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#1 bogdanovici barbu

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Posted 24 August 2017 - 12:33 PM

hi guys! 

I have a question about shooting a specific scene in wich a over-the-top fashionable lady will appear at a garden party, and after she catches the eyes of everyone participating, she gets attacked by a pigeon - she'll be wearing a big overdecorated hat that the bird is supposed to mistake for a nest(ha-ha). 

Now, the bird will be CG, this turned out to be the best option.

the whole scene will look as if it's shot by one of the invitees- via smartphone. 

 

This being my fist project involving CG, i'm pretty unsure of the elements that I need to address.

 

So I was thinking that after we get the clean shot, the hat will need to be shot independently on a blue screen, also some of the decorative elements of the hat will need to be shot independently so that they could be layered on top of the pigeon that lands on the hat. markers/trackers will need to be added.

I'm deffinately missing things I must be doing, so any inpunt on the matter will be of great help to me.

 

Thank you!

B.

 


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#2 aapo lettinen

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Posted 24 August 2017 - 01:22 PM

do you have a storyboard and stills of the scene and especially the hat available?

 

with composites the elements needed will depend a lot of which element is in front of /behind which element and how practical or unpractical it is to key or rotoscope and how much the perspective changes.

 

Without seeing photos I am highly sceptical that you would have any benefit of shooting the hat separately, the actress will probably move so much with it that you can't imitate its movement in the clean plate. And if the bird flies from behind the hat (the hat is first in front of the cgi element and then the cgi element goes in front of the hat plate) you will need either bluesceen the actress WITH the hat which would probably be very  unpractical OR rotoscope the corners of the hat which are in front of the bird at the start of the shot (I would recommend this approach) . 

 

Are you on fixed camera or can arrange a camera setup which has no parallax error when panning/tilting at the start of the shot (if the camera is not dollying in any direction) ? if so, you can shoot a clean plate of the background WITHOUT the actress or any extras/actors on the path of the flying bird. then the actress with the bird hat IF the corresponding hat corners can be rotoscoped easily if the bird is flying behind them. if the decorative elements can also be rotoscoped easily it may be easiest to just shoot those two elements and rotoscope the bird behind the decorations when it lands.

but that depends on a lot of variables and you may need to 3d track the hat's movement when the bird is on it to get the bird's perspective change to appear right. 

 

I recommend shooting on high quality camera+format and deteriorating it after the vfx is done to get the cellphone camera look.

 

What your vfx supervisor said about the scene? as said it depend on how the bird flies and how the hat moves and especially the hat elements colors compared to the background colors and each other (to determine if rotoscoping is practical or not or if blue/greenscreen is needed) . 

(for example if you have feathers etc. very difficult-to-rotoscope elements on the hat and almost similar color background, you may need to use chroma/greenscreen and rethink the vfx)


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#3 aapo lettinen

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Posted 24 August 2017 - 01:34 PM

of course if the hat does not move 3d when the pigeon lands you can do the separate elements shoot and imitate the pigeon landing with a keyable pole etc. which moves the hat decorations. but that necessitates that the perspective and hat position and angle would be exactly the same compared to the live action shot so it would be very difficult to shoot and may take hours. 

 

I would recommend doing the pigeon landing interaction at the same time when shooting the live action element, using a small thin pole or similar to move the hat elements when the pigeon lands, or some kind of remote controlled system. then you would not need to worry about getting exactly matching hat elements plate. you will need, of course, a clean plate of the background anyway to mask out the pole and correct the hat corners if they need rotoscoping.

but as said you may manage with only the live action shot and a background plate if the storyboard and hat allow it


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#4 dan kessler

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Posted 24 August 2017 - 01:49 PM

How and why would you shoot the hat separately?  I think I'd just opt for a CG hat along with the bird.


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#5 aapo lettinen

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Posted 24 August 2017 - 02:01 PM

Real hat would look better if on a budget. But it would help a lot if seeing a image what kind of hat it would be. Maybe if absolutely necessary one could make the top of the hat cgi, would look more real than full cgi and easier to track. Best would be if you could use real hat and just remove the decorations which cant be rotoscoped. And choose the decorations such a way that there is suitable details which can be used as tracking points
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#6 aapo lettinen

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Posted 24 August 2017 - 02:04 PM

Shooting the hat separately would probably need a motion control systems for both the hat and camera and motion capturing the live hat. But dont know for sure with the current info
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#7 dan kessler

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Posted 24 August 2017 - 02:26 PM

I agree just doing the top of the hat as CG would make tracking easier.

If that and the bird are CG, it's just head motion you have to track.

All the hat and bird interactions take care of themselves.


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#8 bogdanovici barbu

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Posted 25 August 2017 - 04:17 AM

hey, guys!

so this is a photo of the hat(minus decorative elements). it looked like this yesterday, in the mean time i demanded that the whole hat needs to be opaque.

252fQQa.jpg

 

working the ornaments/top of hat in CG isn't really an option because there-s no budget for this. Mind you, this is a really low budget shoot.


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#9 aapo lettinen

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Posted 28 August 2017 - 06:11 PM

hey, guys!

so this is a photo of the hat(minus decorative elements). it looked like this yesterday, in the mean time i demanded that the whole hat needs to be opaque.

252fQQa.jpg

 

working the ornaments/top of hat in CG isn't really an option because there-s no budget for this. Mind you, this is a really low budget shoot.

 

what kind of decorative elements you will add? those hat edges themselves are relatively easy to rotoscope as long as the background is not similar colour. 

it might, however, complicate things if the hat will be opaque (depending on how clearly you will see the background and bird through the hat surfaces) . if you can manage with a bird not showing through the hat when flying behind it, then it would be much much easier to do. (you can, of course, also play with opacity and masks in the compositing program to get the bird somewhat appear through the hat, without needing to key through it... that would do quite well when a fast fly-by)

 

I was asking about the decorative elements because for rotoscoping the edge shape and roughness and motion blur is extremely critical and for example simply adding some feathers to the hat for decorative purposes may make the rotoscoping 10x more difficult than it would otherwise be. depending on the background colour and texture and the tools available of course. 

But for fast flying object like the bird I would say the rotoscoping approach could be the most practical route, the bird's motion blur will mask most of the imperfections of the effect. Just be very careful to not do anything which makes the rotoscoping more challenging for you (like adding something hard-to-rotoscope elements to the edges of the hat or choosing hat edge colours which are very close to the background colour. or shooting with very shaky handheld camera which motion blurs all over the place so that you can see clean edge only every 20 frame or so) . 

 

You may need to add some decorative elements to the hat for tracking marker purposes, near the place where the bird is landing and two or more markers which show how the hat is turning around its z axis. it would be best if the actress does not turn the hat around z axis when the bird has landed, you would otherwise need to either 3d track the hat z rotation or try to imitate it manually in 3d program which would both be very challenging to do with that hat design


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#10 David Mullen ASC

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Posted 28 August 2017 - 07:10 PM

If the bird is CG and attacking the hat, then the hat should be CG then as well.

 

Or if you are just going to jerk a real hat around with monofilament, then you might as well leave it on the head of the actor in the scene and simplify your composite because having to track a real hat against a green screen on top of a head might be the hardest part of the shot, unless your actress' head had been fixed in a clamp (at which point, again, why not leave a real hat on her?)


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#11 aapo lettinen

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Posted 28 August 2017 - 07:48 PM

I would personally use a real trained bird rather than trying to do a realistic one with CG but if it really has to be cg then so be it, maybe it's a good exercise at least  :rolleyes:

for low budget the best option quality wise would be to jerk the real hat as per the birds movement I think, not trying to do any more elements CG than absolutely necessary... and trying to prevent the z axis rotation of the hat when the bird is on it so that the bird can be added with 2d or planar tracking and does not need to 3d track "match move" the hat rotation to get the bird a matching perspective change  :ph34r:


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