[vtkusers] Asymmetry in color intentensity plot due to to triangulation

[Jan-Jaap van der Heijden]

I am trying to make a 2D color intensity plot from a vtkRectilinearGrid.

My first attempt was to extract polydata with a vtkRectilinearGridGeometryFilter, and then use a vtkPolyDataMapper2D to map this to the screen. This works, but a simple matrix like this:

  0 0 0 0
  0 1 1 0
  0 1 1 0
  0 0 0 0

gets distorted because each cell is converted to 2 triangles and the shading of the triangles causes asymmetry in this symmetric structure.

Next, I tried inserting cells of type VTK_QUAD into a vtkPolyData, expecting that these would be mapped to GL_QUADS, but I still see triangulation.

So, what is the recomended way to solve this? textures?

Regards,
	Jan-Jaap

-- 
Jan-Jaap van der Heijden, Software Engineer

PO Box 545, 7500 AM, Enschede, The Netherlands
TEL +31 53 4836460, http://www.phoenixbv.com/