Rotoscoping complex objects (trees, leaves, nets…)

[Anonymous]

We’re working on a short film this year and there will be a lot of shots where CG characters will move behind trees and leaves. I have Mokey, but I can’t imagine that would mask out things like these too well.

In LOTR:TT, Smeagol at the end moves behind a lot of trees and branches, but how did they do this? Did they rotoscope the trees n things automatically or manually frame-by-frame?

Please help

[malu05_vb]

Well i think that most of the work on LOTR was made with a lillte blue plate in background. And then used some background replacement with a mattepaint or the background without trees etc.

So my advise would be, never do a that kind of shot without some contrast background!

Rotoscoping trees and etc will take a Man life, and is a damn waste of time!

[Anonymous]

Hm, I see your point. I’ll be sure to take a blue screen of some kind out when we do our forest-shooting.

But what goes on if the CG character moves behind something moving, like a person (with hair, oih) or leaves moving in the wind? Is this sort of thing even possible?

[TurboWidget]

This is just a thought ‘cos I’m a reseller not a digital artist. 😳
But if you’re taking a blue screen with you, you could try placing it between your foreground trees and background forest to give you two seperate “layers” (Call them layer A – foreground, layer C – background forest) You could them “insert” your CG character between the two (layer B)
It would still be a comping nightmare though.
Otherwise, why not CG a tree foreground and use that as layer A and blend the two together.
As usual, a totally rubbish idea from someone who still marvels at realtime page curls !

TW

[rego]

Well i did a shot just like this for 35mm, it took me a good 2 weeks, the particular shot needed a space ship lifting off in a forest with the camera behind the actor and lot of huge fans blowing the trees,leaves and branches all over to give the effect of the thrust. what was done here was blue light(night effect) was used behind the trees to shoot. I then used mainly the luma keyer in combustion to get a good matte. also some amount of roto. But it turned out good. also used some branches from a single frame and animated it to move alng with the rest.

[Anonymous]

Hm, sounds straight forward enough. I use Combustion too.

Here’s the scene. There will be children running through a forest as part of an action scene. They’re being chased by CG mechs, zombies and combine soldiers (yes, it’s a half-life 2 short film) and naturally things are going to be going behind trees constantly.

Seeing as the trees will go by rather quickley, do you think the best thing to do would be to just manually rotoscope the trees infront of the CG?

[rego]

Using a roto for the trees and leaves seems to solve ur issue i guess as the leaves wont be moving too much as there wont be simulated wind. and also they will be out of focus so u can use ur digital camera 2048+pixels and shoot a snapshot of some leaves urself and track them to the sene. So this way u will also not need to shoot the scene behind too many trees.This will reduce a lot of roto work. 😆

[Author]

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