Pointiness falloff

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Egert_Kanep
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Joined: Tue Mar 13, 2018 10:34 am

Pointiness falloff

Post by Egert_Kanep »

Is it possible to control pointiness falloff? Right now it seems that multiplier slider only controls it's strength not size.
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B.Y.O.B.
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Re: Pointiness falloff

Post by B.Y.O.B. »

You can use a colorramp (aka Band node in BlendLuxCore).
It is in the utils -> band category in the material node editor.
Just slide one of the offsets to the left/right and you have non-linear falloff.

But maybe I misunderstand what exactly you want?
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Egert_Kanep
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Re: Pointiness falloff

Post by Egert_Kanep »

What I am trying to do is to make pointiness affect bigger area. In the attached photo I want to make pointiness go further down the slopes, but using band only increases contrast.
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pointiness_high_contrast.JPG
Racleborg
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Re: Pointiness falloff

Post by Racleborg »

Would adding a maths node give more control over the pointlessness effect, or possibly use Mapping to help position the effect. Sorry, I'm a bit new to this myself!
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B.Y.O.B.
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Re: Pointiness falloff

Post by B.Y.O.B. »

Pointiness calculation is a mesh preprocess step.
The surface curvature is evaluated and stored in the vertex alpha channel.
The preprocessing has no parameters: https://wiki.luxcorerender.org/LuxCore_ ... pointiness
So if you can't extend the radius with the band node, you're out of luck.

It is a crude thing to begin with (because it depends on the mesh density).
A much better solution would be a texture that is evaluated at render time (however this would also be much harder to implement).
Something like V-Ray Dirt: https://docs.chaosgroup.com/display/VRA ... C+VRayDirt
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