[vtkusers] Computational Geometry - user equations?

[Andrew Maclean]

vtkNamedColors was introduced in VTK 6. For VTK 5 you will have to specify
colours using RGB values.

e.g something like:
unsigned char red[3] = {255, 0, 0};
  actor->GetProperty()->SetColor(red[0], red[1], red[2]);

Andrew Maclean
On 4 Oct 2015 12:35 pm, "Gib Bogle" <g.bogle at auckland.ac.nz> wrote:

> Hi Piers, Andrew, Cory,
>
> This does not build with VTK 5.10 (no vtkNamedColors.h).  Is there a
> version that works with 5.10?
>
> Thanks
> Gib
> ------------------------------
> *From:* vtkusers [vtkusers-bounces at vtk.org] on behalf of
> piers.barber at logicmonkey.co.uk [piers.barber at logicmonkey.co.uk]
> *Sent:* Sunday, 4 October 2015 1:48 p.m.
> *To:* andrew.amaclean at gmail.com
> *Cc:* vtk
> *Subject:* Re: [vtkusers] Computational Geometry - user equations?
>
> Andrew, Cory,
>
> Thanks for the attachment - as a non-coder it bridged the gap between the
> PDF that I've seen before and what actually needed to be done.
>
> I've attached my trefoil knot code in a zip. The partial derivatives make
> a big difference to shadows.
>
> I'm on Arch Linux with VTK 6.1.0, and the only change I needed to make to
> get the example to build was to the CMakeLists.txt - so it picks up OpenGL
> rather than OpenGL2.
>
> I'm pleased that this works, but the output surface is rather jagged when
> compared to what I get with MathMod. Any ideas?
>
> For the VTK user list, the zipped files I mention are here:
>
> https://github.com/logicmonkey/curves/tree/master/vtk/TrefoilKnot
>
> ( unzip/git pull; cd TrefoilKnot; mkdir build; cd build; cmake ..; make;
> ./bin/TrefoilKnot )
>
> Thanks again for your help.
>
> --
>
> Piers Barber (-=:LogicMonkey;=-)
>
> On 2015-10-01 00:19, Andrew Maclean wrote:
>
> If I understand you correctly, then the approach described in
> http://www.vtk.org/img/ParametricSurfaces.pdfin " How to create your own
> surface" should work for you. If you adopt this approach, you just build
> using the library and you do not need to modify the VTK library.
>
> I attach  a VTK 6.3+ version of the example for you to try out.
>
> I'll add this to the VTK examples sometime next week.
>
> Once you get a surface you might like to look at:
>
> http://www.vtk.org/Wiki/VTK/Examples/Cxx/Visualization/ElevationBandsWithGlyphs
> and
>
> http://www.vtk.org/Wiki/VTK/Examples/Cxx/Visualization/CurvatureBandsWithGlyphs
> for some visualisation ideas.
>
>
> Regards
>    Andrew
>
>
>
>> ---------- Forwarded message ----------
>> From: Cory Quammen <cory.quammen at kitware.com>
>> To: piers.barber at logicmonkey.co.uk
>> Cc: "vtkusers at vtk.org" <vtkusers at vtk.org>
>> Date: Wed, 30 Sep 2015 09:15:45 -0400
>> Subject: Re: [vtkusers] Computational Geometry - user equations?
>> On Tue, Sep 29, 2015 at 12:13 PM, <piers.barber at logicmonkey.co.uk> wrote:
>>
>>> Hi All,
>>>
>>> I'd like to specify a surface f(u,v) in 3D with my own parametric
>>> equation system {x(u,v), y(u,v), z(u,v)}. And then visualize it.
>>>
>>> The only way I can see to do this is to add my function to the library
>>> source code, build the library and then call my function as described here:
>>>
>>>
>>> http://www.vtk.org/Wiki/VTK/Examples/Cxx/GeometricObjects/ParametricObjectsDemo#CMakeLists.txt
>>
>>
>> Yep, that looks like a good way to go.
>>
>>
>>> I'm using vtkParametricTorus[.h, .cxx] as a template, but is there an
>>> easier and more direct way to do this?
>>
>>
>> You can define your subclass of vtkParametricFunction in your local
>> project - no need to add it to VTK, which is what I think you were saying
>> above.
>>
>> Were you looking for a vtkParametricFunction subclass that takes an
>> expression for x(u,v), etc.? That doesn't exist as far as I know, but that
>> would be cool to have.
>>
>> Cory
>>
>>
>>> Thanks!
>>>
>>> -=:LM:=-
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>>
>>
>>
>> --
>> Cory Quammen
>> R&D Engineer
>> Kitware, Inc.
>>
>>
>> --
> ___________________________________________
> Andrew J. P. Maclean
>
> ___________________________________________
>
>
>
>
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