Arrange UV maps of multiple objects without joining them I am trying to arrange multiple pieces of an outfit to fit onto the same texture. Some of these outfit pieces are already unwrapped before being imported to Blender, and so cannot be re-unwrapped as they have no seams. Some pieces have mesh caches on them, so they cannot be joined into other objects without destroying their vertex indices, and thus breaking their caches. Other objects are being unwrapped for the first time in Blender.

In order to properly arrange and optimize my UV islands, I need to be able to view all of these object's UV maps at the same time. I could export all their UV maps as images, arrange them in photoshop, then re-import that and align their UV maps to the image, but this is imprecise and inefficient.

My googling has turned up that the usual method is to join objects together, but I can't do that. Is there any other way I can work on multiple object's UV maps in blender at the same time?
There is a tool that will allow you to visualize the islands from other objects that are still separate.  To use it, select all the objects and enter Edit mode for the primary selection that you are currently working with and check View->Draw Other Objects.  Now all UV Islands for the secondary selections should be visible with a faint outline in the UV Image Editor.



If you would like seams for objects that are already unwrapped: Enter edit mode for the object and select everything; there is a tool available UVs->Seams From Islands that will add seams to all the islands.