# paraview parallel overlapping when raytracing and opacity \<1

**URL:** https://discourse.paraview.org/t/paraview-parallel-overlapping-when-raytracing-and-opacity-1/2768
**Category:** ParaView Support
**Created:** [October 15, 2019, 10:57am UTC](https://discourse.paraview.org/t/paraview-parallel-overlapping-when-raytracing-and-opacity-1/2768 "2019-10-15T10:57:59Z")
**Posts on this page:** 7
**Page:** 1

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### Author: ![gilcu2](https://discourse.paraview.org/user_avatar/discourse.paraview.org/gilcu2/32/2183_2.png) [@gilcu2](https://discourse.paraview.org/u/gilcu2)
#### Post date: [October 15, 2019, 10:57am UTC](https://discourse.paraview.org/t/paraview-parallel-overlapping-when-raytracing-and-opacity-1/2768/1 "2019-10-15T10:57:59Z")

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Hi, I am trying a parallel rendering with raytracing by ospray. When the opacity\<1 I get an overlapped image. I tried a clean to grid filter but the same result. What can I do?  
Thanks  
Reynaldo

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### Author: ![mwestphal](https://discourse.paraview.org/user_avatar/discourse.paraview.org/mwestphal/32/17_2.png) [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [October 16, 2019, 4:27am UTC](https://discourse.paraview.org/t/paraview-parallel-overlapping-when-raytracing-and-opacity-1/2768/2 "2019-10-16T04:27:56Z")

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Can you share a screenshot ?

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### Author: ![gilcu2](https://discourse.paraview.org/user_avatar/discourse.paraview.org/gilcu2/32/2183_2.png) [@gilcu2](https://discourse.paraview.org/u/gilcu2)
#### Post date: [October 17, 2019, 2:00pm UTC](https://discourse.paraview.org/t/paraview-parallel-overlapping-when-raytracing-and-opacity-1/2768/3 "2019-10-17T14:00:18Z")

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Here it is.  
Thanks  
Reynaldo

 ![overlapped_spiderman](https://discourse.paraview.org/uploads/default/original/2X/2/278bb4fd5228c1a850bca7f931f8c059f0338a07.png)

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### Author: ![mconti](https://discourse.paraview.org/user_avatar/discourse.paraview.org/mconti/32/2168_2.png) [@mconti](https://discourse.paraview.org/u/mconti)
#### Post date: [October 22, 2019, 12:26pm UTC](https://discourse.paraview.org/t/paraview-parallel-overlapping-when-raytracing-and-opacity-1/2768/4 "2019-10-22T12:26:54Z")

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Hey Reynaldo, OSPRay has a ton of issues when using parallel rendering (multiple processors). Try running this same thing using a single processor and see if you have the same issue.

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<div class="post-metadata">

### Author: ![gilcu2](https://discourse.paraview.org/user_avatar/discourse.paraview.org/gilcu2/32/2183_2.png) [@gilcu2](https://discourse.paraview.org/u/gilcu2)
#### Post date: [October 22, 2019, 12:28pm UTC](https://discourse.paraview.org/t/paraview-parallel-overlapping-when-raytracing-and-opacity-1/2768/5 "2019-10-22T12:28:23Z")

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In one processor works perfect.  
Thanks  
Reynaldo

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### Author: ![mconti](https://discourse.paraview.org/user_avatar/discourse.paraview.org/mconti/32/2168_2.png) [@mconti](https://discourse.paraview.org/u/mconti)
#### Post date: [October 22, 2019, 12:29pm UTC](https://discourse.paraview.org/t/paraview-parallel-overlapping-when-raytracing-and-opacity-1/2768/6 "2019-10-22T12:29:18Z")

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Glad I could help. I’ve run into this same thing multiple times.

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### Author: ![mwestphal](https://discourse.paraview.org/user_avatar/discourse.paraview.org/mwestphal/32/17_2.png) [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [October 25, 2019, 7:08am UTC](https://discourse.paraview.org/t/paraview-parallel-overlapping-when-raytracing-and-opacity-1/2768/7 "2019-10-25T07:08:08Z")

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Issue logged here :  
[https://gitlab.kitware.com/paraview/paraview/issues/19413](https://gitlab.kitware.com/paraview/paraview/issues/19413)