[vtkusers] vertex colors

[Dean Inglis]

I have a triangluar surface mesh with 
rgba color data associated with each
vertex (point) of the polydata mesh:

vtkDoubleArray* colors = vtkDoubleArray::New();
colors->SetNumberOfComponents(4);
for( int i = 0 i< nverts; i++)
  {
  colors->SetTuple4(i, r[i], g[i], b[i], o[i] );
  }

// where r,g,b,o are double precision red green blue and opacity values
// ranging from 0 - 1

vtkPolyData* surf =  vtkPolyData::New();
surf->SetPoints(surfPoints);
surf->SetPolys(surfCells);
surf->GetPointData()->SetScalars(colors);

How do I get the polydata mapper to use these
scalars to color the mesh?  Is it...

mapper->SetInput(surf);
mapper->SetScalarVisibilityOn();

? I'm not getting what I expect.

thanks,
Dean