In this tutorial I will show you how to import that data into your 3D program, create some virtual elements and render out all of the layers you will need for compositing everything together.
I am using 3dsMax for this tutorial, but it doesn't really matter which specific 3D program you use. You should use to one you're most comfortable with. The theory behind each step should apply to all comparable products like Maya or Cinema 4D.
Create a new project in 3dsMax and go to your render settings. Set the output width and height to match the footage you shot for the 3D integration effect. I shot the UFO scene in 1080p so I will go with 1920x1080. Often it is useful to work in half or quarter resolution until you are ready to export the final render simply to make the iterative workflow faster.
Set up the renderer you want to use. I am going with the Default Scanline Renderer for this tutorial.
If you have vRay - and know how to use it properly - I highly recommend it, but that could be a whole new tutorial in itself and I don't want to over-complicate things here.
Close your render settings.