What is my mistake in creating the uv map of the lantern? I am trying to make a uv lantern for substance painter use, but I keep running into problems. 

this is uv map of this lantern
After separating the seams, I encounter gaps in the SP, it looks like a hard joint, but without separating into seams, it does not work out to make the correct UV map.

uv without manually specified seams (I used the  smart uv project function) I would be very grateful if someone could tell me what to do. maybe someone can suggest good guides for creating uv? I certainly found a few videos on YouTube, but they are all very superficial and almost useless.
First , I see some Overlapped UV islands (may I wrong because of image size).
Second , you should use a checker map to check your UV


then in Substance painter for some materials and texture coordinate you should change Projection on UV or Tri-Planer