# FilteringSceneIndex plugin \_PrimsAdded

**URL:** <https://forum.aousd.org/t/filteringsceneindex-plugin-primsadded/1093>\
**Category:** Hydra\
**Created:** [January 6, 2024, 4:22am UTC](https://forum.aousd.org/t/filteringsceneindex-plugin-primsadded/1093 "2024-01-06T04:22:41Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![paoloemilioselva](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.aousd.org/paoloemilioselva/32/267_2.png) [@paoloemilioselva](https://forum.aousd.org/u/paoloemilioselva)\
**Post date:** [January 6, 2024, 4:22am UTC](https://forum.aousd.org/t/filteringsceneindex-plugin-primsadded/1093/1 "2024-01-06T04:22:41Z")

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First of all, Happy new year everyone! 🙂

While writing an `HdSingleInputFilteringSceneIndex` plugin I’ve noticed that I don’t get any `_PrimsAdded` call when loading a file with `UsdStage::Open(...)`, in my simple viewer, and I only get `GetPrim` and `GetChildPrimPaths` calls.  
I do get it thou when I add a new prim, while the viewer is running.  
Also, I get the `_PrimsDirtied` for the camera, when moving it around.  
I’m using `UsdImagingGLEngine` in the viewer.

But if I run my plugin in usdview, I get `_PrimsAdded` and all others `_Prims*` calls.

I assume this is based on how I’m loading the stage, and before I get deeper in the source code, I wanted to check if there is anything obvious I should look for.

Cheers!

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<div class="post-metadata">

**Author:** ![paoloemilioselva](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.aousd.org/paoloemilioselva/32/267_2.png) [@paoloemilioselva](https://forum.aousd.org/u/paoloemilioselva)\
**Post date:** [January 6, 2024, 4:29am UTC](https://forum.aousd.org/t/filteringsceneindex-plugin-primsadded/1093/2 "2024-01-06T04:29:45Z")

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oh… and I just needed to “rubberduck” this with the forum…

Note to self: make sure your cmake file updates all install locations…

Nothing to see here, all is working as expected!

Thank you!