# Force a format in Sdf.Layer.FindOrOpen

**URL:** <https://forum.aousd.org/t/force-a-format-in-sdf-layer-findoropen/1739>\
**Category:** USD\
**Created:** [August 2, 2024, 4:04pm UTC](https://forum.aousd.org/t/force-a-format-in-sdf-layer-findoropen/1739 "2024-08-02T16:04:01Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![koen](https://avatars.discourse-cdn.com/v4/letter/k/a9a28c/32.png) [@koen](https://forum.aousd.org/u/koen)\
**Post date:** [August 2, 2024, 4:04pm UTC](https://forum.aousd.org/t/force-a-format-in-sdf-layer-findoropen/1739/1 "2024-08-02T16:04:01Z")

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Hello all,

Is there a way to force a file format independent of the file extension?

I tried layer = Sdf.Layer.FindOrOpen(“my\_usd\_file.blah”, {“format” : “usd”}) but that still gives a Cannot determine file format error.

Thanks,  
Koen

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**Author:** ![asluk](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.aousd.org/asluk/32/771_2.png) [@asluk](https://forum.aousd.org/u/asluk)\
**Post date:** [August 2, 2024, 4:48pm UTC](https://forum.aousd.org/t/force-a-format-in-sdf-layer-findoropen/1739/2 "2024-08-02T16:48:29Z")

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No, there would still need to be some sort of declaration of .blah as a file format plugin, and that plugin would need to be able to understand how to interpret file format arguments to dispatch to the .usd file format plugin, I think?

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**Author:** ![koen](https://avatars.discourse-cdn.com/v4/letter/k/a9a28c/32.png) [@koen](https://forum.aousd.org/u/koen)\
**Post date:** [August 2, 2024, 4:54pm UTC](https://forum.aousd.org/t/force-a-format-in-sdf-layer-findoropen/1739/3 "2024-08-02T16:54:27Z")

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Ok, that makes sense, I added my custom extension to the pluginfo json’s of all the usd installs, but I cant add this to the maya pluginfo, as the whole idea of a custom extension is to allow maya to use a different code path for some of our usd files ( we have some models that need a custom import path but we dont want to disable the default maya usd plugin as we use that in other scenario’s ).

Thanks,  
Koen