I want to make an animation title screen kinda like what sega has been doing with sonic 1-4 in 3d, but I need to know how to make it so only the character's upper body shows. Does anyone know a technique similar to this?

A good example is here:


Around about 0:09+ it shows the characters upper body appearing in the ring without their lower half showing. I need to know how to do this.

In any soft you'll use to mount it just use simple mask to hide lower body parts.

As Baalnazzar wrote, you can do it in after effects or any other compositing software with masks.
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Andyba, 3d artist
skills: 3d modeling, texturing, rendering, 3d character animation, compositing
3d software experience: 3ds max, Maya, Softimage XSI, Deep Paint 3d, Body Paint 3D, Wings 3D, Z Brush
2d software experience: Adobe Photoshop, Adobe After effects, Macromedia Flash, Freehand

Not trying to be mean, but if you have to ask about something so simple, are you sure you want to make what you are asking about? Masking/transparencies is one of the first things you learn in creating digital compositions. Think photoshop layers...

But, learn maya/3ds/modo/lightwave/blender or your choice of 3d animation program, premiere pro, and after effects.