Generating grasps off-object or for only half the object with non-cubes [possible solution]

[Au3f]

When using the TwoFingerGraspGenerator to generate face-grasps from the top for objects that are not cubes there is an odd behavior:

• Objects that are taller than wide will result in grasps generated next to the object (mid air)
• Objects that are wider than tall will only have grasps for a part of their dimensions (exactly their height)

It looks like the dimensions or number of grasps along the faces got mixed up somehow.

After further investigation, i think i found the Problem: In two_finger_grasp_generator.cpp at line 410,422,508 and 520 num_grasps_along_a should be passed to addEdgeGraspsHelper instead of num_grasps_along_b.

These modifications fixed the issue for me.
Hopefully someone of you can verify the Solution and maybe add this as a fix.