The first image is a rendering of point-clouds detected on a ruin.
[Points To TINs]
There are overhang points included.
3DChain changed points into TINs. Generally the shape seems to be good, but the direction of TINs is not correct.
Divide the former shape into some parts as generally flat and perpendicular.
Flat parts can be processed with Points-to-TINS program for no overhang.
Perpendicular parts can be processed after coordinate exchange.
Assemble all the parts.