I create a really simple test scene in Maya 2014 SAP :
A cube, which I make an Active Rigid Body.
A plane, which I make a Passive Rigid Body.
A 2nd cube, which I make a Kinematic Rigid Body.
I put 2 keyframes on the 2nd cube so that it starts away from the active cube and then collides with it after a few frames (quite slowly so I don't have to touch substep settings).
So far things work fine, the 2nd cube impacts the first one and it reacts to that.
But then I want to enable the 'Initially Sleeping' attribute on the active cube, so it should not move at all until the 2nd cube collides with it. But now the collision has no effect, the cube just passes through it and it never becomes dynamic.
I tried the same setup in Maya 2013.5 and in that version the 'Initially Sleeping' has no effect at all, the object moves from the start of the timeline as if the option was disabled so it seems broken in that too, but in a different way.
I tried the same thing in C4D too (which also has a Bullet-based solver) and it works fine, but it’s kind of a pain having to export geo back and forth just to get this working (my real files will be more complex than this test file of course).
With some further experimentation I figured out that sleeping objects don’t get woken up by collisions with kinematic objects, only other active ones (they wake with either in C4D) . Bummer as I want to trigger the animation with keys to have it happen at a precise frame.
So..is this option broken in both versions? Any ideas appreciated. I tried Dynamica too instead of the supplied Bullet plugin but it doesn't seem to have a start/initially sleeping option at all.
2014 scene file attached to demonstrate.
Cheers,
Brian