In Blender when you are in the UV/Image Editor window I am confused as to what the “pin” command does (p button). From what I read on a couple other sites it sounds like it should pin down the vertices you have selected. I don’t know exaclty what they mean by that, but I would guess that that means that it should be impossible for them to be moved or recalculated differently until you unpin them. But in my testing this is not the case. What exactly does the pinning do?
Having not got far doing any uvmaping myself yet i thought how you discribed pinning was right,so ive just fired up blender to have a play and uvmapped the default box.
I pinned 2 verts and then turned on lscm live transform.I found that i couldnt move any of the verts that where not pinned but if i grab a pinned vert it will move and it moves the unpinned verts around it and trys to keep the same shape of the surrounding unpinned verts as you move it but any unselected pinned verts do not move.
weither thats of any use to you or not is another matter but i tried %|
You can think of it as like putting pins through a piece of skin on a board, so you can stretch it around. The demo video here should give you an idea: http://mediawiki.blender.org/index.php/Release_Notes/Image
that video helped a lot. Thanks broken