If you have an actual pixel based map (it doesn't matter what kind or how big) applied to your object when you unwrap it, you can turn on pixel snap in the UVW Editor, the button in the lowest right corner (you might need to change it from grid to pixel). Then in the upper right change the drop down so it displays your…
the UV shells need to be moved in from the left edge, they need more padding between the pieces, and you might need to increase the size of your light map. If this is all that is going onto this lightmap you should use as much of the space as possible, giving scale preference to pieces where you need the most shadow…
The tutorial didnt really help me in figuring out how to lock my verts to a per pixel basis :( or i just didnt notice how. This problem though produces some blurred edges where 2 pixels are trying to change, Whereas is a RIDICUlously crisp black line around the edges. as if its a vector in the texture.…
You can use overlapping UV's but you want your light map channel (normally the 2nd UV slot) to be uniquely unwrapped. If you don't have a second UV channel created I think it copies your first, which might be the problem you're running into? You can create a second channel on your own or have UDK auto unwrap a 2nd channel…