On Mar 9, 7:55 am, Bo Schwarzstein <Bo.Schwarzst...@[EMAIL PROTECTED]
> wrote:
> 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 !
RenderMan likes left-handed coordinates. You can use "Ri_Orientation"
"lh" or "rh" to set you handedness.
|
