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Eden Exposito avatar image
Eden Exposito asked ·

Operators and displacement problem with Alembic file

Hello!


In the latest version of Arnold for Cinema 4D, I have been testing the shader application through operators. Everything seems to work fine, except for the displacement in alembic files.


As you can see in the screenshots, the result of the displacement applied to an alembic file added to an Arnold Procedural, is not correct. With native C4D objects and with an ASS file imported into an Arnold Procedural it seems to work.


All shader and displacement application is applied with the same operators diagram.


Can it be a bug?


The alembic was exported via C4D using File -> Export184013.jpg

184012.png

alembicoperators
184013.jpg (363.6 KiB)
184012.png (598.2 KiB)
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Peter Horvath avatar image
Peter Horvath answered ·

Sounds like a scaling issue. You have to take into account the Project Scale (in the Project Settings) and the Export Scale (in the Arnold Render Settings). By default the project is in cm, and Arnold operates in m.

For instance when you export a Sphere with 100 cm radius to Arnold, it will be 1 unit. When you export it to Alembic with 1 cm scale, it will be 100 unit.

The next thing is the Displacement Height which is a parameter on the Arnold polymesh. When you export to ASS, it exports the height from the Arnold tag with the proper scale. But Alembic does not know about this, so if you export to Alembic it will be loaded with the default 1 unit height. You have to set it with an operator considering the proper scale.

Hope this helps.

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Eden Exposito avatar image
Eden Exposito answered ·

Thanks Peter! you are correct!


With an override in scale solve the problem!


205417.png



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