[vtkusers] place arrows equally spaced along streamlines

[Cory Quammen]

Dan,

Actually, I think I'm wrong. I think you would get different
streamline results by changing the vector magnitudes. You'll
definitely get evenly spaced glyphs by normalizing, though :-) Too bad
the streamlines will be wrong.

I can't think of any other tricks using existing tools in VTK to do
this - you would need a scalar field along the streamline giving the
distance from seed point.

Cory

On Wed, Mar 15, 2017 at 9:20 PM, Dan Lipsa <dan.lipsa at kitware.com> wrote:
> Thanks Cory!
> This works very nice!
>
> Dan
>
>
> On Wed, Mar 15, 2017 at 12:08 PM, Cory Quammen <cory.quammen at kitware.com>
> wrote:
>>
>> Dan,
>>
>> Another way would be to normalize your vector field, run the stream
>> tracer on it, and then contour by integration time. That should give
>> you evenly spaced samples along the streamline when you run the
>> contour filter on it.
>>
>> A quick test of this in ParaView looks like it should work. See
>> attached images. The one with the normalized velocity field has even
>> spacing, the one with the non-normalized velocity field does not.
>>
>> Cory
>>
>> On Wed, Mar 15, 2017 at 11:44 AM, Dan Lipsa <dan.lipsa at kitware.com> wrote:
>> > Hi all,
>> > I would like to place arrow glyphs equally spaced along streamlines. I
>> > am
>> > using vtkStreamTracer.
>> > The only way I see to do this is to add an option to vtkStreamTracer to
>> > compute the distance from the seed and add this as a point data to the
>> > the
>> > streamline. Than, I can use contour to get the points where I need to
>> > place
>> > the arrows.
>> >
>> > Is there any other simpler way? Do you have any suggestions with this?
>> >
>> > Thanks,
>> > Dan
>> >
>> >
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>>
>>
>> --
>> Cory Quammen
>> Staff R&D Engineer
>> Kitware, Inc.
>
>



-- 
Cory Quammen
Staff R&D Engineer
Kitware, Inc.