[Sidefx-houdini-list] Anisotropic work around?
peter at basecampvfx.com
Sat Feb 18 09:46:21 EST 2006
I was hoping a kind soul could explain to me in somewhat plain English how
I can render anisotropic highlights when using polygonal surfaces containing
faces with less or more than 4 verts. I have tried to get my head around the
recent topic on sidefx.com, "creating a brushed metal shader". A few
technical explanations were given in vex code, which I'm embarrassed to say
is completely out of my league... I don't even know how to approach it...
most of the time I'm able to hack something together... but with vex surface
shaders I'm quite lost. While I would love to take the time to learn how to
program shaders in mantra, it's unfortunately an undertaking that requires a
great amount of time and playing around.
To me personally this is one of the areas in houdini which frustrated me the
most. Take the example of a default anisotropic highlight shader, it should
be able to render out a polygonal surface correctly, without the user having
to dig so deep as into vex code. It baffles me why there is no more detailed
explanation of this in the documentation. The line- "Avoid using the
Anisotropic Specular model on non-subdivided polygonal geometry because it
will look flat shaded." This is only partly correct as poly geometry built
with faces NOT quads, are rendered wrongly by the specular lighting model
anyway, even with the subd turned on.
Another issue for me is also why the rendered output from a subdivide sop, and
a polygonal model with 'Polygons as Subdivision Surfaces' turned on in the
render tab has different output. But that's another story...
Anyway.... back to banging my head against the wall... wohoo ;)
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