Usually Autopo has been working reasonably well for me. But now I have typical-looking human character model where the Autopo process just doesn't produce anything. When i get to the end of the wizard I get a retopo object listed, but it doesn't have any geometry in it. I tried various options in the autopo settings, and also tried converting the model into voxel mode, into surface mode, various different density levels, using the strokes and density paint or not, etc. Usually these all give me different results in the output topology, but I'm just getting nothing. Is this normal, and just the result of having some settings wrong?