RMAN problem.

[Symbolic]

Hi,

I am trying to render a couple of curves (poly) with render man.

When I set up the "ri_curveinterpolation" attributes in the RMAN output module... it renders ok. (kind of)

But when I try to define the attributes with an Attribute Create node (Detail, String, Linear) it renders a blank frame.

This is my first try with render man? Any ideas?

Thanks.

[Symbolic]

...And another wierd thing. The framing is wrong? It does not render exactly what the camera is viewing?

Cheers.

[Alanw]

It's hard to say without knowing what version and kind of RenderMan that you're using. Also, which version of Houdini?

For curves, I usually add the curve interpolation, step and basis parms to my geometry at OBJ level. The only real show-stopper is the lack of a hair procedural for prman like there is for Mantra, so that would have to be written if you're rendering hair.

[Symbolic]

Houdini 9.5.268

Render Man 14.0

Well... what about the SOP level detail attributes?

[Alanw]

Check out this thread. http://www.sidefx.com/index.php?option=com...t=prman++camera

I'm using 14.1 (as of today), but 14 hasn't given me any problems with the camera like 13.5 did in H 9.1. You should output RIB and see if your fov is messing up or perhaps something else. The only thing I can think of is the possibility of patched soho files or python scripts in your Houdini script path, or python path interfering with Houdini's rib generation.

SOP level attributes are usually bound to points. For curves, it's either "width" ,"constantwidth" or custom vars that speak to shaders, which you would declare with an AttribCreate SOP and then use the RenderMan tab on an Attribute SOP to bind them to your points in your RIB output.

The other time you'll need Ri attributes in SOP's is when you've got groups of points, primitives, verts, etc. that you'd like to assign different Ri parameters. ie. (Specular visibility, Diffuse visibility, Cs, Os, etc.) For that type of assignment you'll use the Properties SHOP in a Material Subnet. That will create shading groups in your RIB output.

If I got that wrong, and you're just trying to declare ri_curveinterpolation in SOP's instead of the other methods available, then I'm not sure honestly. I figure making it a type String, Primitive attribute would work, but maybe not.. There's really no need to declare attrib's like this which aren't bound to points in this manner when there's so many other injection points.

Hope that helps

Edited November 18, 2008 by Alanw

[Symbolic]

Thanks. Yes... this is exactly what I am trying to do. Instead of setting the Ri attributes on the Geometry at OBJ level... or setting them at the RMAN render module... I would like to set them at SOP level... with Attribute create.