Solver Iterations and Collision Margin (New for 5)

In the Stiffness, Bending Constraint and Solver Iterations section, you read that the Solver Iterations calculates the animation details of a soft body. But actually, it mostly calculates the details when collision happens. Therefore, the margin from the surfaces of the soft body decides the details as well. You can set the collision behaviors in the Collision Settings section.

Soft vs. Rigid Collision & Soft vs. Soft Collision

This setting must be enabled if you want a specific soft body to interact with other rigid bodies. Otherwise the soft body will penetrate all rigid bodies when they intersect.

When this setting is on more system resources will be consumed therefore, disable it when soft bodies are isolated from all other rigid bodies.

Soft vs. Rigid Collision = Off

The soft body goes through the rigid body

Soft vs. Rigid Collision = On

Collision Margin

Collision Margin is the reaction range from the surface of a soft body during collision. The higher the value, the farther the soft body starts the collision behavior. This is useful especially when the sharp edges of the collided object (mostly rigid bodies) go through the soft body.

Collision Margin = 10

The edges of the rigid body penetrate the soft body.

Collision Margin = 20

The soft body slightly moves away from the surface of the rigid body.

If the Collision Margin is set too high, then the soft body will be too much away from the collided objects, which will cause an unnatural result.

Collision Margin = 99

The soft body is too far away from the rigid body.

Using Collision Margin with Lift to Avoid Penetrating

In addition to setting the Collision Margin to have the soft body interact with the rigid body from a specific distance, you may also combine the use of Lift setting.

The Lift setting affects the soft body to fall down softly and gently, which may help iClone by giving it more time to do better collision calculations for soft bodies and rigid bodies.

Collision Margin = 13

Lift = 0

Collision Margin = 13

Lift = 2500