HowTo:Unwrap in Blender
I'll assume you've done other UV-unwrapping tutorials by now, but are unsatisfied. If you haven't, should do so before proceeding.
The problem with LSCM is it puts all the islands in a row, totally random order, at random angles... Is there a better way? Answer is Yes. The secret is to use LSCM as a post-optimizer, but to do the initial unwrapping using more comprehensible functions, such a Cylinder, Sphere and From Window. For this tutorial, I will use Dual Joe's WCU Hornet model, simply because I was just working on unwrapping it. I'm going to unwrap half of the inner surface of the Engine's compartment. I will use the From Window function to get the initial layout, while viewing the model from behind. If you've no idea what I'm talking about, you will on second read. Correctly parsing this tutorial may take two passes :)... The vertical wall, behind the engines, will be facing the camera, so it will be correctly unwrapped by the From Window function. The surrounding polygons however will need to be re-adjusted with LSCM. I'll assume you know how to go to "potato mode" and split the screen, and change the right screen into a UV-layout screen.
Here's a snapshot of the work in progress, we'll just unwrap one shape and add it to the layout:
Before we start, make sure you have Draw Faces and Draw Shadow Mesh selected
(they should be on by default, really... No, they aren't; I'm saying Blender's devs should have set these on by default...)
Okay, ready? So, first we want to select the surface. Make sure you're in face select mode. Right-click on any face, then hit Ctrl-L. The island on the UV-screen at right becomes selectable.
On the potato view screen, make sure you're in orthogonal, NOT in perspective view (Hit Numpad 5 if necessary), then hit the U key...
... and select From Window, as shown above. After you do, that section will unwrap exactly the way you see it on the left screen...
Don't worry about its being on top of other shapes in the UV-layout screen; we'll move it to a good spot, eventually. Now hit A, in the UV-layout screen, to select all the vertices:
And Pin all the vertices...
Vertices turn red when they are Pinned. Now in the 3D window go to Edit mode... (You can do this in Potato mode, if you prefer; I find Edit mode more versatile for selections)...
And select all the facets that aren't facing you flat in the initial unwrap; --in this case, the sides, top and bottom...
Press Tab to go back to potato mode. Note how only the sides, top and bottom are now selectable in the UV-layout.
Make sure all vertices are selected, in the UV window, and hit Alt-P to UN-Pin all:
Trust me! We should look like this now:
Now, in the potato window we select the entire group again. Either Ctrl-L or from the Select menu -> Linked Faces
Note that in the UV window, the faces that are facing you are pinned all around; the others aren't... Good!
Good! So, now we can do an LSCM; --by pressing E, or from the menu...
And then, BINGO!
Notice that the problem of the small size of the sides got fixed, now. That's what LSCM is good at. What it sucks at is initial placement. So, whatever facets are orthogonal, you're best off unwrapping From Window, and do the above to have LSCM fix the rest.
Next we want to select and Pin all vertices in this island, to make sure it doesn't change anymore.
And then you can rotate it (R), scale (S) it, Grab it...
You might ask, why not just select the faces facing you, pin them, Ctrl-L, E?
Answer: Because it doesn't work. Weird things happen. Vertices get split. Poltergeist...
AFAIK, the above is what works. Select all and Pin; Select non-flat-facing-facets, un-pin. Then E.
Uhmm... May look long, but it isn't. Much longer to explain than to do.