PoissonRecon generated surfaces are sometimes wrong when using -must-link constraints about visfd

[jewettaij]

Workaround (continued...)

When filter_mrc fails to infer the direction of each surface fragment automatically, the user can instead specify the surface fragment orientations manually. To do that, they can supply an extra number after the x,y,z coordinates on each line, which is "1" or "-1" (indicating the this surface fragment is pointing in the same or opposite direction relative to the previous surface fragment in the list, respectively). In the following example, the "-1" indicates that the two surfaces are constrained to point in opposite directions:

(141 83 62)
(123 133 64) -1

For a detailed explanation, see the documentation for the -must-link argument.