Originally Posted by
pyrandon
Now open Photoshop, then File->Open the .bmp file you just saved from the City Map Generator.
Next isolate the map elements. While there are many ways to do this (the most versatile way being in saved Chanels) let's stay simple and direct: choose Select->Color Range, click on the background color, play with the fuzziness to be as exact as possible, then hit "ok." Then, with the “ants marching,” delete the background.
Repeat this Select->Color Range process with the buildings, the river, etc.--although instead of deleting, copy-paste each element into its own, individual layer.
• You'll notice I did not cut & paste the walls or towers: I found in tests it was easier to simply add them manually, later, if I choose to use them at all (for Koppollex I will not be adding walls or towers at all)
When I'm done creating layers for each element, I rename the imported image's layer "Original bmp file," then hide it by poking out the eye. I could, in fact, delete this layer altogether, but I'm a "layer pack rat" and so I save it just in case.
Now I have the exact same image as was imported, except with no background. So below the lowest layer I create a new layer ("background"), then use the paint bucket to fill a new layer with a solid green. [I've pasted a screenshot image, below.]
NOTE: If you decide not to use the Roleplaying City Map Generator, you should basically start with this step: create a "background" layer and fill it, then draw on your roads, buildings, etc., each in its own layer.