For convenience, we have some pre-built renderers which you can download. That way you don't have to build them yourself. See Building Renderers.

For now, we are focused on OS X. We may add more platforms later.

OS X

PBRT

pbrt-v2-spectral with 32 spectrum bands spanning 395nm-715nm:

• http://color.psych.upenn.edu/rtb/downloads/pbrt.zip

Mitsuba

Mitsuba with 31 spectrum bands spanning 395nm-705nm:

• http://color.psych.upenn.edu/rtb/downloads/Mitsuba.zip

Mitsuba RGB (optional):

• http://color.psych.upenn.edu/rtb/downloads/Mitsuba-RGB.zip