I watched the video from Mike Lyndon, and was wondering if the matcaps are available somewhere?

There's plenty around if you google image search for ‘matcap’. There's also several that ship with blender.

Thanks. That worked perfectly once I realized blender use hdr images and not jpg's. No wonder I did not find them at first.

what about creating matcaps in houdini… what would i have to do?

Like, if I had a nice looking shader set up, how can i bake it out with mantra? like maybe with the games baker tool? and then map it to a sphere? and then render that sphere…

somethin like that? right?

i feel like i'm missing details though… like, what exactly does the exr contain besides for color data?

Nothing, just colour data. The matcap material assumes you've rendered a sphere. It uses the normal of your surface to look up the correct pixel in your sphere render, and maps that colour back onto your model.