Getting real close now....
It seems to me, without having tried it, that the directional masks might be generated more easily from the height map with 4 applications (n,s,e,w) of photoshop's standard "render lighting" filter.
Feel free to Fred Picker Stamp me ...
This is all a very clever idea with great results. Cheers! :)
I've actually come up with a much better way than the curves I was playing with.
I illuminate (emboss) three copies of the heightfield at 0, 120 and 240 degrees.
These get combines as RGB layers into a new image.
That RGB image gets converted into a HSV image and the H layer is grabbed out. This layer represents the direction (without magnitude) of the heightfield as a value from 0 to 255. I then posterize that layer into the number of faces desired, and select each colour sequentially, using that as a mask for rotated copies of the pattern.
It takes a while to run, especially for large images, but I like the results.
And it lets you (if desired) use up to 16 faces when generating the result:
I think I worked out the last couple of bugs on the weekend, so I will post it up, hopefully tomorrow.
Hi Rob, as a test would you mind running your script against this city which I am in the process of drawing? I'd be interested to see the results. If you need the image manipulated in any way for better results just ask and I'll post it here.
All the purple areas?
perhaps not the big ones just the ones that are finished.
I'm not sure if the pattern scales works with the map scale...but here is a result running once with the light purple selected and once with the fark purple selected.
I made heightfields with simple shaped spherical gradients based on the selection shape.
I begin to see why my simpler n,s,e,w idea won't work: the roofing material needs more angles to match huts that are at odd angles.
OT: speaking of odd angles ... @ Ravells ... hey pal, that city is tweaking my head. It almost looks as if the TAN areas should be the buildings ... bcz the PURPLE area are the funkiest shapes for buildings that man or alien has ever seen. But then ... there's tan lines (hahah, I mean lines colored tan) that look like streets ... but are they like tunnels btwn bldgs? Please do explain!
But your true when looking on the "rendered" version of RobA the buildings look strange. But I think this is that the building aria has been used as "one" building for test purpose. Maybe run RobA's Tutorial/Script method using Mosaic Filter to make building patterns for cities would gave a better result as you got a more regular structured pattern of single houses.
But on the other side I don't know about the maps cultural background so the strange look of the buildings basic form may be intended to be.