MayaToLiggghts

My scripts for converting a (fairly specific) maya scene to input files for LIGGGHTS

These Mel scripts can be called from the Maya Command line, or better yet from a custom button on the shelf that calls "plfExport_Liggghts;"

In Maya, your scene should:

• Have z=up (for gravity)
• Be scaled to correctly (and maya scene left in cm scale)
• Motion will be calculated as though 240 frames = 1 second, regardless of maya frame rate setting.
• Have a tray called SIMINS1 (particles will be inserted into this tray)
  • Generally produced via creating a cube and deleting the face on top.
  • Keep this as small as possible to reduce particle numbers, but large enough to avoid edge effects
• Have a box around the entire simulation domain called "SIMBOX1" - this must include full extents of any moving object.
• Moving object(s)

Select all moving objects, then run "plfExport_Liggghts;" or "plfExport_Liggghts_deformable;"

You will see moving objects jittering through the full animation sequence.

TO-DO:

• For some reason coefficient of restitution ($cr) is not longer recognised by liggghts - need to hardcode for now. <-- I think this is because I already have a variable 'c' and it's using that?
• double check if I want sjkr or sjkr2 for material properties (I had issues with sjkr in previous versions of liggghts and moved to sjkr2 which is 'stickier'

**IF YOU USE THESE SCRIPTS, PLEASE CITE THE FOLLOWING PAPERS (which were instrumental in the development of these scripts):

• Falkingham, P.L. and Gatesy, S.M., 2014. The birth of a dinosaur footprint: subsurface 3D motion reconstruction and discrete element simulation reveal track ontogeny. Proceedings of the National Academy of Sciences, 111(51), pp.18279-18284.

• Falkingham, P.L., Turner, M.L. and Gatesy, S.M., 2020. Constructing and testing hypotheses of dinosaur foot motions from fossil tracks using digitization and simulation. Palaeontology, 63(6), pp.865-880.

• Hatala, K.G., Gatesy, S.M. and Falkingham, P.L., 2021. Integration of biplanar X-ray, three-dimensional animation and particle simulation reveals details of human ‘track ontogeny’. Interface focus, 11(5), p.20200075.