[vtkusers] What datatype to use to represent ordered point clouds

[Øystein Skotheim]

Hello. I am working with 3D data from a structured light instrument.

My structured light instrument returns an organized point cloud as a
matrix of 1280x960 (x,y,z) values. I have also an associated contrast
value and an intensity value for each point. Some of the (x,y,z) values
might be invalid because the contrast was too low to obtain a valid data
point at this point (hence they should not be visualized).

The x and the y coordinates are set up in a "warped" regular grid
(because of barrel or pincushion distortion in the camera)

Up to now I have been using vtkPolyData to represent my data. I insert
all the valid points, and then I create one cell of type VTK_VERTEX for
each data point. However, then I lose the nice structure of the data.

Which is the correct datatype to use for me. Is it better to use
vtkStructuredGrid with a "blanking" filter for the invalid points? What
are the pros and cons of using vtkStructuredGrid instead of vtkPolyData?
How do I visualize a vtkStructuredGrid as a cloud of points?

Thank you! :-)

-- 

Øystein Skotheim
Scientist, Optical Measurement Systems and Data Analysis
SINTEF ICT [http://www.sintef.com/omd]