It was obvious that the fill light should be an area light and the accent light a spot light. However, the other two lights could spot lights or area lights and I couldn't decide one way or another looking at the sample images and the results I was getting. I was getting fairly close results with just spot lights for these types so I stuck with them.

Results & some Extras

Here are low-resolution images that I created with different materials and configurations. I used blue plastic to come up with the "blue man" look; clay to produce a sculpted feel and a skin texture for the model and sky texture for the backdrop to see how much realism simple textures might add. Without subsurface scattering, hair and the oily sheen of skin, this last image still seems very fake. I tried creating the T2 liquid metal look and think the glass material worked pretty well. Finally, I thought I'd try to use a photon integrator and produced some images showing direct, indirect and caustic photons. The last 3 images show these effects. The first in the set is produced without photons, the second has indirect & direct photons and the last has caustic photons only.

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