Object Pascal version of C++ open source "Rasterrain" ray tracer based on original source code by Caleb Piercy from http://sourceforge.net/projects/rasterrain/
The process of implementing the original C++ version of the ray tracer has been documented on youtube here https://www.youtube.com/playlist?list=PLHm_I0tE5kKPPWXkTTtOn8fkcwEGZNETh
More information about the Object Pascal translation of the C++ code by Paweł Głowacki at http://blogs.embarcadero.com/pawelglowacki/2014/12/22/40419