surface test-mesh deformation only?

[super gnu]

i doubt it, but might there be a way for the surface test to react to *only* velocity coming from mesh deformation rather than object transforms?  

my lovely client wants particles flying off as the object changes shape, but not as it moves..  considering these two things happen simultaneously and at similar velocities,   i cant do it with timing controls, or thresholds.  only certain parts of the mesh deform and they dont want particles coming off the rest..

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On a related note, client has now asked that the thrown-off particles  are thrown off in a more spherical pattern, rather than rigidly following the surface normals of the object. 

im using "surface force" with "motion" set to 100%. 

i assumed adjusting "diverge" at the bottom would randomise the directions nicely, but it seems to do almost nothing to particle direction.

[SiriVFX]

for the first one: you could attach particles to the surface and than let these particles emit new ones with inherited motion.

[super gnu]

for the first one: you could attach particles to the surface and than let these particles emit new ones with inherited motion.

sounds promising, but i cant follow how that would help?   wouldnt the emitted particles behave the same as my current ones?

[tyFlow]

Hmm, no currently there's no way to test local deformations (besides setting it up in a script operator) that I can think of.

Also the surface force diverge option diverges existing velocities, not ones assigned by the same operator that step. I should probably change that in the future as it's not very intuitive. For now, to diverge, use a speed operator with both modes set to 'inherit', then set the diverge setting to your liking and timing to continuous.