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FluidEdge
05-21-2009, 09:22 AM
Hi,

Is there ANY way to render curves in MR in the same way that Renderman does it?

I've got a hair simulation going that needs rendering, however the paint effects renders look really bad and Shave and a Haircut isn't an option.

We could potentially wheel out Renderman, but i'd much rather render with Mental Ray.

So are there any curve shaders/mel scripts that will do this.

What is an alternative to rendering Hair without paint effects?

Is the p_HairTK shader any help here or is it only to be used with Fur/surfaces?

haggi
05-25-2009, 10:32 PM
As much as I know the paintfx hair rendering uses mr hair primitives. So the rendering should be quite good at least with the rasterizer.

The problem is that you cannot assign your own shader. But I think there is a geometry shader which enables you to assign an arbitrary shader to objects. I think pupped has such a shader...

FluidEdge
05-26-2009, 09:23 AM
I think we might go with paint effects as i've come up with a look that we're fairly happy with. However im still looking into using MR curves.

The Puppet Shaders have a "p_shader_replacer" in the geometry shaders and a "p_HairTK" which is just a material shader.

I can't see a way of linking the two unfortunatly. If I were doing this with Fur it would be straightforward as there is "something" to shade. A curve doesn't lend it self to this unfortunatly. There would be no options for setting base/tip width either.

No i'm afraid it's another example of where Mental Ray just plain sucks. Autodesk really should start looking at other options for it's premium renderer. A Renderman compliant renderer would be a dream. It's not as if we don't pay enough for the software.

leif3d
05-26-2009, 11:37 AM
I'm not sure how you have to integrate the shot, but you may want to take a look at rendering with 3Delight, the new version is just out (I haven't tried it yet, but it supports the latest version of Maya) and I'm not sure if you know, but the first two CPU threads are free and can be used as a fully commercial license.

You should be able to render the curves separately with their respective AOV's (shadow, indirect spec, indirect diffuse, etc...), in order to integrate it into the rest of your MR renders.

Good luck.

FluidEdge
05-26-2009, 12:49 PM
I've heard about 3Delight before. I was looking at their website just yesterday in fact. I perhaps wasn't looking closely but i thought it cost ~$1000 per licence?

If there is a free version i'd be keen to try it out for a few scenes to see what it can do.

Thanks for the tip.

leif3d
05-26-2009, 02:08 PM
3Delight website says the following:

"The first 3Delight license is free of charge"

"For all additional licenses:



The cost is 1,000 USD for a two threads license and 1,500 USD for a four threads license."

Here is the link:

http://www.3delight.com/en/index.php/products/3delight/3delight_pricing_and_licensing

Good luck.

haggi
05-26-2009, 10:10 PM
However im still looking into using MR curves.
No i'm afraid it's another example of where Mental Ray just plain sucks. Autodesk really should start looking at other options for it's premium renderer. A Renderman compliant renderer would be a dream. It's not as if we don't pay enough for the software.


Okay. You are right, prman as well as 3delight are really fine.
But all these dont help if the translation is not as good as you expect.

Mentalray is really a reat piece of software. It renders curves without problems - millions of them. AND if you use paintfx hair - they are translated into mr native curves.

What about using painfx hair? You can set base/tip width and with the puppet geometry shader and the puppet hair shader you should be able to do a fine rendering.

I didnt use the puppet shaders yet, but as always a geometry shader has to be connected to a simple renderable standin geometry. Then I suppose you will have to give it a geometry name of which the shader should be replaced.

leif3d
05-26-2009, 11:37 PM
AND if you use paintfx hair - they are translated into mr native curves.


That looks to be the solution right there.:thumbsup:
It would be nice to see the progress.

FluidEdge
05-27-2009, 08:08 AM
i'd never thought about using the puppet shader with paint fx.

I'd need:

p_shader_replacer assigned to a unit cube, with p_HairTK as the material and the paint effects hair as the object?

Also a p_HairTK_shadow plugged into the shader replacer too?

I've tried this before and couldn't get the hair_shader to affect the colour of the fur/hair.

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