How to emulate a curved screen

Hi, I'm trying to emulate a venue setup.

The screen is 21m x 3.6 m. And sligthly bended (curved), so more like a cylindrical view.

If I take a cube, and bend it, then project on this, I can line up 4 projectors, but they will look straight and not bended/curved with the screen.

So how can I bend/curve/displace the output from a projector ?

Projectors user rectangular DLPs or LCOSs. The only reason they projector is able to warp the image on the screen is by warping the input image. You can do a similar warp in Fusion. Start with a gridwarp to get a feel for it, then use Texture to do the final warping once you figure out the distortion needed.

Thanks, sounds like a very reasonable explanation.

I'll try.

Alternatively, you could use an ImagePlane with the footage mapped onto it,
bend it,
and then use Camera3D to render it.

When projecting through a camera, and rendering through the same camera,
the image will naturally look exactly the same as the projected one...

If you can visit the venue, project a flat grid on the screen and take a perpendicular photograph if it. Bring the distorted image into Fusion and reverse the distrotion unti the grid is flat and straight. Then you will know how much to distort your own images for output. (If you have multiple projectors, you'll have to do this for each projector.)

If you can't visit the venue, discover the actual dimensions of the screen, including the specifications of the curve. Then build a model of the screen to spec, and project the flat grid on it in fusion and render from a perpendicular camera view. You can then do the same calibration as described above to determine how much to distort your image in post.

I've heard from friends who do a lot of curved and domed venue work that they do everything flat and then distort for the dome after final output. They'll do some test wedges in the beginning to make sure the pipeline works, but then they just distort everything as the absolute last step.

Alternatively, you could use an ImagePlane with the footage mapped onto it,
bend it,
and then use Camera3D to render it.

When projecting through a camera, and rendering through the same camera,
the image will naturally look exactly the same as the projected one...

I can not use it as a mapping, because I have to emulate the usage of the picture from the projector as light for people on stage.
The projectors is going to be used as light and video at the same time...

have a look at this video from youtube (this is a projection and lighting... not my show, but a good example of how we gonna use it)