CGTalk - Renderman co-ordinates (s,t)?

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kpalazov

01-24-2003, 09:56 AM

HI all ,
I would like to say hello firstly to all the poeple here , this is my first time in the render forum.

Recently I began a study of renderman. The beast from the deep:)
Well to my surprise his not so big and not so deep. I have been writing shaders for a while now , and m very happy from the results I am recieving. But as always I have a small prob:)!

I still quite don't unstand the usage of surface co-ordinates-s,t and ss,tt.I realise there are points on the surface a my model but I have not been able to use them with function. Can anyone provide me with some insight in to the usage of these properties??

Why I am asking , is that I am trying to add localised detail. That is in a particualr part of the model isloate particular details. Say round loops around the leg area and straight edgings on the main body of a character , in one shader.

I would be very greatful if anyone can help me out on this subject as I realise that it is fundumental to the writing of a shader.And maybe share some example on the subject:)

Thankyou for your time

take care

Kiril

Fex

01-24-2003, 11:30 AM

trying to explain it:
"s" and "t" are default names for 2d texturecoordinates, that
were generated from projections, nurbs uv-mapping...
A rib-converter writes them as floats beside the vertex points of your object. In SL they are acessed by :
string ( texturename, s,t)
S and T could be any other float or could be manipulated in many
ways.

For your prob: don't remember how.. but Mtor could write out
your own (via Artisan) painted varying vertex floats, that could be used to mask, colorize and map textures in your shader.
If this doesn't work or is to complicated try a masktexture
map with provided default mapping like..

color CC = mix ( tex1, tex2, mask)

at last a classic link for SLwriting:
http://www.accad.ohio-state.edu/~smay/RManNotes/RManNotes.html
:bounce: :bounce:

kpalazov

01-26-2003, 11:36 AM

Thankyou very much
for your reply, for some reason right after I asked this question the answer popped up in my head. I guess, its the fact that until now I have looked at Rman the "the beast from the deep."

But anyways my thanks to you Flex , your answer is much appriciated. The paint vertex tool is outstanding and works just perfectly for what I want to do:)

Ofcourse being renderman I have other questions but I will leave them for time to solve;).

Thankyou again and take care

Kiril

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