Orientation of UV at surface point p

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On 13/03/2004 at 02:42, xxxxxxxx wrote:

User Information:
Cinema 4D Version:   8.503 
Platform:      Mac OSX  ; 
Language(s) :   C.O.F.F.E.E  ;  C++  ;

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I have a channel shader which is using another shader as input.

It's easy to sample the secondary shader at the correct point. However, how can I retrieve the "orientation" of the UV-Map at my surface point p?

Thanks for any help!

Klaus

[Helper]

THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

On 13/03/2004 at 10:37, xxxxxxxx wrote:

Maybe could just drop a not if vd->GetDUDV() delivers the necessary information, so that n, ddv and ddu deliver the the needed matrix?

Thanks

Klaus

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On 16/03/2004 at 23:07, xxxxxxxx wrote:

ddu and ddv were on the right track... however, ddu and ddv are probably *not* necessarily perpendicular to each other, are they?

Kabe

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THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

On 18/03/2004 at 01:03, xxxxxxxx wrote:

The docs only say that they are perpendicular to the normal, so I guess they could even be parallel in pathological cases. What are you using the "orientation" for, and what do you mean more precisely by "orientation"?

[Helper]

THE POST BELOW IS MORE THAN 5 YEARS OLD. RELATED SUPPORT INFORMATION MIGHT BE OUTDATED OR DEPRECATED

On 18/03/2004 at 02:19, xxxxxxxx wrote:

By "orientation" I mean the UV-direction of the UV Map seen perpendicular to the normal n. I realized in the meantime that the direction could be generated out of ddu *or* ddv - though the result is often different.

BTW: Are ddu/ddv normalized?

Thanks

Kabe