Dichroic filters - Can they be created in any Thea Render engine?

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SarahC
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Are these possible in the Material designer?
https://en.wikipedia.org/wiki/Dichroic_filter

I'm wanting to make this cube you see:
Cube-Prism-Cross-Dichroic.jpg
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Rombout
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Yes i believe so, i remember some post about this. Im not sure its 100% the same but i remember some post about this special glass.. Ill ry to find the post. BUt you are probably not able to see it
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Rombout
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okay found it, quite fast. its not exactly the same and its not possible in all engines using this mat. I did not read the complete thread again, there is a fresnal ramp used to create this effect.

BUt using some colored texture in the transmittance and reflection can fake a lot.
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tavolette_caustics_03.png
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tavolette_caustics_01.png
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Rombout
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I did a quick test using a custom gradient texture. You can make any effect than. You have way more freedome and its supported by by Presto. Though the lighting needs to be tuned so it looks like the example
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pbacot
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Can anyone share how this is done? We are trying to imitate a light sculpture that our client bought to go into a large dome. We may not be able to replicate the physical function but any ideas to get a workable representation will help. So far I took a photograph and used that as the transmittance image for a glass textured sphere with caustics in AMC rendering. I was surprised how it projected the image on the walls and dome, similar to the pictures from the artist--though it does not seem possible--the artist's picture shows a wall much closer to the sculpture.

Anyway I see the discussion here, but I don't see any link or description on how the texture was made, except something about a gradient.
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nigec
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Have you tried enabling Abbe Number in glossy glass? maybe turn it down to 12.5 ..
do you have a reference image of the sculpture?
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pbacot
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No I didn't try that. I'll check it out. Thanks
pbacot
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Thanks that gives some interesting results but I'll have to play with it and see what effects I get. Sorry I am told not to share the sculpture picture.
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nigec
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any picture of the desired result would help, it doesn't need to be the actual model, just something with the unlit glass and the effect once its illuminated :)
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pbacot
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Thanks,

It's like this. https://olafureliasson.net/archive/artw ... -wednesday (scroll down)
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