Hi,

I'm having some difficulty displaying scalar data. I have pared down my pipeline to these essentials:

vtkSFVolume8Reader <- I wrote this class myself to read in a volume from a

single file which stores values as bytes, it outputs

a structured points data set with unsigned char scalars

vtkImageThreshold <- Used to extract a certain tissue (the file being read in

is a segmented medical file)

vtkMarchingCubes <- I have ComputeScalars and Normals on

vtkPolyDataMapper <- ComputeScalars is On

vtkActor

vtkRenderer

vtkRenderWindow

vtkRenderWindowInteractor

I would like to read in a second MRI data file and use the values in that file to control the luminance of each point. I am planning on writing a filter class to do this and inserting it into the pipeline after I threshold the image (and I will add back in some filters to smooth the data).

Before I started to write this class, however, I wanted to make sure it would work like I wanted to , so I attempted to display the scalar data which was already in this pipeline. I thought that if I simply changed the SetInValue of vtkImageThreshold that I would be able to change the scalar values of the final object. No matter what I do, the actor is still blue (or a very dark gray if I have SetColorModeToLuminance turned on).

Does anyone know why this is occurring? Any help would be greatly appreciated.

Thanks, in advance,

--Chip