Reverse modeling design:
Template Entity-Measuring Point (Point Cloud)-Line (Curve)-Sheet (Surface)-New Entity (Modify)
I don't know what you do. If it is three-dimensional scanning (also called coordinate measurement), you should also pay attention to many things. The measured points should be divided into colors, layers, anchor points, etc. (all for the convenience of UG modeling).
The point cloud is imported into UG. In UG, a three-dimensional drawing (entity) can be made by fixing coordinates, fixing demoulding direction, making curves, making curved surfaces, stitching curved surfaces into entities and so on. This process is incomprehensible here.
There are many books about reverse modeling. You can buy it to study.
A book I read before: reverse modeling design-UG NX4 example detailed explanation (Chinese version) is ok, more suitable for beginners.