Projection-mapping interaction between 3D and 2D elements

[Hilary Tsai]

Oops, it looks I didn’t attach my images correctly that time, so I’ll send them here.

Auditorium:

Panel set-up:

[Steve Bentley]

I’d worry less about the C4d Mapping. In the end you are putting 2d content onto a 3D surface. So you can certainly have a a floating 3D cube casting a shadow on the surface and it will look like it’s floating out from that surface but its the warper in MM that’s looking after correcting the projected image that would be distorted by the shapes on stage. Dragging a particle emitter left to right, MM will look after it undulating across the various surfaces. You can setup edges in your “2D” c4d comp or in AE that the particles can react to without going through the pain of building a true 3D representation of whats on stage.
But you can also build simple versions of the planes in C4d so that you can have particles bounce around. These don’t need to be perfect and can be done by eye. With the exception of the POV spot and edges lining up, 3D mapping is very forgiving. Shadows, contact points, lighting all reenforce the illusion so as long as you get close with these it usually sells. You really only need to be super accurate when you are mapping an image of the building you are mapping onto.

There are a number of plug ins that allow you to import OBJ files into AE and you can use those to help composition or (in some plug ins) texture them directy with sub comps (Video Copilot’s element 3D is brilliant at this).
You can also position planes in 3D space in AE and then sub comp them leaving all attributes in the outer comp so you have flat surface to compose on in the inner comp but can be angled and 3D in the outer. And a mask on this solid can be used to trim the shape to match your on stage geometry.
For positioning you can export nulls from c4d that come in as nulls to AE, as well as lights and cameras. If you animate these that data comes in as well. But be warned there is no rotation data you can play with in AE on lights or nulls. But you can bring in a camera and it comes in with everything and is fully rotateable – we use these all the time, not as cameras, but as nulls we can hook geometry to in AE and then play around just as if we’re in C4D. Just make sure to turn the cameras you are using as nulls off (the eyeball icon).

We’re probably starting to annoy the CC gods with length so here’s an email you can send to if you want to send designs etc and I can point you in the (hopefully) right directions. This can be brain melting stuff (should I predisort this? or is the distotion happeing in MM? or should I make it flat?) steveb@sharktankdigital.com

[Steve Bentley]

So a couple of thoughts. Pictures can be deceiving but that looks like a pretty close audience to a pretty big screen. That means that your POV spot is going to be very very small – like two seats. On the plus side the screen geometetry looks simple and clean, which will help expand that spot.
I suppose I’m a POV snob because that’s the only place the illusion truly works, but given how people rave about projection mapping even when they have seen it upside down and the perspective is inside out perhaps I’m the only one who cares.

[Hilary Tsai]

Thank you for these further suggestions! I agree about the “CC gods”. This exchange has given me lots to work from.. Will certainly import C4D camera and null groups for better control in AE. Very glad to know the precision is not of huge importance unless mapping architecture; I’d antagonized over that part so much that I think it overshadowed everything.

Steve, if there is a way to rate you as “best answer” or boost you in this forum somehow, please let me know. You have been very generous with your time and guidance and I truly appreciate it.

P.S. about the auditorium POV, those chairs are just always there by default. For the actual event, I will be able to customize the seating and move them further away.

Thanks!

[Steve Bentley]

One other thought. You are going to be wasting a huge amount of light and resolution because your projector can’t do that format and encompass all screens in one shot. So there will be tons of pixels above and below the screen. This would be better with three projectors, one for each flat. The larger you have to blow up the image the dimmer that image becomes and for that size of screen, 4k isn’t a lot.

[John Ord]

Sorry to bump and jump this thread. But i was wondering if you had contact details Steve, and if i may pick your brain and potential work.