Wednesday, 26 May 2010

Compositing Live Action & Green Screen

So now the fun part! Filming & Compositing!!!

I had to change my idea a bit for the Motion Design students to help me out ... which, in the end, never happened as they would not get back to me at all! ... but I won't get into that.

Instead of the Advert being made entirely of Live Action footage I added Green Screen elements so that the world would change to be CG to fit better with the Boy's imagination.

It's been very challenging to time the CG characters' animation to move with the Boy after keying out the Green Screen. The same with the camera. This was even more of a challenge as the camera movements had to match exactly with the live action footage taken in the Green Screen studio, otherwise the CG looked totally out of place and did not fit in or look good at all.

Here's an example of one of the shots, from Green Screen to Animation. This was probably the hardest shot to do, but I am very happy with how it turned out. All it needs now is a bit of masking tweaks, rendering and colour correction.

Green Screen Edit:

Green Screen Edit from Aled Matthews on Vimeo.

Keyed out with Animation and Camera movement:

Final Alley Test from Aled Matthews on Vimeo.

Compositing CG into the Live Action background plates was more of a frustrating experience than compositing from Green Screen. Any slight movement in the camera which hadn't tracked properly would mess up the CG characters' movement, resulting in it wobbling or sliding which didn't help with trying to convey the character being in the world with the Live Action Boy character. As I hadn't had experience using the software Boujou for tracking before, I couldn't manage to fix the problem from there, so instead I had to manually (and painfully) animate the sliding characters on almost every frame to have it stay in the right place. Luckily I think I managed to pull it off, at least as best I could. I still notice a little bit of sliding, but hopefully no one else will!

This shot isn't the one which had the sliding problem, but this is an example of the Boujou tracking work I've been working on.

Live Action Footage:

Boujou Live Action Plate from Aled Matthews on Vimeo.

I was playing around with lighting and HDRI, and here's a test Render of the Elephant character in with the Live Action plate. The metal texture isn't there on the wheels for this render, and the Ambient Occlusion and Floor Shadows hasn't been added so he doesn't look perfect in with the real world right now, so once it's added it should look a lot nicer; but this is just a sneak preview of how the final film will look:

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