[vtkusers] How color works

[Kenneth Porter]

I want to create a color-by-height image and I'm looking at this example:

<http://www.vtk.org/Wiki/VTK/Examples/Color_a_mesh_by_height>

I created this in ParaView by applying a Delaunay2D to my X/Y/Z point cloud 
of height readings off a surface:

<http://sewingwitch.com/ken/Stuff/HeightExample.png>

The scalar array that establishes the colors is presumably associated with 
each vertex. I'm guessing that each triangle can only have a single color, 
not a continuous shading from low to high scalar value. How does the color 
of each triangle get chosen?

To get a more smooth gradation, I'd guess I need to resample the surface at 
higher resolution to get more triangles, and then apply new colors to each 
triangle. I'd need to synthesize a new scalar array with intermediate 
values matching each triangle's "height". Is that true?