My problem with your idea is that as you mention you can't see several scenes at the same time, and there are many cases were you'll need to be able to see several scenes at the same time. For instance if you need to align two objects on different scenes.. Say the outside wall of a mountain on Page1 and the tunnel that goes inside it on Page2; you'd need to see the wall to precisely cut the hole and model the tunnel inside it. I know you get an object to display on several layers, and that's really useful, but I just looked and I can't find a way to display an object on several scenes at the same time; it appears you can only instance objects through scenes.
You can link an object to more than one scene by selecting it and doing CTRL+L.
After that it's linked to both scenes, and effectively shown in more than one scene. While any change in one scene will make it change in the other as well.
You'll need to be careful to unlink it from one of them, as a theoretical pyprp export would make a copy of the object for each scene.
So in the above example that means you'd first need to model your mountain and the tunnel in a single scene, and only when you are 100% done with the modelling you would move your objects to separate scenes..
(right now I haven't even found how to move an object to a different scene, only found how to duplicate it to a different scene and then to erase the original quite cumbersome).
I think a script could be made to move objects.
But if for some reason you need to update the entrance of the tunnel you'd need again to have both objects in the same scene... (That happened more than once in the past with Ahra, and that's certainly not a trouble I want to go through again if I can avoid it.)
linking the object to the other scene would allow for changes to be made to the object in both scenes, and after you're done you could delete the link in one of the scenes.
As I just said you can instance an object through scenes, which would be a work-around, but then what happens during the export? Do we get two duplicate objects? How would we assign it to one PRP rather than the other?..
Yes, it would be duplicated for each prp if it stays linked to both. By removing one link (removing it from one scene) you would set it to one prp...
Finally, right now we essentially export only geometry, but in the future, what about GUIs or animations? In Cyan's Ages those are always exported to separate PRPs, I'm not sure why but there must be a reason. Then how would that work? GUIs could easily be put to separate scenes but animations? And again with GUI we might need to put them in relation with objects in other scenes..
I heard that cyan uses a separate .max file for each prp.
And I think that once we implement custom animations, they probably won't be done in the same blender file as the scene, but will require a different export that exports that animation specifically to a separate prp. At the very least, it would have to be done in a different scene anyway, to avoid the animation distorting the other stuff.
But, to be honest, my guess would I think that there will probably be a separate program for making animations.
All in all I agree this would be a nice way to simplify page assignation, and to avoid wrong assignations, but right now the fact that you can't display several scenes at the same time really seem to be a deal breaker to me. However If we can solve this problem then that system would really seem to me like the way to go.
It just came to me that it would be pretty easy to create a script that makes a temporary scene with all objects in other scenes linked to it (and rig it so that it wouldn't be exported). It would be a snapshot moment though, as adding new objects to other scenes wouldn't be reflected in it until the script was run again.
You can then get rid of that scene by just removing it.
Would that be a sufficient solution?
One day I ran through the cleft for the fiftieth time, and found that uru held no peace for me anymore.