instance color from attribute

Houdini Integrated Plugin

Moderator: juanjgon

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Ebo
Licensed Customer
Posts: 71
Joined: Sat Mar 11, 2017 9:36 am

Hi, I just wanted to ask if there is any possibility to color instance objects from an attribute on points. I would like to plug it into albedo or emission or use it as a scattering or absorption color with a medium node. Thank you.
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juanjgon
Octane Plugin Developer
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Location: Spain

Hi,

Yes, it is possible. If you have the "Cd" attribute in the points, you only need to use a conventional texture node configured to use the "rgb4k_map.ppm" texture file available in the plugin/tex folder, as you can see in the attached image.

Thanks,
-Juanjo
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2019-07-31 12_12_07-M__F-Octane_Houdini_development_HoudiniOctane_3.0_unit_tests_008-instancingCdCol.jpg
Ebo
Licensed Customer
Posts: 71
Joined: Sat Mar 11, 2017 9:36 am

Ou, did notice there is a special node for instances, thank you. How would you go about using Cd as an absorbtion or scattering color in NT_MED_SCATTERING node ?
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juanjgon
Octane Plugin Developer
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it is not a special node for instancing, it is the conventional texture image rgb node. I'm not sure, but I suppose that you should be able to use the same workflow to set the absorption or scattering in the instances.

Thanks,
-Juanjo
rohandalvi
Licensed Customer
Posts: 169
Joined: Tue Apr 20, 2010 7:39 am

Ebo wrote:Ou, did notice there is a special node for instances, thank you. How would you go about using Cd as an absorbtion or scattering color in NT_MED_SCATTERING node ?
Hi,

Octane currently does not support textures in absorption or scattering. Only solid colors. 2019.2 just added that feature.

Regards
Rohan
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juanjgon
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Thanks, Rohan, yes, I've seen this new feature in Octane 2019.2. It is really cool! But in any case, I think that in this case the user wants a solid color from a Cd attribute, a constant value for all the object medium nodes, so perhaps the .ppm texture workaround could work.

Thanks,
-Juanjo
Ebo
Licensed Customer
Posts: 71
Joined: Sat Mar 11, 2017 9:36 am

Hi, It did not work. Thanks for working on it. :)
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juanjgon
Octane Plugin Developer
Posts: 8867
Joined: Tue Jan 19, 2010 12:01 pm
Location: Spain

Ok. Sorry about that. In this case, wait for Octane 2019.2 is the only solution, I'm afraid.

Thanks,
-Juanjo
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