# Backface Culling with PBR
**URL:** https://discourse.vtk.org/t/backface-culling-with-pbr/9547
**Category:** Support
**Created:** [October 7, 2022, 9:31pm UTC](https://discourse.vtk.org/t/backface-culling-with-pbr/9547 "2022-10-07T21:31:02Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@akaszynski](https://discourse.vtk.org/u/akaszynski)
#### Post date: [October 7, 2022, 9:31pm UTC](https://discourse.vtk.org/t/backface-culling-with-pbr/9547/1 "2022-10-07T21:31:02Z")
Hello,
Is there a way to disable backface culling with physically based rendering? It seems that whenever PBR is enabled within VTK, backfaces are culled regardless of the setting of `SetBackfaceCulling`.
Thanks!
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### Author:  [@lassoan](https://discourse.vtk.org/u/lassoan)
#### Post date: [October 9, 2022, 12:55am UTC](https://discourse.vtk.org/t/backface-culling-with-pbr/9547/2 "2022-10-09T00:55:38Z")
I haven’t noticed this until now, but indeed backfaces are never appear when PBR is used. This is a major limitation, but hopefully it is easy to fix.
@akaszynski it would be useful to submit a bug report to the VTK issue tracker. Maybe you could also have a look at the PBR rendering code, maybe the fix is trivial.
Until it is fixed, a possible workaround is to duplicate the polydata, use vtkReverseSense (to flip the face direction of all polygons), and append the result to the original polydata.
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### Author:  [@mwestphal](https://discourse.vtk.org/u/mwestphal)
#### Post date: [October 10, 2022, 2:30am UTC](https://discourse.vtk.org/t/backface-culling-with-pbr/9547/3 "2022-10-10T02:30:22Z")
I dont not see how this could be related. Did you try enabling backfaces with `BackfaceCullingOn` ?
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### Author:  [@lassoan](https://discourse.vtk.org/u/lassoan)
#### Post date: [October 10, 2022, 4:43am UTC](https://discourse.vtk.org/t/backface-culling-with-pbr/9547/4 "2022-10-10T04:43:56Z")
Even though backface culling is off, backfaces do not appear if PBR is used. If we switch to flat/Phong/Gouraud shading and leave everything else the same then backfaces appear as they should.
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### Author:  [@mwestphal](https://discourse.vtk.org/u/mwestphal)
#### Post date: [October 10, 2022, 4:45am UTC](https://discourse.vtk.org/t/backface-culling-with-pbr/9547/5 "2022-10-10T04:45:50Z")
Ok, an issue is needed indeed.
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### Author:  [@akaszynski](https://discourse.vtk.org/u/akaszynski)
#### Post date: [October 10, 2022, 9:29pm UTC](https://discourse.vtk.org/t/backface-culling-with-pbr/9547/6 "2022-10-10T21:29:15Z")
Added an issue to [https://gitlab.kitware.com/vtk/vtk/-/issues/18684](https://gitlab.kitware.com/vtk/vtk/-/issues/18684)
