Equidistant fisheye model

[qume]

Using Equidistant fisheye model (equidistant_r3) always seems to fail at this line: https://github.com/alicevision/AliceVision/blob/bc7c981c31a0f119da37f1f6ff1865f09bbaf679/src/aliceVision/sfm/pipeline/sequential/ReconstructionEngine_sequentialSfM.cpp#L1205

Has this been run successfully? And if so is there a trick to getting past this error?

@servantftechnicolor we would very much like to use this, as the standard fisheye models based on pinhole model don't seem to be adequate, and this looks like a needed improvement for wide fisheyes/