# aliasing with visible cell selection
**URL:** https://discourse.paraview.org/t/aliasing-with-visible-cell-selection/2448
**Category:** ParaView Support
**Created:** [August 17, 2019, 9:51pm UTC](https://discourse.paraview.org/t/aliasing-with-visible-cell-selection/2448 "2019-08-17T21:51:19Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@banesullivan](https://discourse.paraview.org/u/banesullivan)
#### Post date: [August 17, 2019, 9:51pm UTC](https://discourse.paraview.org/t/aliasing-with-visible-cell-selection/2448/1 "2019-08-17T21:51:19Z")
When using the visible cell selection tool in ParaView on a fairly large mesh, the selection gets aliased if done from zoomed far out.
I actually noticed this in VTK with a custom application and figured I see if ParaView has the same issue which it does. Does anyone know of a way to work around this using the `vtkOpenGLHardwareSelector`?
Here’s a demo where I select from far out, observe the aliased selection, then make a selection while zoomed in which is not aliased:
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### Author:  [@utkarsh.ayachit](https://discourse.paraview.org/u/utkarsh.ayachit)
#### Post date: [August 18, 2019, 12:11pm UTC](https://discourse.paraview.org/t/aliasing-with-visible-cell-selection/2448/2 "2019-08-18T12:11:00Z")
This is indeed inherent to the implementation/design. It selects visible cells. If a cell has no contribution to screen pixels – which happens when you’re zoomed out – it is indeed not selected.
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [August 18, 2019, 4:42pm UTC](https://discourse.paraview.org/t/aliasing-with-visible-cell-selection/2448/3 "2019-08-18T16:42:39Z")
A work around it to use the select cells through, which compute a frustum and select all cells in this frustum.
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### Author:  [@banesullivan](https://discourse.paraview.org/u/banesullivan)
#### Post date: [August 27, 2019, 4:52pm UTC](https://discourse.paraview.org/t/aliasing-with-visible-cell-selection/2448/4 "2019-08-27T16:52:25Z")
Ah I see, thanks @utkarsh.ayachit!
@mwestphal - I wonder if there is a way that we could leverage the frustum and come up with some sort of way to only select cells that are traceable back to the camera… this might be a question better suited for the VTK discourse, but I’m curious if you think there might be a straightforward way to do this. Perhaps some sort of tracing within the frustum from the end of the frustum closest to the camera to the mesh in the scene?..
_Why?_ I’ve been working with high resolution meshes lately where I need to make selections over a large area but the keep running into this aliasing issue. Perhaps as simple solution would be to bump up the screen resolution?
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [August 27, 2019, 4:55pm UTC](https://discourse.paraview.org/t/aliasing-with-visible-cell-selection/2448/5 "2019-08-27T16:55:45Z")
That seems doable, but not straightforward.
In your specific case, you could extract the surface and clip in the middle, before using select cells through.