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So.. I've decided to take on mission impossible.


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Hi.

 

So. An experienced 3D artist and myself have decided to make, a short, 'Dinosaur' film.

 

Some of the 3D Designers Work

 

It's probably going to be shot this summer on the XL1s. We have no solid storyline at the moment, but I imagine it will be heavily influenced by 'Dog Soldiers'. (We'll have some army costumes and some replica guns)

 

It will be joint directed, but I'm the DP. What I really need to know is, what tips and tricks can you post here as to shooting a film with live action and 3D elements? Getting the live elements to react with the t-rex e.t.c.

 

We both have a basic understanding of tracking markers, but if there's anything else you can add about them, please do. And as a DP I have a basic understanding of how to shoot these kinds of films, BUT, any tricks you know of could really come in handy.

 

Do you think it is realistic to start mixing 3D elements in with footage shot from an XL1s?

 

Thanks.

 

(We don't expect this film to come out amazing... but we're gonna give it a shot anyway)

Edited by Daniel Ashley-Smith
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Daniel first thing ditch the xl1, this is not just from the tracking perspective- which will be a nightmare, but more from the compositing perspective. do everything you can to get a real hd camera and use simple lighting so that it can be easily recreated. finally do not underestimate the need for a decent compositor. and test test test.

 

keith

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If you're doing a lot with effects, I strongly recommend looking into shooting on a camera that can do 4:2:2 at least. You're probably going with the XL-1s because someone has it and it's free or very cheap to you, but you'll probably be kicking yourself during post because the heavy compression and subsampling will make things more difficult than they need to be.

 

That said, take a lot of measurements on set, shoot a mirrored ball with bracketed exposures, and do lots of testing. You need to know what trackers can pick up on, so you'll know when and where to place markers, so do lots of testing beforehand if you can.

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five little things that are necessary, beyond motion tracking markers...

 

- build a physical stand-in for the material/surface of the dinosaur that's as big as you can get it, and shoot a seperate reference take of every vfx shot with it in place. seeing how the light interacts with something of the same color, luminance, specularity and texture will be an invaluable resource for when you're trying to get the dinosaur to "look right", especially if your compositor isn't super experienced. i know it's impractical to build a full size dinosaur prop, but a large blob would probably suffice. you might wanna try buying a large vinyl beanbag chair, solidifying/plumping it up with more styrofoam, and then applying the craftwork to get the surface to look like what you want the dinosaur to look like. then figure out some easy system to rig it up with c-stands for the various shots.

 

- shoot cast shadow plates, or even just reference. meaning, for every shot that the dinosaur appears in, find a way to shoot a pass that has the dinosaur's cast shadow in real cast shadow (the real cast shadow will undoubtedly exceed the area of the dinosaur's cast shadow). you can either use a large flag or design your lighting in a way that allows to turn off a single source to do so. this way, you can use the 3D render's cast shadow pass as a matte for the real cast shadow, rather than try and use the 3D rendered cast shadow to look right (which is very challenging). and generally speaking, you should just try and design your shots to omit the dinosaur's cast shadow, or minimize its size and complexity. especially if you're shooting amongst a lot of foilage.

 

- an old trick in vfx is to plan some shots to have foreground elements (when the 3D is in the midground), and then add them in the composite to help spatially integrate the 3D. an example would be to have a shot of the dinosaur in the midground, and have marked c-stands in the bottom of the screen in the foreground (or if you are confident enough in your 3D tracking, you won't need the foreground markers). in post, track the c-stands and replace them with tree branches that partially or momentarily obscure the dinosaur. if the trees are out of focus, you may be able to get away with CGI trees, but i'd recommend shooting those elements on red screen for better results (though this may not be feasible depending on your camera move's parallax).

 

- if there will be anything made to be out of focus in compositing, make certain that the compositor has a depth of filed simulator that properly emulates bokeh/circle of confusion. i see so many low-budget/amateur composites that are probably passable, except they completely ruin it because of use of gaussion or box blurs to fake depth of field.

 

- and also, your 3D person may already know this, but it is absolutely necessary to use multipass rendering if you want to enable your compositor to even come close to achieving photorealism/intergration to the footage.

 

best of luck.

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Ok thanks guys. Definatelly some good advice there, we would have just ran straight into these problems.

 

To be honest, I don't think we can afford to start renting good camera kit out, so for now, I think we'll just create a 3D/live action film, but a much more simpler one. We'll knock something up and post it here, mainly as a tester, since as neither of us have done anything like this before.

 

 

Cheers.

 

(Random note, happy b-day Keith, enjoy it man.)

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  • 4 weeks later...

Does anyone know what makes the best looking incendiary explosions? Unfortunately my 3D designer hasn't got much experience with modelling them so we're going to need to create a real one.

 

Petroleum based explosions are the best I can think of.

 

One shot I was *thinking* about doing is videoing a jet fighter screaming past over head at an air show, interpolating it onto the live action plates and then draw in a very basic 'missile' object (in Photoshop) flying down just before the explosion detonates.

 

Now that, would look good.

 

I know this film seems ridiculously out of my hands, but I'm thinking that by pushing myself to the extreme I'm going to learn more.

 

And I have a basic model of what the t-rex will look like.

(I know I said I was going to scrap the idea but by the time I told the 3D designer he'd already started working on it so..)

 

del.jpg

 

(Bare in mind that this IS, only a very basic version of what it will look like, I knocked up the composition in minutes and the image of the t-rex was extremely low-res)

 

EDIT:

 

Oh and, here are some very basic models of the 'helicopter' establishing shots we will use. (Since as we don't have a helicopter... they wouldn't let me borrow one)

 

scene1s.jpg

 

scene2.jpg

Edited by Daniel Ashley-Smith
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Ahh... those could DEFINATELLY come in handy, cheers guys.

 

I got another comp of the movie, the t-rex's are a bit small, but you get the idea:

 

rex.jpg

 

(The lighting was altered and the perpective of the shot was changed in Maya, and some basic shadows were included)

 

 

And I've got a small, basic video clip:

 

Video Clip

Edited by Daniel Ashley-Smith
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Quick question, does anyone know where to find the best price on renting a Panasonic SDX900 for the weekend?

 

And how much do you think it would cost to transfer about 4 hours worth onto my own external hard drives? (I don't want to go renting out editing suites, I just want the footage on my computer at home to edit when and how I please)

 

Thanks.

 

(I can't seem to find one anywhere... infact I can't find much atall, Sony Z1e's seems to be the main HDV camera being rented out, I'd of liked a JVC or the XLH1)

Edited by Daniel Ashley-Smith
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  • 3 weeks later...
Hi.

 

So. An experienced 3D artist and myself have decided to make, a short, 'Dinosaur' film.

 

Some of the 3D Designers Work

 

It's probably going to be shot this summer on the XL1s. We have no solid storyline at the moment, but I imagine it will be heavily influenced by 'Dog Soldiers'. (We'll have some army costumes and some replica guns)

 

It will be joint directed, but I'm the DP. What I really need to know is, what tips and tricks can you post here as to shooting a film with live action and 3D elements? Getting the live elements to react with the t-rex e.t.c.

 

We both have a basic understanding of tracking markers, but if there's anything else you can add about them, please do. And as a DP I have a basic understanding of how to shoot these kinds of films, BUT, any tricks you know of could really come in handy.

 

Do you think it is realistic to start mixing 3D elements in with footage shot from an XL1s?

 

Thanks.

 

(We don't expect this film to come out amazing... but we're gonna give it a shot anyway)

 

I'd suggest you try a test shot first - on the XL1. It's been a while since I used one of these, and I recall the image as being particularly soft. You are going to run into trouble tracking shots in 3D if theres too much motion blur, since the image is soft anyway - I'd suggest increasing the shutter speed to get a sharper image. It might not be the aesthetic you want (the whole overused saving private ryan knockoff thing) but it'll certainly make it easer to track...

 

On the 2nd test render shown here, there are alpha problems on the render (there's a slim edge around it) - looks like you are not premultiplying the alpha properly. Was this test done in photoshop? Also there's no contact shadow on the ground, and the creature itself doesn't appear to be lit in a way that matches the ambient light in the BG image. Have you tried using some kind of GI, or GI cheat?

 

Also you have to be really carefull of the black levels of your renders matching the darkest blacks in the surrounding image - a neat trick when comping is to add an adjustment layer in afterFX (if that's what you are using to do the film comps) and do a really extreme curves correction to contrast it up like crazy. It will exaggerate the DIFFERENCE in black levels between your render and the BG image, and make it easier to see where you are going wrong...

 

re-tracking markers - x's or +'s are better then circular markers (like ping pong balls), because they have more hard "points" that a (automated) tracker can pick up on

 

Also, any time you can do 2D tracks instead of 3D, you are gonna make life a hell of a lot easier on yourself...

 

best wishes,

 

Ruairí Robinson

www.ruairirobinson.com

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Yeh we're trying a few of those things you mentioned, I'm putting the shutter speed up to 1/120th, obviously shooting in progressive scan.

 

We shot some test shots last friday, and Rob the 3D designer is going to digitise them today hopefully and then start work on some compositions. So, we should know if this is going to work soon, hopefully.

 

We'll be using Boujou for the tracking, neither of us get along too well with after effects.

 

What I'm fearing the most is making clean rotoscopes of the trees. We made some nasty shots... it's going to take a while to mask things off (if they aren't too soft to mask off clean)

 

And the rendering time is about 5/8 minutes per frame, and that's on a fairly good pc.

 

Well... we'll see what happens. We've got tons of test footage to work with so I'll post back here with the status and results.

 

I also have a new still, the last one wasn't very good in comparison to this (Rob was a bit 'out of it' when he made it...)

 

Shot3Finished.jpg

 

And this is just Rob and I...

 

dan.jpg(Dan)

rob.jpg(Rob)

Edited by Daniel Ashley-Smith
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