[MINC-users] ray_trace issue!

[Lasse Riis Østergaard]

Hi

Any ray_trace experts here?

I am using ray_trace to render images of surface cross sections on  top 
of volume cross sections. I have been following the steps in David's 
tutorial (Example 14). This works very fine if the z-axis in world and 
voxel space are parallel. If this is not the case their seem to be an 
issue with the texture mapping as the gray levels are not interpolated 
correct!

Here is what I do:

1. make_slice volume.mnc slice.obj z w 5 2 2
2. plane_polygon_intersect surface.obj lines.obj z 5
3.  ray_trace -output image.rgb -nolight -line_width 1 lines.obj -gray 0 
300 volume.mnc 0 1 slice.obj -size 1024 1024 -bg white -crop -top -sup 3

ray_trace maps the grey levels of a slice along the z-axis in voxel 
space - not in world space!

By inspection I have found that the rendered slice exactly corresponds 
to z=78 (voxel space) wich cuts through z-coordinates 0.9-6.8 in world 
space.

Am I doing anything wrong?

cheers
Lasse