garageCube

Last weekend we had to map an complex object with two projectors ([1]). We used lines to easily animate the surfaces and live switch between the different patterns.
We had to mount the projectors very close in front of the object and because of the mounting possibilities and then pan and tilt both projectors. We tried to correct the warp with lens shift but it wasn't possible to correctly align both projectors to get one big surface.


[1] Setup with two Projectors

So we tried to use the madmapper output transformation to fix the image. But we discovered that it isn't possible to perspectively transform the output image of a projector. Why isn't this possible? This would help us in this situation then it wasn't possible to use one perspectively transformed surface because we wanted to use multiple line surfaces. We ended up in adding every line twice for each projector.

It would be great if it would be possible to either combine multiple surfaces to one big surface which is perspectively transformable or if it would be possible to perspectively transform the projector output.


[2] Setup with two Projectors

Have you already thought about this?

Here is the result of this mapping if you are interested: https://vimeo.com/159980602

You cannot Perspective transform a projector directly because it would involve one more rendering pass, which is bad for performances.
What you can do, is group all your surface in one group, then select the group and perspective transform it by moving the corner handles using ALT click.