[vtkusers] Depth buffer

[Ken Martin]

There are a few issues that can cause z fighting or what looks like z
fighting.  If your data is away from the origin then you may hit floating
point issues. For example if your data ranges from 5001 to 5003  the ratio
of the distance to the size is large enough to cause float point resolution
issues (aka 5002/2 = 2501)  If using the OpenGL2 backend you can use this
topic in VTK to automatically address that problem

https://gitlab.kitware.com/vtk/vtk/merge_requests/2797

If that is not the case then it could be that you have identically located
surfaces. In that case you need to use the local offset methods in Mapper
to set one of the mappers to be behind/in front of the other.

You can also try tightening up the default zbuffer expansion using

renderer->SetClippingRangeExpansion(.1)

which is tighter than the default of 0.5 and will waste less resolution
typically.

Thanks
Ken


On Wed, May 17, 2017 at 6:15 AM, Rustem Khabetdinov <
rustem.khabetdinov at gmail.com> wrote:

> Hello,
> I am having troubles with z-fighting. Is there anything that can help
> reduce this? I found out that it is possible to increase depth buffer
> precision or change near plane. As far as I know we are not allowed to
> change near plane values. Is there any information on what precision is set
> by default or where I can change that?
>
> Best Regards,
> Rustem
>
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-- 
Ken Martin PhD
Distinguished Engineer
Kitware Inc.
28 Corporate Drive
Clifton Park NY 12065

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