surface deform operator fitting algorithm

["Matt Lind" <mlind(at)carbinestudios.com>]

Does anybody know how XSI fits an object to the UV space of a NURBS Surface when applying the surface deform operator?

 

Sometimes it makes an intelligent fit, other times it's complete crap.  I'm always using a polygon mesh with frozen transforms and operator stack, but the results are not what I'd always expect.  For example, using the default woman body that comes with XSI, rotate it -90 degrees on X, freeze rotations and 'Freeze M' to flatten it's operator stack. If deforming it to a nurbs cylinder (no end caps), I need to set scaling values of ( 0.5, 0.158, 0.5 ) in the surface deform operator PPG to get what I'd consider an intelligent fit.  Otherwise the woman is the Jolly Green Giant inside a blender.  I've noticed XSI tries to map the deformed object's center to UV coordinate ( 0.5, 0.5 ), but that's not always the case.  Ideally XSI would look at the entire woman's bounding box and fits that to the cylinder's UV parameter space.  For a visual of what I'd expect that to look like, using the same woman, set scaling to ( 1, 0.316, 1 ) and translation to ( 0, 0, 10 ).

 

I'd like to use this operator as a piece of a larger tool to map object(s) from one space to another en masse.

 

thanks,

 

 

Matt