UV unwrapping with precision?

(I might just put “please pardon if this has been asked before” and “I’ve done the search thing here and in google” in my sig line, but here goes…)

Let’s say you have a series of lines that look like a paper clip in the xy plane. Extrude it in the z. Now you have curved “wall” segments and straight “wall” segments. Now you want to UV map a brick texture onto this curved “wall”. Problem: how to get a good UV mapping to get the brick image to curve around the curves and run along the straight segments without getting stretched, while maintaining even brick coursing. (The actual model I’m working on is more complex than a paper clip, this is just to get the concept down.)

My method has been to make seams where the curves and straight segments meet, and do a combination of cylindrical and square UV mappings, then, attempt to pin the vertices in the map together to get reasonably straight, consistent lines. But its really tedious, and I wondered if there’s a better way.

BTW, do I need to specify an radius for the cylindrical mapping that matches the radius of the “wall” curve?

Have you tried unwrapping with lscm yet? Its pretty good and did well in the little scenario i set up. Should do the job.

You’ll need to learn set seams for lcsm to work well though, check the blender docs for more.

For this kind of UV mapping I find my UV Map Tool best suited. Just assign your corner UV coords for this tool and it will do the rest.

ForTe, Jellywalker: thanks, I had tried the LCSM and it gave me some very bizarre results. The tuts I’ve read all use a head or a simple block. The issue is the precision: sure, if you’re doing a head or some such, you can afford to guesstimate with the textures when you Gimp or whatever, but with something that has coursing (stacking) and discreet units to it, you’d see stretching with randomly curved walls. Of course, I can try to manipulate the UV map to try to solve this, but my real question is: “hey, this seems like it would be a fairly common problem when modeling buildings, is there a quicker way to do this, or am I missing something with the method?”

Ashsid: I’ll try your script. Thanks!

Update:
You LCSM folks were right: it does the trick, as soon as I remembered to set the seams in the window openings too. %| I didn’t realize I was getting both sides of the wall when I tried to select the outside faces; obviously a very bizarre result ensues. Thanks!