[vtkusers] vtkFixedPointVolumeRayCastMapper problem

[Heye ZHANG]

Dear all,

I run again one problem of vtkFixedPointVolumeRaycastMapper.

First

I generate
vtkImageData* id= vtkImageData::New();
id->SetDimensions(init_vtk3d.ndiv[0]+1,init_vtk3d.ndiv[1]+1,init_vtk3d.ndiv[2]+1);
id->SetScalarTypeToUnsignedShort();
id->SetNumberOfScalarComponents(2);
id->AllocateScalars();
id->SetSpacing(x_inc,y_inc,z_inc);
id->SetOrigin(x_start+length/2,y_start+width/2,z_start+height/2);
printf("origin:%lf,%lf,%lf\n",x_start+length/2,y_start+width/2,z_start+height/2);
unsigned short *ptr= (unsigned short*) id->GetScalarPointer();

then I use loop to initialize the "id":
  for(i=0;i<=init_vtk3d.ndiv[2];i++)
  {
   for(j=0;j<=init_vtk3d.ndiv[1];j++)
   {
    for(k=0;k<=init_vtk3d.ndiv[0];k++)
    {
       fread(coor_pos,3,sizeof(double),vtkcoor_handle);
       fread(ptr,1,sizeof(unsigned short),vtkdata_handle);
       if(coor_pos[1]<=-5)//---auck heart
        *ptr=0;

        ptr++;
       *ptr=*(ptr-1);
       ptr++;
    }
   }
  }
As I understand. I think 2 compoment data should be placed point by point in 
this way : compoment1 of point1,compoment1 of point1,compoment1 of 
point2,compoment1 of point2..... So If two components are the same, 
vtkFixedPointVolumeRaycastMapper should provide the same result as one 
compoment data.

those are other setting:
 volumeProperty->SetColor(color);
 volumeProperty->SetGradientOpacity(opacity1);
 volumeProperty->SetScalarOpacity(opacity);
 volumeProperty->SetInterpolationTypeToLinear();

 volumeProperty->SetAmbient(0.6);
 volumeProperty->SetDiffuse(0.6);
 volumeProperty->ShadeOn();

  volumeMapper->SetInput(id);

But finially I cannot get what I want.  the Geometry I want is inside a 
black box,but I think that black color should be transparent because I have 
set the opacity . I snap a figure and attach here. Please let me know you 
have a solution of my problem. Thanks 
-------------- next part --------------
A non-text attachment was scrubbed...
Name: untitled.JPG
Type: image/jpeg
Size: 15308 bytes
Desc: not available
URL: <http://www.vtk.org/pipermail/vtkusers/attachments/20060118/bc5b76c8/attachment.jpeg>