We tend to view most astronomical objects as flat images (with the exception of the planets and some asteroids & comets).
As a contrast to this there is a feature in the May-June 2015 issue of Popular Astronomy (the bi-monthly magazine of the SPA) on the 3D structure of Cassiopeia A the supernova remnant . I refer you to the article for an explanation however the 3D animation is available on this link: https://www.cfa.harvard.edu/~dmilisav/Homepage_of_Dan_Milisavljevic_%28SAO%29/Cassiopeia_A.html .
It is very interesting to see how the atomic material is distributed and where the high velocity material indicated the centre of the ‘explosion’ was.
Enjoy.
John Murrell
Astronomer Without Portfolio
Website www.JohnMurrell.org.uk