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ModelImporterMeshCompression docs could be more clear

Discussion in 'Documentation' started by Xarbrough, Feb 22, 2017.

  1. Xarbrough

    Xarbrough

    Joined:
    Dec 11, 2014
    Posts:
    1,188
    https://docs.unity3d.com/ScriptReference/ModelImporterMeshCompression.Low.html

    Nice to see, that we get info about the implemention, however I find it relatively unclear, what exactly the given information means.

    I understand that vertex positions will be quantized to 20 bits per component, however, what is component referring to and what are the implications of this? Does it mean, that vertices will be stored in a structure (like Vector3) that takes up 20 bits as a whole or does each vector component, x, y, and z take up 20 bits individually? Maybe the docs could also include what this means for mesh size and the accuracy of data.

    Is the accuracy of vertex positions dependant on the local or world size of the object? Does pivot position influence anything?

    We are seeing some unexpected behaviour with this feature, and are having difficulties tracking down the exact cause, other than mesh compression causes mesh deformations.

    Secondly, about https://docs.unity3d.com/ScriptReference/MeshUtility.SetMeshCompression.html we saw, that the compression can be applied to meshes, which are stored in the scene during edit time. The values are correctly applied and written to disk when saving, but in case there are visual differences because of compression, those differences only show, when the scene is reloaded. It looks, like the mesh representation in the scene is only updated when a model is imported, but in this case, it's stored in the scene and only gets updated, when the scene is reloaded. We'd be happy to see something mentioned in the docs, or else I might need to submit a bug report, if it's not intended.

    Thank you! :)