I recorded these lectures for students in the summer of 2010. A lot of things have changed since then, but I think they may still be interesting for people who study Houdini. Basically, these lectures were devoted to rendering and writing Mantra shaders by VEX in Houdini. I know quite a lot of VFX artists who used them for writing their own shaders and understanding how it works. Of course, these lectures are about the classical shading model, but the vector of development of Mantra is directed to Physically Based Rendering and I hope that we'll be able to write PBR shaders based on own bsdf functions in the next versions of Houdini. Unfortunately, I couldn't find time to translate them to English or make subtitles, sorry. But anyway, I hope these lectures will be interesting for you.