Unity Game Optimization - Third Edition

Maximum Allowed Timestep

It is important to note that if a lot of time has passed since the last fixed update (for example, the game froze momentarily), then fixed updates will continue to be calculated within the same fixed update loop until the physics engine has caught up with the current time. For example, if the previous frame took 100 ms to render (for example, a sudden CPU spike caused the main thread to block for a long time), then the physics engine will need to be updated five times. The FixedUpdate() method will, therefore, be called five times before Update() can be called again due to the default fixed update timestep of 20 ms. Of course, if there is a lot of physics activity to process during these five fixed updates, such that ...