You can have several objects of different types in the same view. Lets superimpose a T1 MRI and the white matter meshes.
Load:
data_for_anatomist/subject01/subject01.nii
data_for_anatomist/subject01/subject01_Rwhite.mesh
data_for_anatomist/subject01/subject01_Lwhite.mesh
Open a 3D window by clicking on .
Drag and drop the 3 objects into the 3D window.
You can see the meshes but the T1 MRI is "hidden":
To view it, use the middle button of your mouse to rotate the objects of this window, and now: