An example of how Physics Corrector adjusts an animation.

The main part of the AutoPhysics simulation.
This tool analyzes the animation you’ve created and suggests a physically accurate version of it.

Physics Corrector tries to make an animation physically accurate by adjusting the position of the Center of Mass and the character’s rotation on every frame. It also takes into account the friction coefficient and the collision surfaces for each of the Fulcrum Points.

Enabling Physics Corrector

As Physics Corrector provides the central part of AutoPhysics simulation, it is enabled by default.
However, you can enable (if it was disabled for some reason) or disable (if you don't need it in your simulation) manually:

1. Go to the AutoPhysics tab on the Physics settings panel.

2. Turn on (or turn off) the Physics Corrector option:

After this, you should see the effect on the simulation.

How it Works

Physics Corrector corrects the animation not only by moving the Center of Mass, but also by rotating the character.
Rotation is used for adjusting the character’s ballistic trajectory, as it isn’t possible to solve with translation alone.

When the character collides with the floor - or with other objects - the type of collision defines if the rotation should be changed or not.

Physics Corrector can work differently depending on the type of collision:
• For the ‘surface’ type of collision, the algorithm is only applied when the character collides with a collision object ( the ground or some physical object). There is a dedicated group of settings - Physics Corrector Surface - specifically for this type of collision.
• For the ‘pin’ type (when the character is suspended on some kind of climbing hold), the algorithm is applied constantly, to every frame where the character is attached to the pin. These collisions are influenced by a different group of parameters - Physics Corrector Pin - is used.

Settings

If you need more precise control over AutoPhysics simulation, there are several groups of parameters for this.

Main Settings

This is the main group of settings. It works for both kinds of collisions and defines how the algorithm adjusts the animation.
It can be found on the Physics Settings panel,  under the Physics corrector tab:

Frame Weight
Sets the weight for preserving translation and rotation on interpolation frames.

Key Frame Weight
Sets the weight for preserving translation and rotation on keyframes

Normal Ballistic Weight
Sets the weight for preserving the along normal position on frames before and after a ballistic interval.

Tangent Ballistic Weight
Sets the weight for preserving the position in the collision plane on frames before and after a ballistic interval.

First Last Position Weight
Sets the weight for preserving the first and the last frame of the animation.

First Last Velocity Weight
Sets the weight for preserving the velocity on the first and the last frames.

Force constraint weight
Sets how much the physical limit of Newton’s 2nd law influences the algorithm.

Torque constraint weight
Sets how much the physical limits of the momentum influence the algorithm.

Friction constrain weight
Sets how much the friction constraint influences the algorithm.

Geometrical constraint weight
Sets the influence of the limits of the Center of Mass’ position 

Jerk constraint weight
Sets how much changes in the Center of Mass’ acceleration can potentially affect the animation.

Rotation cost weight
Sets how much the algorithm tries to preserve the character’s original rotation.

Rotation point weight
Sets how much the algorithm tries to preserve the fulcrum points when the character rotates.

Relative delta com cost weight
Sets how much the changes in the relative positions of the Centers of Mass influence the algorithm when the character collides with another character.

Surface Settings

Additional group of settings can be found under the Physics corrector surface tab:

This group of settings is used when the character collides with the floor, or with a collision type surface.

Friction coefficient
Sets the coefficient of friction for the algorithm.

Normal weight
Sets the weight for preserving the character’s position in relation to the surface normal.

Tangent Weight
Sets the weight for preserving the character’s position in relation to the collision surface.

With rotation
If this is enabled, the algorithm would adjust the character’s rotation when the character interacts with the collision surface.

Pin Settings

For swinging motions (when the character is supported by some kind of pin), a different group of settings - Physics Corrector Pin - is used:

Max force direction
Sets the limit for the force’s projection directed from the Center of Mass to the pin’s middle point.
The default value is 5; it is measured in the character’s weights, meaning it is not influenced by the character’s mass or the gravity.

Max force tangent
Same, but for the projection directed along the pin’s surface.
Its default value is 1.

Direction weight
Sets the weight for preserving the position in relation with the direction to the pin’s middle point.

Tangent weight
Sets the weight for preserving the position in relation to the pin’s surface.

With rotation
If this is enabled, the algorithm would adjust the character’s rotation when the character interacts with the pin.

See Also

AutoPhysics

AutoPhyisics Settings