[vtkusers] Interpolating between scalars on a polydata surface

[Kevin Wilson]

Hey all,

I'm working on a program that colors a polydata surface based on point
values at sparse locations throughout the surface.  What I would like to
happen is to interpolate the scalar values between the points.  I've tried
using vtkProbeFilter (as shown below) but it sets the unknown scalars to
zero.

...
probe = vtkProbeFilter()
probe.SetInput(heartDataSurface.GetOutput())
probe.SetSource(heartDataPoints)

heartDataSurfaceMapper.SetInput(probe.GetPolyDataOutput())
heartDataSurfaceMapper.ScalarVisibilityOn()
heartDataSurfaceMapper.SetScalarRange(1,20000)
heartDataSurfaceMapper.SetScalarModeToUsePointData()
heartDataSurfaceMapper.SetColorModeToMapScalars()
...

I've also tried to reconstruct a suface from the points using
vtkSurfaceReconstructionFilter and then use the probe filter but the
surfaces don't match.

So, does anyone have any suggestions on how to interpret scalars on a
polydata surface when only a few are defined? or does anyone know how to
create a surface from a set of points but based on the shape of another
surface?

Thanks for your help,

Kevin