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View Full Version : Duplicating camera moves


th3ta
04-15-2005, 11:26 PM
Does anyone know of a good way to recreate the same camera move, so that you can film multiple passes for compositing later on? I think it's all computerized equipment/rigs they use in hollywood, but does anyone have any ideas for the independent filmmaker? Thanks.

vrljc
04-16-2005, 08:46 PM
I am guessing that you are wanting to take your camera movements from your live action shot and get them into the computer? You need to do what is called camera tracking. There are a variety of camera tracking packages out there. I prefer Realviz's Matchmover, but others enjoy Boujou or PFTrack. There are some others out there but I cant recall them specifically. Take a look @ these links:

http://www.realviz.com/products/mpro/index.php
http://www.2d3.com/jsp/index.jsp
http://www.thepixelfarm.co.uk/

Take a good look @ PFHoe from the Pixel Farm. It is an inexpensive tracker that will give you a taste.

I hope camera tracking is what you are refering to in your post....

-jon

Aruna
04-16-2005, 09:10 PM
I'm assuming you mean motion control rigs.. There is no cheap and easy way to do this for the independent filmmaker that I'm aware of. What are you trying to accomplish?

th3ta
04-17-2005, 04:58 AM
Actually it's not camera tracking I was talking about, but thanks anyway Jon. I was talking about motion control rigs. I don't really have a specific effect I'm trying to do right now, but I'm planning on creating some effects in my spare time in the near future and just was wondering what kind of options were out there for when the time comes.

I guess an example would be if we had someone walking down a city street and something happened to him where half his body melted or he dissapeared or something. We could shoot 2 versions, both having the same camera move. One, as a clean plate, w/o the actor. The 2nd one with the actor. Then just animate the effect on the 2nd version, revealing the clean plate underneath it. But now that i think about it, effects like this happen all the time in commercials/tv shows/ films. Does that mean that everyone who does this effect uses expensive motion control rigs? or is there some other way of doing this that Im missing?

Thanks guys.

AlexK
04-17-2005, 08:51 AM
Well you could of course shot a blue/greenscreen shot of your actor. If you don't have the equipment try to find a hill or something and shot him in front of the best natural bluescreen there is: the sky.

sly
04-18-2005, 10:55 AM
You don't absolutly need a motion control rig to do those type of shots. With a well desgin camera move, you could always just reconstruct your clean plate manually in a compositing app by tracking patches (like you do when you remove markers).

Motion control is cleaner, faster and allow you more complex move though.

Sly

th3ta
04-18-2005, 04:15 PM
Yeah, the problem with using a greenscreen is that in the studio, you'de have to match the camera move that you used outside on the city street, so that everything matched up.

Thats a good idea sly. But how would you track over the actor or part you dont want, when he is constantly moving acrosss the frame and the background behind will be constantly changing?

AlexK
04-18-2005, 04:38 PM
How about you give a better description of the shot you have in mind? What kind of environment are we talking? What kind of camera move? Pan, zoom, dolly? Rotations? Free/hand camera movement?
I know you have no specific plans, but you surely have something in mind, right? Knowing this would definitely help in creating a working solution for you.

EDIT:
For automatic removal of objects you could use Icarus or the commercial version PFtrack. It has a cool function to automatically remove stuff from the background. It isn't completely flawless, but works great in many cases.

Oxide
04-18-2005, 06:55 PM
MoKey (http://www.mokey.com/products/mokey/) Might also do what you want.

Dutchman
04-18-2005, 09:30 PM
Well, that software is nice... ;) But what we're talking about here, is recreating a cam-move ;) (not the needed software), isn't it?! ;) :)

Your question is damn very nice and interesting! ;) I've been thinking of it veeery often, and have some ways to solve is ((almost) without any costs ;) );


Do it in a thinked way. For example if you want to have a pan, you can put your cam on a distance, and let not move it. Then in your post you can fírst do the FX stuff, and later put in the pan. Or if you want (comes down to the same ;) ), first do the pan-animation copy that animation (X and Y-pos) to the other footage (cleanplate for instance).
You could also just take the footage wíth pan, and later make some photographs to make a cleanplate (a still).
Because the stuff above here is just 2D (because the move is just 2D) it's easy to solve the stuff... But when you get to real rotations and dolly-stuff, you could better build a simple rig. First of all, you could try to 'build' some measurement stuff (think of the 'seisograph'-earthquake measurestuff), to measure sertain angels for instance. Then you can later recreate that movements frame-by-frameby doing the move in stop motion! Just by every time replacing the rig in the way it was done while shooting the footage!
I think this last way could be quite interesting for the 'hobbiest' like me... Just while typing this, I came up with that stop-motion-idea, but it seams to be quite well working..?!? Woeeee... I wan't to test that...!!! :bounce: :bounce:
Good luck with your stuff & I hope you'll be able to use the stuff roled-out-of-my-mind ;) ,
Gijs

XanderFX
04-18-2005, 11:28 PM
What is your budget for building this?

We built one of these at work for duplicating camera passes for an animation using physical models for the set. It has saved me so much time in compositing, because I can shoot a beauty pass, a greenscreen pass, Interior lights, exterior lights, and multiple exposures for the same shot, as well as lighting (Ping Pong Ball on a stick) and matchmove passes. I can key out the greenscreen pass and composite in the cg elements in a matter of minutes and matchmoving is super simple.

But cost wise it still cost over $2500 for the parts

th3ta
04-19-2005, 01:53 AM
I don't really have any ideas yet for my project, but one example I can think of in which they used a motion control rig was in X-men 2. When nightcrawler raided the White House. In that sequence there was panning, tilting, I think some of it even had a handheld look to it, from what I can remember.

So in that shot, they had a very dynamic camera move, with multiple actors in the shot. They shot a few different passes to seperate all the elements out. So they could just animate nightcrawler dissapearing to reveal the background or other actors behind him.

I think if you used greenscreen for something like that you would still run into the same problem of having to match your 2 camera's movements so the elements all matched.

That software looks pretty good, I might have to play around with that stuff.


Xander, sounds pretty interesting, can you tell me some more about the rig? I don't really want to spend that much on parts, since this is gonna be just for fun. But if i can get away with may 50-100 bucks would be great.

Thanks guys.

sly
04-19-2005, 07:05 AM
Yeah, the problem with using a greenscreen is that in the studio, you'de have to match the camera move that you used outside on the city street, so that everything matched up.

Thats a good idea sly. But how would you track over the actor or part you dont want, when he is constantly moving acrosss the frame and the background behind will be constantly changing?



Roto and 2D trackers. It's boring to do, but if you plan your shot before shooting it, it can works really well.

Another technique i've used sometimes is to track your move in 3d, reconstruct the part of the set that you want to clean in 3d, render and blend. You'd still need to roto out the actor and you need quite a precise tracking .

But usually, if you can't use motion control, you're better just to lock your camera.


Sly

Dutchman
04-19-2005, 03:56 PM
We built one of these at work for duplicating camera passes for an animation using physical models for the set.
Whoohoo....! Can you post some pictures of it!?!? :bounce: :bounce: I'm quite very interested how you did it....! Was it computer-controlled or so? Or just with some 'clever tricks' (some like I mentioned before?! ;) )?

Please more info! I'd lóve to be able to do stuff like you told (shoot allot of different passes and just combine them in post :) )

:bounce::buttrock:

Dutchman
04-25-2005, 10:59 AM
Whoo... lets *kick* this thread up :twisted:

Where have all interested people gone?!?! :shrug: I'm still quite interested in some pix of such an 'self built motion controlled rig'!

Anyone more? :rolleyes:

andy_maxman
04-25-2005, 11:59 AM
but one example I can think of in which they used a motion control rig was in X-men 2. When nightcrawler raided the White House. In that sequence there was panning, tilting, I think some of it even had a handheld look to it, from what I can remember.


a handheld camera move is the key, cos moves like panning, tilting are not gonna be as interesting.....
i would love to toy around with such ideas myself.....

Aruna, how about tipping us with an idea to have fun with this kind of concept....


edit - though not as clean.....mokey's demo (http://www.mokey.com/demos/mokey/) looks fairly interesting.... (esp. the dog one)

XanderFX
04-25-2005, 05:35 PM
Whoohoo....! Can you post some pictures of it!?!? :bounce: :bounce: I'm quite very interested how you did it....! Was it computer-controlled or so? Or just with some 'clever tricks' (some like I mentioned before?! ;) )?

Please more info! I'd lóve to be able to do stuff like you told (shoot allot of different passes and just combine them in post :) )

:bounce::buttrock:

Yes it is computer controlled.

I'll post some images this week?

Cheers!
:beer:

Dutchman
04-26-2005, 04:08 PM
I'll post some images this week?
Whooo, I can't wait till 'this week' :twisted: :twisted: :bounce:

Dutchman
06-09-2005, 05:20 PM
Whooo, I can't wait till 'this week' :twisted: :twisted: :bounce:
And I still can't wait... :twisted:

By the way: I 'imagined' another way to get a cleanplate: just make sure the cam makes (almost) excactly the same move (so the best on a dolly, and for instance driving along a line that you drawn on the floor), but the timing may be completely different.
Later you can retime/time-remap and mesh-warp to get the cleanplate (by comparing to the action-plate > lay them in 2 layers and set the opacity of the upper to 50%).
In that way I think you can get quite a good cleanplate, in a relatieve cool & simple way...! :rolleyes:

Is that method I just explained used in the 'prof-industry'? :)

Gangstashers
06-09-2005, 06:15 PM
Whaha je wilt echt die pictures of niet ^^

bartrobinson
06-09-2005, 11:20 PM
I thought Dutchman's idea of stop motion was interesting. Shot would lack any real motion blur though. Someone mentioned Mokey, which I believe is kind of a software solution for getting clean plates or mattes. I also seem to rememeber the folks from 2D3 showing off some research they were doing with the same type of thing. I suppose all automatic software like that stumbles on the real interesting shots though and it's an expensive solution. For handheld shots, I've heard of the DP just replicating the shot as close as possible, a digital camera with some high res stills for backup.... and some roto / matchmove artists track patches back over the subject. I think that was done on the latest Headless Horseman flick. I suppose clip would need to be pretty quick to hide that kinda trick though.

Dutchman
06-12-2005, 02:35 PM
Bart, good to hear you thinked my idea of using stop-motion was interesting... And about that generating cleanplates with software: it could work well, but then it's not anymore a challenge! :twisted: In my eyes it's better & more eductive to do it with the things you have or you can fairly easely create :)

In an upcoming project I need to generate some cleanplates, and I'm thinking of using a dolly and some markings on the floor, to be able to make the same move twice (with - as I said before - maybe a different timing).

I'll tell about my experiences afterwards :) & Please tell me what your experiences are with cleanplates and so... :)

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