2D physics performance

Hi, everyone!
Recently I came across an interesting article in my local language about performance issues that are connected with the nature of Unity physics engine, and how to solve them. link to article(rus)
Three main unity physics laws that author claims are:
The violation of these laws could result in massive performance drops because the engine marks the collider-violator as improper and initiates the re-initiation of such and the recalculation of phisics.

1. Colliders should not move, rotate, scale or enabled/disabled.
Ordinary collider is should be a static object like a tree or so.

2. The movable object should always be a rigid body.
As a rigid body does not initiate the entire recalculation of physics, only local, but it should be moved with the help of rigid body methods.

3. If the object is a rigid body it should move only by rigid body methods.
Forget about direct control of object movement through transform component if it has a collider attached. transform is a 'killer of performance'.
Use rigid body methods instead:

1. AddForce, AddTorque (the engine calculates the movement and collision depending on the mass of the body)
2. Velocity and angularVelocity properties
3. MovePosition, MoveRotation.
(See the details in the documentation)

The author also gives an example of 20box colliders movement and results in profiler.
on the left transform.position / right rigidbody2d.MovePosition


So the purpose of my post is to make a discussion of this topic, because some of the facts above were not obvious for me, and these mistakes do make difference on low-CPU devices.

What do you think about that?
P.S. what do Lerp method etc use for movement? and iTween?

 

transform.Translate gives MUCH better performance than adding force. It seems more efficient to simply set a new Vector3 position.

 

I agree with you.
But the author of the article, said that for the purposes of his game it was more efficient to move the level in his game using MovePosition, MoveRotation.

He said that he had really bad performance on low-CPU devices with transform methods, but after swapping to MovePosition, MoveRotation he got a growth in 30 fps.
The only thing that bothers me is that low-level rigid body control methods does not bring a smoothness in movement as of the nature of it.

 

You're the author
Btw that game in your post seems SUPER cool! If it's yours, i recommend a little damping of the plane... give the camera some momentum.

 

hi bro, "that low-level rigid body control methods does not bring a smoothness in movement as of the nature of it." i also had met this probole ,i use move rotatioin , the robot head shake ...