Still very much early days with this project. The scene will show the construction of the Erie Canal aqueduct over the Genesee River at Rochester in 1823. The foreground will be a construction zone. The open meadow in the background (behind the red mill) will become the village of Rochester. So, placement of vegetation and ground details will change quite a bit.
Here is what this view looks like today:
https://www.google.com/maps/@43.1546713,-77.6088796,3a,75y,287.58h,82.01t/data=!3m6!1e1!3m4!1stdg-TNxSttQlpP2y8gh12w!2e0!7i16384!8i8192?entry=ttu.
As you can see, the historical landscape had to be built from scratch. Here is the process I came up with:
Using a old survey, I painted a rough 32-bit elevation map in Photoshop. Key elevations only: riverbed, millraces, islands and ridges. Everything was based on a datum in the riverbed. So, if an elevation was 12 feet above the datum, that area was painted with an RGB value of 12.0. (Actually the values were normalized so they would be visible in PS.)
The elevation was imported into Terragen and a vector displacement map rendered. The VDM was imported into ZBrush, where rough transitions were smoothed and some details added: riverbanks, shelving in the riverbed, the rocky ridge on the opposite bank.
The edited surface was exported as a new VDM from ZBrush and placed in Terragen, where the final displacements and details were added.
It sounds like a lot of work, but it's much faster than using masks and simple shapes, which is how I would have done it before. And it's forgiving. Any problems can be easily fixed in ZBrush and a new VDM exported.
It's very accurate. The levels are right where I need them to be. This is important because all of the structures on either bank must be aligned properly with the river. The aqueduct model, which will extend from the near bank to the rocky ridge on the opposite side -- nearly 800 feet -- must fit perfectly.
I'll let you figure out how the water surface was modeled. There are some errors there that will be fixed as the scene gets finalized, so no need to point those out.
