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use intrinsic info in shaders

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hey guys,

do you know if it is possible to use intrinsic information in a shader? something like intrinsic:indexorder in a render state just like with packed attributes.

also, still in a render state, packed:primnum or packed:ptnum doesn't seem to be working. 

if i make an attribute in a wrangle on packed prims, let's say i@primid = i@primnum, and i call that in the shader with a render state it works as expected.

any idea?




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  • 9 months later...

I'm kind of wondering the same thing... was trying to write a shader that worked on both Poly and Volume geometry but checking "intrinsic:typename" doesn't seem to work in the material builder context.


Edit: looks like I can use Primitive Intrisic VOP, but that requires a filename...  whereas I'm trying to write a shader that can work on all geo.

Edited by Nicholas Ralabate
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as far as I understand this, renderstate packed can not lookup intrinsics and geometry global variables (@ptnum and @primnum). You can treat them like attributes at geometry level, but not at shader level as shaders have a different set of global variables (see Global Variables VOP - P, Pz, I, N, etc.), As you already found out, if you wanna import geometry globals or intrinsics into a shader it must be saved as an actual attribute with an arbitrary name. 

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Hi, in Mantra you can sidestep the problem with stylesheets and cvex for primitives. E.g.: Data Binding to intrinsic:indexorder

In this example, I'm targeting packed primitives themselves. If I would add subtarget: Primitive I could target individual polygons on a rubber toy. You can find some examples in the crowd section of the documentation.


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