Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: 3D Morphable Face Models -- Past, Present and Future   In this paper, we provide a detailed survey of 3D Morphable Face Models over
the 20 years since they were first proposed. The challenges in building and
applying these models, namely capture, modeling, image formation, and image
analysis, are still active research topics, and we review the state-of-the-art
in each of these areas. We also look ahead, identifying unsolved challenges,
proposing directions for future research and highlighting the broad range of
current and future applications.

9
The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph
36
The categories of this paper are: cmp-lg
5
The categories of this paper are: gr-qc
30
The categories of this paper are: q-alg
31
The categories of this paper are: ao-sci
7
The categories of this paper are: hep-th
4
The categories of this paper are: cond-mat
11
The categories of this paper are: hep-lat
27
The categories of this paper are: comp-gas
26
The categories of this paper are: bayes-an
29
The categories of this paper are: funct-an
10
The categories of this paper are: q-bio
21
The categories of this paper are: adap-org
17
The categories of this paper are: q-fin
3
The categories of this paper are: physics