Screen replacement in After effects with some roto

Screen replacement in After effects with some roto

by Ben Lewis

on Apr 16, 2015 at 10:38:40 pm

Firstly thanks for let me asks this question. I genuinely find this site so useful.

I've been vfx supervising on a shoot and i will also being post where i am needed to replace a few screens on iPads , iphines, and big screen oh and mocked up touch screen table surface.

This final one with cause me most problems I fear as I have multiple hand movements over screen of table. We did place green paper under the glass on the table to see if it would help pull a key. So I have my footage which was shot on canon c300 and I need to replace various screens but the shots in which others interact with screen I may have to roto around moving fingers etc.

Think minority report on a Microsoft surface thingy

Any advice or tips would be ace! Thanks

Re: Screen replacement in After effects with some roto

by Dave LaRonde

on Apr 17, 2015 at 3:24:01 am

I am sorry, but we have no idea. We know nothing of the shots you have, and we have only sketchy knowledge of the green screen shots you DO have. I'm afraid that without more details, we aren't much help.

Dave LaRonde
Promotion Producer
KGAN (CBS) & KFXA (Fox) Cedar Rapids, IA

Re: Screen replacement in After effects with some roto

by Ben Lewis

on Apr 17, 2015 at 10:16:41 am

Hi Dave,

Sorry I didn't include more info but I hope this should be some help…

This is a quick turn around pitch film and I'll need to comp in some shots of 'concept UI" onto a coffee table we added a green section to. ( Photo Attached ).

I fear that in a addition to keying, I will also need to rota around the actors arm as he swipes. I am using AE CC and cutting the piece in Premiere.

Any help would be greatly appreciated.

Kind Regards

Ben Lewis

Re: Screen replacement in After effects with some roto

by Dave LaRonde

on Apr 17, 2015 at 4:18:32 pm
Last Edited By Dave LaRonde on Apr 17, 2015 at 4:20:13 pm

I'll assume this is a locked-down shot; no camera movement.

Mask out the table surface. Duplicate the layer. Temporarily turn off the upper layer and set the mask on the lower layer to subtract mode to make a hole for the interface, which goes on the bottom-most layer -- use Corner Pin to put it in the proper position. Turn on the upper-most layer and use one of the blend modes to put the reflections on top of the display; you'll probably have to futz with colors and levels to make the reflections look realistic.

On top of all these layers, roto around the actor's arm on a duplicate layer.

Dave LaRonde
Promotion Producer
KGAN (CBS) & KFXA (Fox) Cedar Rapids, IA

Re: Screen replacement in After effects with some roto

by Ben Lewis

on Apr 17, 2015 at 5:56:48 pm

Yes it's a locked off shot. Thanks so much for you advice in this matter.

Kind Regards

Ben Lewis

Re: Screen replacement in After effects with some roto

by Darby Edelen

on Apr 20, 2015 at 3:00:25 am

I'd key the green to get close and then roto as needed to fill in holes.

As for the reflections I'd recommend using a despill method (I still like Channel Mixer) to remove the green from the table and then Screen your interface footage in on top.

The keyed/roto'd layer would go above that.

Darby Edelen