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Graphics > RenderMan interface > Local Coordinat...
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Local Coordinate Is Left Or Right Hand Coordinate System ?

by Bo Schwarzstein <Bo.Schwarzstein@[EMAIL PROTECTED] > Mar 9, 2008 at 06:55 AM

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 !
 




 2 Posts in Topic:
Local Coordinate Is Left Or Right Hand Coordinate System ?
Bo Schwarzstein <Bo.Sc  2008-03-09 06:55:24 
Re: Local Coordinate Is Left Or Right Hand Coordinate System ?
Felipe Esquivel <felip  2008-03-09 11:32:29 

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tan12V112 Sat Nov 22 12:51:44 CST 2008.