Unity physics calculation on different platform

Unity Engine
1

Hi
I develop a 2D physic game. this game like a simulation and user has no effect on it.
In this game there are a number of entities. each entity has a script for apply force and torque in FixedUpdate method under non-random conditions. also manage collisions.

Run game with same init values on windows and android, but the final results are not the equal.

For example:
after N frame:
In windows log, position of A (game object) is 7.651319,7.52330__**2**__
In android log, position of A (game object) is 7.651319,7.52330__**3**__

difference is 0.000001, this is very small, but after N frame is bigger and bigger, until the final result is completely changed.

I use only FixedUpdate.

Is this problem really exist?
tnx.

2

The physics aren’t deterministic. If you want that, you’ll need to create your own physics engine.

–Eric

3

But if run game in several times, in each platform all log result exactly equal. if not deterministic, must each time different result.

4

You are getting different results, as stated in your first message. You also get different results on the same platform, though not necessarily with your particular test.

–Eric