A lot of 3D programs will allow you to import video as a background, then you can superimpose your 3D model on top and output the finished video back to a disk file. Hollywood, though, probably render all the 3D objects as seperate layers and then use a special compositing program to combine them for the finished frame.

I haven't used Adobe After Effects, but that seems to be one common compositing/effects program that's used for video, and I believe it includes features such as camera tracking so it can analyse the video and figure out how the camera moved (if it wasn't stationary on a tripod) in order to make your 3D model appear to be in the correct place.

i have after effects, mad confusing progra,. still trying to learn it. other then that do any of you know any programs that lets you import 3D?

and are there any tutorials i can use on the net. this is the only kind of topic that baffles me and is very interesting. plus, to me, its the hardest skill about low budget film making to find on the net. its really hard to find tutorials, programs, etc.

can anyone help?

Fantastic Firsts, Sloppy Seconds, Tickilish Thirds, Filthy Fourths, Fouling Fifths, Slippity Slappy Sixths, and the Seventh person scrapes her off the mattrass

For simple 3D stuff in the past I've just exported it from the 3D program as .TGA files with a white or green background, then imported it to Premiere as a numbered image sequence and used the transparency settings to layer it on top of video footage. But that only works well if the camera is stationary and there's nothing in front of the 3D objects. Any decent 3D program should allow you to export as a numbered .TGA sequence (i.e. frame0000.tga, frame0001.tga, frame0002.tga, etc).

do you know any good programs? 3D studio max? lightwave? etc

Fantastic Firsts, Sloppy Seconds, Tickilish Thirds, Filthy Fourths, Fouling Fifths, Slippity Slappy Sixths, and the Seventh person scrapes her off the mattrass

I use Lightwave myself, but a lot of people like 3D Studio Max. I'm still waiting for my Lightwave 8 upgrade CD to arrive in the post so I don't know what new features that has, but Lightwave 7 was the best compromise between cost and features when I bought it a year or two back. The other programs had better features in some areas, but tended to require extra plug-ins to do things that Lightwave could do natively.

i just dloaded Lightwave 7, Discreet Combustion 3, and 3D Studio Max 6, now im totally confused. I dont know what to do. LOL

Anyone know of any tutorials????

haha

Fantastic Firsts, Sloppy Seconds, Tickilish Thirds, Filthy Fourths, Fouling Fifths, Slippity Slappy Sixths, and the Seventh person scrapes her off the mattrass

i just dloaded Lightwave 7, Discreet Combustion 3, and 3D Studio Max 6, now im totally confused. I dont know what to do. LOL

Anyone know of any tutorials????

haha

Fantastic Firsts, Sloppy Seconds, Tickilish Thirds, Filthy Fourths, Fouling Fifths, Slippity Slappy Sixths, and the Seventh person scrapes her off the mattrass

There are PLENTY of books you can buy from amazon.com. Also, try Maya, good program.

Make your 3D elements in Lightwave or 3DMax, whichever you're most comfortable with (Maya is pretty much the industry standard). Next you have to render out frames from your 3D package - be sure you've got an alpha channel, and that the width and height matches your footage.

In Combustion, import your video footage, and the rendered sequence. You should be able to feed both into a composite node. In Shake (which I prefer), you can do an A over B.

You then render out the composite node.

This is simplified, and I hope it helps.