video : https://i.gyazo.com/2f4c338cdd91d52195a31399bdaa0fdd.mp4
when the rotation and position is lock it’s good as it’s set free it starts shaking and vibrating how do i stop this ?
Cube property
Have you tried the option “Enable Adaptive Force” in Project Settings > Physics? It’s an option explicitly intended to improve stability in stacked objects.
checking that option dint help. (at least it’s not visible difference ).
i solved it it was the problem with the mas i have to set the mass according to the area/size of the mesh then it got much more stable but it’s still moving (Video) i am okay with it will it done fall down. 
Making the physics material to be 0 on the bounce property should help too iirc.
I had a game where i needed stacking too, i ended up leaving them kinametic untill something enter the proximity of the structure and releasing all of it together(if you free them one by one you can end up with floating bits) with a trigger.
@Edy i though the adaptive force compromises some “integrity”/determinism/precision (don’t exactly know how to call it) to handle a massive amount of objects, never tried it though.
Yep, it shouldn’t be used with vehicles as contacts with other bodies may not cause the expected effects (i.e. extra weight because using other bodies as cargo). I guess that’s the point of the option after all, somewhat “faking” the forces at the contact points for increased stability.
