Live Action with CG- Interaction

hey guys
I’m working on a short film and need some help with one of the effects. I need one of my actors to ride a dinosaur. There’s a few ideas i’ve thought of.
1- green screen the actor and motion track him onto the dinosaur (would look terrible)
2- make a 3D model that resemble my actor, and then put it on the dinosaur.

what do you guys think i should do? Does anyone know how they did Eragon?
Thanks

(btw, if this thread is in the wrong section, could a mod please move it. Thanks)

Dunno 'bout Eragon, but in Jurassic Park they substituted in a digital double, at the point where a man is snapped up by the T Rex. This was a wide shot at night so you couldn’t pick it.
Typically any King Kong movie is shot with large green-screened fingers holding the actress in peril. These are keyed over with the model Kong and the moves are matched to the live plate.

You could of course reverse the match as you say (place your keyed person as a texture on a plane, parented to the dino) but the ballistics of a person on a Dino (or other large beast) wouldn’t match correctly. i doubt that you could really talk an actor into being hurled around 10-15 feet through the air! But good luck if you can.

If it were me, I would construct the scene to occur in the dark with most shots in wide (worked for Spielberg!). Use insert or close up shots from a low angle looking up at the actor, this will hide the lack dino beneath. you could even render a riders point of view shot from on top of the dino, thereby eliminating the need of a rider in shot alltogether.

VFX are about tricking the audience, good luck.

thanks
there’s a shot i know of for sure that i want to get, which is the actor riding up over the hill on the back of a dinosaur. This will be the first time in the movie that you’ll see the actor riding it
i’ll do a little more research, and if any more questions arise (which they will) ill post them here
if anyone else has any input/advice on what to do that’d be great
thanks

alright
I think what im going to do is make the rider be a 3D model, and then for close ups just do a low angle of the real actor.
Any advice on how i can get the 3D model to look as close to my actor as possible and also make it look real instead of just a model
thanks

Use simple close fitting clothes and map real photos of actor to your mesh.

what do you mean by close fitting clothes?

Often the physics of the cloth sim wont match real world clothes, and if you model creases into clothing then it doesn’t bend or deform properly, so I was suggesting t-shirt & jeans (for example) and avoiding knee length coat or flowing dress. Same issue applies to hair.

Just advice, that’s all, I’m sure you will find what’s the best use of your time in the project anyway. As effects work is mostly problem solving, if you eliminate the problems at the start then there is less work.

gotcha
yeah, i don’t think there will be any loose clothing. Probably going to be futuristic military type padding/armor. I haven’t finished costumes yet, so not sure what everything is going to be like yet.
Thanks for the advice