Some ideas:
1) Several shots : instead of one . As Rodrigo commented and Brad Larson tried to get around his method, the problem with the user accepting only one drawing for input is that you do not have enough information to create a triangulation and form a point cloud in 3D. With 4 shots taken from a slightly different angle, you can already restore parts of the subject. Comparison of point clouds will facilitate the operation of any ML algorithm, neural networks (NN), vector machine support (SVM), or others. A common standard for creating point clouds is ASTM E2807, which uses the e57 file format.
.
2) . , , , . , " ", , , , . , . CAD-, , "", .
1) , .
3) . . , . . ( " , []?" ). .