[vtkusers] Parametric representation of a surface.

Andrew J. P. Maclean a.maclean at acfr.usyd.edu.au
Wed Jun 19 20:12:53 EDT 2002

Has anyone any ideas on how to visualise the parametric representation
of a surface? Currently I create a vtkPolyData structure containing the
points (x,y,z) and normals and sample this using vtkImplicitModeller. I
also set the scalars to 0 because this represents the surface (I think
that it is correct) - this step may not be necessary.

Problems appear when I contour it. It seems that I can only extract a
surface lying outside (in the direction of the normal) of the points.

I thought that something like:

Cf->SetValue(1,0) would extract the surface (where cf is the contour
filter) but this does not work.


I can use Cf->GenerateValues(2, -maxDist, maxDist); where maxDist is a
small value, but the rendering of the surface is critically dependent on
the value of maxDist. If it is too small then a surface is generated
with missing triangles and if large, then surface moves away from the
points. But this generates a surface with a finite thickness. I am using
SetMaximumDistance(maxDist) and SetAdjustDistance(2 * minDist); in the
implicit modeller.


Has anyone any ideas on how to get a surface whose "thickness" is 0?





Andrew J. P. Maclean


Australian Centre for Field Robotics

The Rose Street Building J04

The University of Sydney  2006  NSW



Room:  106

Phone: +61 2 9351 3283

Fax:   +61 2 9351 7474





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