Hi-

You can try loading the *.spec file in your command, as you had done before.

Open the SUMA object controller ("View" -> Object Controller), and hit the "All Objs." button in the ~top middle row. Just to the right of that, you can navigate to the control panel for your desired object (in your case, you have two objects-- the *.ply file, and the volume file) by hitting the up/down arrow keys, and seeing the name of the file change just to the right.

In the volume controller window, then go the the left side of the panel, about 1/3 of the way down to the "Volume Rendering Controls". Right now, probably the square next to the 'v' is dark-- if you click on it, then that will put you into rendering the volume as a volume. Above this section of the control panel is the 'Slice Controls'. You can turn *off* each slice (which you are currently seeing) by de-selecting the little boxes next to the 'v' for rendering each slice.

Note: If your volume is a whole brain or something, then your tracks might be occluded at this point.

--pt