How to create a UFO scene without breaking the bank

In this VFX article, we will show you how those big production houses make all those massive UFOs fly over cities. This is not a step-by-step tutorial, but rather an article that will show you the theory behind the practice. You still need to know the basics of your editing software, masking, and motion tracking in order to build your own invasion scenes though.

Note that the method described here is not the only way to achieve this.

If you know of other ways to create this effect, feel free to share your knowledge in our member forums.

First, the footage is shot. You will notice that UFO scenes like the ones in Independence Day, District 9, and the new V television series are short and choppy; changing from one angle the next in three seconds or less.

Next, the art department will create the 3D UFO in software like SoftImage, 3D Studio Max, or Maya. The UFO wireframe is textured and rotated to fit the angle of the shot perfectly. In our case, budget forced us to improvise and use a frying pan (or in this case, a flying pan) for our UFO.

When your UFO is ready, simply bring it into your editing software and overlay it with the background footage.

The city footage is duplicated and placed over the UFO. A mask is then used to outline all the objects that should be in “front” of the UFO. Everything not included in the mask would be “behind” the UFO if it were to move past it.

The UFO can now be positioned in the scene to ensure that all the masks are placed properly. If there is movement in the scene, for example the camera man driving or running, the masks will have to be moved and adapted with the buildings. This can be extremely time consuming, and is one of the reasons you will only see a few seconds before the scene cuts to another angle. A good cut would be to show one or two people getting out of a car and looking up towards the UFO. This would help sell the illusion.

Final touches can now be made to the UFO. In our example, we decided that a larger UFO would look more menacing.

Basic shadows against the buildings will round off the shot nicely. The shadows are also revealed through masks and can be animated to move with the space ship. A good “moving shadow” shot was in Independence Day when the space ship flew over the Obelisk in Washington.

Next time you watch one of these alien invasion movies, take a minute to dissect the scene. See how long they show the UFO before they cut away, how many times they jump around between the UFO and people’s reactions, etc. etc. and try to emulate it in your own project.

If you don’t have a high-end 3D program in which you could render a UFO, you would probably be relieved to know that Blender (Blender Foundation) is a free, open source, 3D studio for animation, modeling, rendering, and texturing offering a feature set comparable to commercial 3D animation suites. It includes features such as multi-resolution sculpting; retopology painting; 3D view texture painting; and other features. Blender is developed under the GPL and is available on all major platforms including Windows, OS X, Linux, BSD, Solaris and Irix. Download it here.

So go for it! Challenge yourself and build your own UFO invasion scene and then upload it to YouTube and then send us the link. The best ones will be highlighted here.