[vtk-developers] FrustumSource face ordering is wrong?

[David Cole]

I wonder if it's just one of those philosophical/perspective
differences. If you think of the perspective view frustum, you might
think of visualizing it with just 4 pieces instead of 6, leaving off
the shapes for the front and back clipping planes. And then if you
look at it as it goes into the screen and fades to infinity, the part
you can see are the inside faces. I wonder if the original author
thought of it that way and considered the inside faces the "front"...

Or, it could just be an oversight. Or a bug. Or a feature.

Or somebody else whose history actually goes back that far will chime
in and enlighten us.


:-)

David C.


On Thu, Aug 17, 2017 at 7:30 PM, Bill Lorensen <bill.lorensen at gmail.com> wrote:
> Folks,
>
> This example colors the front and back facing polygons with yellow and
> red respectively. However you can see in the example that the red
> polygons are on the outside of the source.
>
> I have an MR that fixes the problem, but I want to be sure there is
> not some reason the faces are oriented the way they are now.
>
> Here is the example:
> https://lorensen.github.io/VTKExamples/site/Cxx/GeometricObjects/Frustum/
>
> Bill
>
> --
> Unpaid intern in BillsBasement at noware dot com
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