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I wonder if maybe the Attribute node in Cycles can bring in a Custom Property of an object.

I have a model that has an LED light, and I wish I could change the color of the LED on different instances of the model, without using different materials.

Custom property

Atrribute node

unfa
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4 Answers4

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Since V2.92, Cycles and Eevee feature an Attribute Node.

Add a Custom Property to your object.

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Set the Type to Object and type in the name of your custom property.

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These objects share the same material :

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Gorgious
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An alternative to using the pass ID is using the object name and an OSL script. It is not very elegant either, but at least allows for setting multiple values. I have explained it here.

parclite
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  • I upvoted your post. However, including a summary of the method (copy paste it maybe) would be great. – Leander Sep 01 '19 at 16:50
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Use the object's pass ID.

That's a less than elegant, jerry-jigged way of doing it, but I've managed to animate the emission of some cartoon stars independently with this, even they're sharing the same material.

shader nodes

I collect the objects pass ID with the Object Info node, then perform some operations on it so I can operate under an arbitrarily defined range of 100 to 110. You can use any range you want. Notice I have only 10 different brightness levels on my shader. If you need something smoother, get yourself a wider range.

After doing that, it's just a matter of setting the object's pass IDs and the material will react accordingly on a per-object basis. You can even animate them by hitting I on the pass ID field.

This approach has lot's of limitations, though:

  • You'll waste some pass ID channels on this, and you'd better not use them elsewhere. Make sure you have them marked as used if you're on a larger project.
  • You have a single channel to transfer information, so no complicated things like colors can be properly and freely animated.
  • Also, the pass ID is an integer, and that means either using a large enough range if you need fine detail or going for a coarser animation.

But it's the best I've found until now.

Fernando D'Andrea
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There's a patch that adds exactly this functionality in the works:

https://developer.blender.org/D2057

unfa
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