Individual faces change color based on position/orientation from camera?

# 1 11-09-2012 , 02:19 AM

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Join Date: Aug 2012

Posts: 22

Individual faces change color based on position/orientation from camera?

I guess this is the right category to post this question:

How would one take a polygon with all quads (I'm using a whirlpool-shaped funnel), and make each individual face render with a procedural solid color, to be assigned based on each face's relative distance or orientation to the camera?

I hope that's clear enough. I don't have much knowledge with expressions, MEL, or anything involving syntax, but I have a feeling it can be done somehow.

The result of this would presumably be, with a hi-res mesh, a smooth gradation of colors that change when seen through a moving camera, kind of the same coloration that you would see from a normal map - but dynamic.

Anyone have an idea how to do this?

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# 2 11-09-2012 , 04:24 AM

EduSciVis-er
Join Date: Dec 2005

Location: Toronto

Posts: 3,374

Does it have to be on a face by face basis? You can do stuff like this with the facing angle node... can't remember if it's its own hypershade node or if it's something like a surface info node. Give those a google.

-stwert

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# 3 11-09-2012 , 06:52 AM

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Join Date: Aug 2012

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@stwert:

I took your advice and found a pretty good suggestion here: https://www.3dbuzz.com/vbforum/showth...based-on-angle

(quote from the site)
"I'll describe the flow of nodes to the final Material: SamplerInfo Node (FacingRatio attr) > Ramp (Vcoord) Ramp (outColour) > Blinn (Colour) or surface shader (outcolour) if you don't want light to be a part of the result."

It's actually pretty simple to set up a quickie material that does this, but I'll need to spend some time seeing how much control it'll give me. Thanks for the suggestion, stwert!

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# 4 11-09-2012 , 12:10 PM

EduSciVis-er
Join Date: Dec 2005

Location: Toronto

Posts: 3,374

SamplerInfo node... that's the one. Getting precise control is all about adding nodes to nodes to nodes. Experiment with connecting stuff in different ways after you've got a basic color change based on camera angle.