Importing 3D objects to animate within live action

Question

Regarding motion tracking, I'd like to import a 3D model of a robot and interact it with live action characters in a scene. Nothing too complicated - it hovers around but, it needs to be in 3D space for realism. What I've read of tracking, I can put an object in a scene and lock it down through camera movement and such. I would imagine the rotobrush tool will come in handy for this process. I just haven't wrapped my brain around how to animate this robot in a scene where the camera may be moving. Any suggestions?

Answer 1

3d tracking a scene is never "nothing too complicated".
The most important step is having a good script.
Other steps following that will include planning, storyboarding, shooting the scene (with enough tracking markers - or trackable elements - in the right places in the shot), shooting a clean plate (also, take the chance to grab some ambient room noise for your audio editing later), and shooting an HDRI - note: this is not an all-inclusive list.
That was all just pre-production and production.
Steps in post would include tracking the shot, modeling the 3d elements, texturing the 3d elements, lighting the 3d elements, animating the 3d elements, rendering the 3d elements and their various passes (object buffers, ambient occlusion, shadows, lights, motion vectors, depth pass, etc.), compositing your 3d elements into the scene (which will involve color correction and may or may not involve keying, rotoscoping, and other techniques - you'll figure this out during the planning stages), rendering out your composite in a proper intermediate codec, bringing your final shot into your editing program, adding sound design, color grading, and producing a finished file in the correct delivery codec. Again, there is more to it than this, but these are some of the basic steps.