# how to rendering volume and transparent polygon together with a correct order?

**URL:** https://discourse.vtk.org/t/how-to-rendering-volume-and-transparent-polygon-together-with-a-correct-order/8599
**Category:** Support
**Created:** [May 26, 2022, 12:56am UTC](https://discourse.vtk.org/t/how-to-rendering-volume-and-transparent-polygon-together-with-a-correct-order/8599 "2022-05-26T00:56:42Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![SnowWindSaveYou](https://discourse.vtk.org/user_avatar/discourse.vtk.org/snowwindsaveyou/32/5223_2.png) [@SnowWindSaveYou](https://discourse.vtk.org/u/SnowWindSaveYou)
#### Post date: [May 26, 2022, 12:56am UTC](https://discourse.vtk.org/t/how-to-rendering-volume-and-transparent-polygon-together-with-a-correct-order/8599/1 "2022-05-26T00:56:42Z")

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after i set the opacity value for my polygon, the volume will always rendering above the polygon.

used vtkPolyDataMapper & vtkGPUVolumeRayCastMapper