Hi everyone !
I am reading a paper names "Light Scattering from Human Hair Fibers".
In this paper it shows that everying is computed in right-hand
coordinate system, includes incident angle, azimuths in normal plane.
I have known that in renderman's surface shader, the dPdu,dPdv,Ng is
the local orthonomal basis, and it's a left-handed coordinate
system.as renderman. So How can I make a right hand coordinate in
surface shader if I want to use curve to represent the hair and fur ?
Use dPdu^dPdv or dPdv^dPdu ? or just using dPdv and forwarded N ?
How can I transform the vector into local coordinate ? just like cg
and glsl, just like this?
|Tx Bx Nx|
VinLocal = |Ty By Ny|*transpose( VinCamera )
|Tz Bz Nz|
I want to obain correct shading result, and I do not know whether the
different coordinate system will affect this.
Thanks very much !


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