View Full Version : texturing subdivision surfaces

04 April 2002, 06:36 PM
As a dedicated follower of nurbs I am breaking out into the brave new world of subd's.
CAn anyone help guide me through this mysterious land. A world of projections and unwrapped uv.s
I am using maya, DeepPaint with DeepUV and Renderman.

I can texture my model of a tree in maya ok as a polygon object however I have to convert it to subd's and render it in renderman. I am trying to use renderman subdivions surfaces though I have access to maya subd's too if they are any easier.

The main problem I have is twofold

One how the heck do I uvmap something as complex as a tree with hundreds of branches?. I can unwrap it in texture weapons or deep uv but am left with a right mess. I need to be able to paint bark texture on the model and have the bark foloow the direction of the branches.
When trying to get renderman to render it I seem to have to sew together the edge borders of every polygon to group the polys into neat sets. I then have to assign a renderman shading set to every group of polys and then assign the shader to each set.
It seems incredibly long winded and I am sure the wrong way to go about this..

any help greatfully apreciated!

04 April 2002, 07:51 PM

You could use the automatic texture mapping option in Maya, however there is a problem...

We recently had a bug logged with pixar (pre latest version) about it not been able to recognise where the UV map edges start and finish when you have an object UV map created with the automatic option.

I'm not sure if they have fixed this in the latest version.

Not sure if this is any help.


04 April 2002, 07:55 PM
Is this the same problem as I was outlining where by almost every polygon seems to get assigned an edge border. Unless these edge borders are sewn together renderman kind of sticks a copy of the file texture on each poly (by default) unless a shading set is defined.

Even doing all this I still end up with pretty crappy results. Especially when you have things like branches connecting to trunks at right angles.
I still dont understand fully how it calculates how the texture should wrap around these kinds of extreme joints...

In general though do I sound like I am on the right track or am I missing something fundamental?

The RAT docs seem to suggest the optimum way is to use projections and mtor coordinate systems. THis sounds impossible especially for something like a tree... how can this methodology work with using deep paint for instance??

05 May 2002, 09:07 AM

I know that with Maya When you Create a set of UV's for your pollys they Will transfer over to your Sub'd when converted. As for how to make them look good I have no Idea. I am going to listen to Leigh to learn how. She is the master :)) hehe

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