Problem summary
When USD geometry with left-handed surface normal orientation is imported into Mari, it gets automatically converted into right-handed so that normals behave correctly. However, if the user subdivides the Object, the subdivided versions are created as left-handed.
Customer reported version
Mari 6.0v3
Steps to reproduce
Launch Mari and create a Project using a USD asset that has the orientation flag set to leftHanded.
Note: The attached .usd can be used.
Create a Surface Normal node and view it.
Note: This is not required to reproduce the issue, but it's the simplest way to visualise it. The issue also affects other aspects of Mari that use Normal data.
Expected behaviour
When viewed through the Surface Normal node, the asset should look the same with a Subdivision Level as it does at Level 0 (no subdivision):
Actual behaviour
The Subdivision Levels are using left-handed orientation:
However, Level 0 (no subdivision) is still using right-handed orientation.
Workaround
Unknown.
Reproduced by support
This bug has been reproduced in:
Mari 7.0v2 - Windows 10 - Rocky 9
Mari 6.0v3 - Windows 10 - CentOS 7
Unable to reproduce bug in:
Mari 7.0v1 - Windows 10 - Rocky 9
Mari 6.0v2 - Windows 10 - CentOS 7
Earliest version tested
Mari 6.0v3/7.0v2 - This feature (automatic orientation conversion) did not exist before this version
