I tried to establish the scale of the main theatre map. I have added this blue 5-foot grid for clarity.

The key thing about the theatre is that it is symetrical. This means that we only need to make 50% of it, and then mirror our images for the other half. Also, many of the stories have lots of open-air space so again this helps to make it easier.

For the basic ground floor layout, I see us needing to create a map of 5,000 pixels long and 1,600 pixels wide, as per the red area on the image below. This should be doable in one map or perhaps in two half-maps. Lets call it two 2,500x1,600 pix maps.

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After this base is done, we can then create the basement - two more maps of the same size that we again can mirror.

Then the upper floors: three of these in total I think. This makes six more maps. Thus we need 10 maps in total. Since this is a good bit more than anticipated, I propose we just deal with the three most important seating floors first, and then later on if we want to, we can add in the roof storage and basment.

So, to conclude:

1. two 5000x1600px maps ground floor theatre & main stage.
2. two 5000x1600px maps upper seating level & second backstage level
3. two 5000x1600px maps box seating & third backstage level

Did I get those the right way around? Or are boxes supposed to be lower than the upper seating?