Hello Siming,
Maybe it is also possible to create a python 3 environment within Anaconda 2, but I doubt it. I'll double check tomorrow.
If you do install Anaconda 3, run then "conda install -c pytorch -c conda-forge -c anaconda -c aramislab deformetrica"
This "Python 3" requirement will be made clearer in our documentation, thank you for your comment ! :)
Best,
Alex