Hi there,
I selected a bunch of poly group on my model, did a inset region. I noticed that since the edge loops are not even, the result looks quite sharp.
It got worse when I unfreeze my subdivision, as you see the mesh is now broken. After turn the polyfill off, I realize that the topology is really bad.
I tried to slide the edges, but the result is not good.
So how would I make the edge even so the mesh won’t break after subdivision?
Many thanks for all your help! 
Hi @Opheliah
You can use the Point> Slide function in ZModeler to slide the points in the problem area into a more relaxed position on the low poly mesh.
However, the “Freeze Subdivision Level” process may be complicating your efforts here, because it projects high resolution detail back onto the mesh, and it may be projecting detail onto that location where it is interacting poorly with your topology once it has been subdivided. When projecting detail, quad topology as close to square-shaped as possible produces the best results. Those long rectangular polygons you have created may not respond well to projection, and are likely to create a bit of a visible crease on a high poly mesh.
Unless your high res mesh contains details that aren’t apparent from the picture, the re-projection doesn’t appear to be contributing much here. You might consider abandoning the previous higher subdivision levels, and simply subdivide your low poly geometry back up from the low poly topology, which should avoid a lot of these problems. Once your low poly modeling is done, you can use ZRemesher to remesh it into a form more suitable for sculpting or painting.
If you must re-project the subdivision levels onto the low poly mesh, I would advise removing those long, thin rectangular polygons–the yellow group at the very least.
Good Luck! 