What setting must be adjusted in the Time Manager to control Unity's physics calculations?

The Fixed Timestep setting in the Time Manager is essential for controlling Unity's physics calculations because it determines how frequently the physics engine updates the simulation. When working with physics, it is crucial to maintain a consistent update rate, which this setting provides. By setting a fixed timestep, you ensure that the physics calculations occur at regular intervals, which prevents issues such as inconsistencies in physics behavior or simulation stability that can arise if the physics update rate varies based on frame rate.

The Fixed Timestep allows for accurate and reliable physics simulation and is particularly important in scenarios such as character movement, collision detection, and interactions with physically simulated objects. This control mechanism helps achieve smoother gameplay and a more predictable physics environment.

Other options, such as Maximum Delta Time, Render Timestep, and Frame Rate, do not specifically focus on the regularity of the physics simulation. While they play roles in controlling the overall timing and rendering of the game, they do not directly impact how often physics calculations are performed, making them less suitable for this task.