Wednesday, August 10, 2011

[ Houdini Cookoff ] 03

Ok so today I spent time working on the camera track as well as getting the HDR assembled image to be orientated properly.

It has been a long while since I've done a camera track - you get professional trackers for all tracking needs as a vfx td ;-) and I think it is good enough for the cookoff. The LX5 thankfully records a .jpg thumbnail of the HD video with exif data - at 10mm. Given the crop factor of the lumix is 4.6875, I put in 46.875 into Houdini's camera and put 35mm as the aperture :P Seems to match the blu tacks quite well.
Once that was done, I put in a cg sphere, and dropped a reflection shader on it. This is a hand built (yeah yeah - its just a vop network) shader env map shader; basically using the fresnel vop to give me a reflection vector, that I then translate to world space and rotate about to match the reference plate. (Thank goodness I'd shot a few stills with the mirror ball in-frame)

It's not a perfect match, but I think close enough for reflection mapping and probably ibl. I'm thinking the mismatch is due to me shooting the sphere so close - I'd bet if it was shot at least 3-4 meters away - a physical impossibility - unless I broke down a wall - the results would be better. But oh well.

There is also a green tint in the CG render - I'm not sure why, but my wolfy intuition tells me it's most likely due to the florescent lights in the passageway. A little color correction will clear that up. Hopefully ;-)

Tomorrow, I hopefully will have time to create a matte object for the cup, as well as a model for the milk bottle. And texture it.

Given that I'm working in Houdini Apprentice, I'm set to render the maximum allowed - which is pal, at 768x576. The backplate is scaled down to a width of 768, and black bars put in to fill the empty space.

No comments: