[vtkusers] List of specific queries:

[Mathieu Malaterre]

James,

> Lighting:
> I am trying to display the element material information for a finite element
> mesh. I am denoting each material with a (slightly) different colour. I have
> an automatic colour generation method that I implemented before when using
> the RenderWare (games) graphics library. However, in many instances some of
> the colours are indistinguishable. I believe that this is a lighting issue.
> I am using vtkLight s as I tried to use a LightKit and it didn't work. Any
> suggestions?

No clue...

> StreamLines:
> I am using the vtkStreamLine object (along with a vtkTubeFilter) to create a
> streamline emanating from a user-defined point. Because the flow magnitude
> can sometimes be extremely low, the program "locks up" or hangs trying to
> generate the streamline. Are there any simple settings or checks that I can
> do to predict that this will happen so as to avoid the hang?

No clue either...

> Quadratic Hexahedra:
> I am dealing with quadratic hexahedra (20 noded) finite elements. When I
> originally wrote the program VTK did not cater for these element types (I
> currently implement v4.0). However, I see now that v4.2 does have these
> element (cell) types. Are there any related or unrelated changes in VTK that
> could cause me problems if I convert to v4.2?  I assume that all the other
> probes (vtkCutter etc.) colour contouring will not be affected by this
> change (i.e. all I have to do is change the libraries and generate the new
> data required for the Quadratic Hexahedra elements and all the other
> functionality that I have written should work)?

Everything /should/ work. Please note that I did some fixes a few weeks 
ago to vtkQuadraticHexahedron (and some other vtkQuadratic cells). I 
would sugest you use VTK from CVS

> Vtk v4.5
> I see the latest build of VTK is being called 4.5. DO 4.3 & 4.4 exist. Is
> there any upside or downside to going straight to this version (rather than
> v4.2) besides the fact that it is not "signed off"?

vtk 4.4 should be available very soon in:

	http://vtk.org/files/release/

odd numbering refer to dvpt thus accessible through CVS only. Actually 
there is no particular branch/tag for odd number.

Also please note there has been some *big* changes from 4.0 to 4.2, and 
a few between 4.2 to 4.4 (float to double API change):

http://public.kitware.com/cgi-bin/vtkfaq?req=show&file=faq06.008.htp
http://public.kitware.com/cgi-bin/vtkfaq?req=show&file=faq06.011.htp

HTH
Mathieu
Ps: Again if you don't use a cvs client, you can use our web based at:

	http://www.vtk.org/cgi-bin/viewcvs.cgi

(look for 'Show files using tag:' and 'Download tarball')