I’m trying to make some basic modular pipes in Blender for import into UE4. I’m learning as I go, and trying to figure out good workflows during the process.
The pipes I’ve made are similar to the ones pictured below, in which the end caps with all the bolts etc are repeated a lot, one at each end for each type of pipe (straight, 90 degree corner, etc). https://thumbs.dreamstime.com/z/pipe-line-3d-14165542.jpg
On the third attempt at these pipes, I discovered group instances in blender as a way to help me more quickly make changes to these end cap pieces and iterate quicker as a result. (made them thinner, changed bolt style, etc)
So for each pipe type, I have one pipe object + 2 group instances of the end cap. The problem I’m now having is that UE4 throws a warning about overlapping light-maps when I import the model as an FBX. Now I presume this is because I only UV unwrapped the original object, and every instance just gets assumed to be in the same position with the same UV coordinates. Obviously this is not ideal.
My question is: is there a good way to have group instances have separate UV coordinates, or if not, is there a better way to handle duplication of often-used components in my models in a way that I can edit one and have those changes apply to all copies, in a way that’s lightmap friendly?
Thanks a lot. 
Context: First time poster. I’m very new to Blender/UE4 (let’s say, a week in), and teaching myself environment art for games (UE4 for now) as a hobby project. Pipes seemed like as good a place as any to start This is the first thing I’ve been unable to find a good answer for on google/youtube.