[Joshua Steadman]

Walter–
So a possible workflow for our curved screen (which is 15×8′ but only 8.5 inches deep at it’s most concave point):

1. Adjust keystone correction in hardware and get projected image to fill entire screen.

2. Put up a 1280×720 grid and make note of bowing (outward at bottom, inward at top)

3. Adjust/Warp the production to account for bowing

This keeps all keystone correction in hardware, and we just account for the bowing in the production.

Thanks for all input;
Joshua Steadman
steadyfilm@mac.com
Raleigh, NC USA

[Joshua Steadman]

First, I’d work in your regular 1280×720 comp for production. As the last step, I’d precomp that into a separate 1280×720 comp for warping and output.

Check, will do on that. Should make the process easier.

Working with a digital camera as you are may be introducing additional optical distortion from the camera’s lens. Get in the space with an AE machine, drop a grid in your production comp, then switch to the warped output comp. Apply your Bezier warp, send that full-screen on a second output to the projector, and tweak live.

Yes, forgot to mention I ended up doing this as well. I tweaked live, but wasn’t happy with what I was supposed to be tweaking to. Even with the grid in place, I felt like I was guessing. Is there a way to have corrected points I’m mapping the grid to in place?

[Joshua Steadman]

David-
Thanks for the input. Both the producer and myself realize we’re only correcting for a person standing directly in front of the wall/projection, but we’re still going down this road. Goal here is to make it look right from dead on, and let the other perspectives be slightly warped.

As far as a workflow, I’ve done a live preview in AfterEffects to a projector with a grid superimposed over a test image, but I’m unable to warp satisfactorily. When I am warping, am I supposed to be warping the image to please the eye, or putting the grid points to other specific points? In the case of the latter, what are my other points? It almost seems like I need to somehow have a second grid which is completely true (not warped) that is superimposed over the projected (warped) grid. That seems impossible.

If the answer here is WatchOut, we both accept that. But I’d like to know if we’re almost there, but missing a small step that would enable our current workflow.

Thanks,
Joshua Steadman
steadyfilm@mac.com
Raleigh, NC USA