Kevin, what kind of reasons did your TD give for not wanting to use multiple projectors? If it is the lack of resources, we might still be able to guide you in the direction you need to accomplish the task.
Do you know how many windows on the train cars? I assume that the director mentioned a single projected
image on the
cyc for
ease of use, but as mentioned before, sending images directly to the windows may be a more viable option, but since there are two train cars, a single
projector may not be the best solution.
Consider your
line of sight, how does the director imagine showing motion in the foreground to match that in the background. For instance, do we see the bottom portion of the train cars at all? Is there empty space between the cars or is there a masked portion? Does the action take place during the day, night, or both? During the day scenes, is there the plan to also use lighting on the
cyc or is the plan for the projection to provide for the entire lighting in the background as well? If the plan is to add light, you are going to be needing a
projector bright enough to compete with the additional light. If the plan is for the
projector to be providing all of the
cyc lighting, then your foreground lighting will need to be dim enough so that the projection depicting
daylight outside is bright enough to simulate that. Either way, you will need some bright projection.
I agree with using individual monitors per window, if possible. You might also consider a
screen at an angle, just outside the window that you project on, so that the
cyc is lit separately. You should be able to control the light so as not to affect the projection, but this would ideally need multiple projectors. If you cannot spread your
image large enough, simply mask some of the windows with
curtains or shades (but I'd also close some in the middle of the set to give some semblence of
continuity). Of course, with all the shades pulled,
gobo rotators could work as well.
<rant> Certainly the conveyor scenic method has worked for many years and is a viable alternative with its own challenges. However, in this case, that would be like telling someone that their actors should learn to project when the poster wanted information on how to use a wireless mic. </rant>