[vtkusers] truncated cone as a polydata

[David Gobbi]

On Mon, Mar 7, 2011 at 4:25 PM, vlibertiaux <vlibertiaux at gmail.com> wrote:
> Hello everyone,
>
> I wonder is there is a *fast* way to produce a truncated cone as a polydata.
> The only way I can imagine to do this is to define a vtkConeSource and clip
> it with a vtkClipPolyData which needs to be defined through a
> vtkImplicitFunction.  In my algorithm (sampling of a volume with a truncated
> cone), I would have to recompute the truncated cone 100,000 of times (the
> direction will change at each step), which will be, I assume, time
> consuming.
>
> Is there any mean to produce such a polydata truncated cone ?

You can apply a perspective transformation to a cylinder.

But likewise, changing the direction of the cone should not mean that
you have to re-clip it.   You can clip it once and then use vtkTransformPolyData
to change its direction.

 - David