# Flagpole actor with mpi does not render correctly.

**URL:** https://discourse.paraview.org/t/flagpole-actor-with-mpi-does-not-render-correctly/11064
**Category:** ParaView Support
**Created:** [December 22, 2022, 9:08pm UTC](https://discourse.paraview.org/t/flagpole-actor-with-mpi-does-not-render-correctly/11064 "2022-12-22T21:08:09Z")
**Posts on this page:** 4
**Page:** 1

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### Author: ![mclarsen](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/m/d07c76/32.png) [@mclarsen](https://discourse.paraview.org/u/mclarsen)
#### Post date: [December 22, 2022, 9:08pm UTC](https://discourse.paraview.org/t/flagpole-actor-with-mpi-does-not-render-correctly/11064/1 "2022-12-22T21:08:09Z")

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Hi All, I came to ask about an issue I am encountering that I suspect is a compositing issue. Specifically, I am using paraview egl 5.10.0-RC1.

I am using the flagpole actor for some annotations, but whenever I use MPI with more than 1 rank, the text of the flagpole actor disappears when there are no surfaces behind it (i.e., just the background).

Here is my reproducer script:  
[flagpole.py](https://discourse.paraview.org/uploads/short-url/lDvlW3sGfrXKrowYqUYkXKPm3ON.py) (3.3 KB)

running

```auto
mpirun -np 2 /usr/local/opt/paraview_egl/bin/pvbatch flagpole.py

```

 ![flagpole_2_ranks](https://discourse.paraview.org/uploads/default/original/2X/1/121560ae3cf93a364e2b1541b6190b7363fcf789.png)

```auto
mpirun -np 1 /usr/local/opt/paraview_egl/bin/pvbatch flagpole.py

```

 ![flagpole_1_rank](https://discourse.paraview.org/uploads/default/original/2X/e/ee89028737da13670fbfdebaefe64daeb09fa9ac.png)

Is this a known issue or can anyone think of a way around this? I also confirmed the same behavior with the desktop version (same release).

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### Author: ![Kenneth\_Moreland](https://discourse.paraview.org/user_avatar/discourse.paraview.org/kenneth_moreland/32/15033_2.png) [@Kenneth\_Moreland](https://discourse.paraview.org/u/Kenneth_Moreland)
#### Post date: [December 27, 2022, 8:31pm UTC](https://discourse.paraview.org/t/flagpole-actor-with-mpi-does-not-render-correctly/11064/2 "2022-12-27T20:31:25Z")

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I don’t know much about the flagpole annotation, but my guess is that when the text is being rendered, it is not being rendered into the depth buffer. That would cause the parallel renderer to think the pixels are really background and be discarded.

Someone with more knowledge about how the flagpole annotation is rendered would have to take a look at it.

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### Author: ![mclarsen](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/m/d07c76/32.png) [@mclarsen](https://discourse.paraview.org/u/mclarsen)
#### Post date: [December 27, 2022, 8:56pm UTC](https://discourse.paraview.org/t/flagpole-actor-with-mpi-does-not-render-correctly/11064/3 "2022-12-27T20:56:00Z")

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Thanks Ken. That is my suspicion as well.

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<div class="post-metadata">

### Author: ![mclarsen](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/m/d07c76/32.png) [@mclarsen](https://discourse.paraview.org/u/mclarsen)
#### Post date: [February 1, 2023, 11:09pm UTC](https://discourse.paraview.org/t/flagpole-actor-with-mpi-does-not-render-correctly/11064/4 "2023-02-01T23:09:35Z")

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Just so others know: apparently this is unique to pvbatch. Using pvserver works fine. I have no clue why there is a rendering difference between the two of them. Does anyone know why that might be the case?