Soft Body Operator Property Editor

| Simulation | Soft Body | Dynamics | Presets

Controls the deformation of non-rigid objects when they are subject to forces and obstacles.

To apply: From the Simulate toolbar, select an object and choose Create Soft Body from Selection.

For more information on soft body in general, see Soft Bodies [ Simulation].

Simulation

Defines the operating parameters of the soft body simulation.

Execution State

Mute	Activates/deactivates the soft body simulation. By muting the soft body simulator, the soft body model returns to its original undeformed state. Temporarily mute it if you want to freely move the playback cursor on the timeline (for example, for inserting keyframes) without running the simulation.

Range

Start Frame	Sets the first frame of the soft body simulation.
End Frame	Sets the last frame of the soft body simulation.
Copy from Scene	Copies the start and end frame values from the scene's timeline to the Start Frame and Duration.
Copy to Scene	Copies the values you set for the Start Frame and Duration to the scene's start and end frame values on the timeline.
Iterations per Frame	The number of iterations executed by the calculation cycle between one frame and the other. High values help the solver to be more precise. If soft body has artifacts, increase this value and play the simulation again.
Save Simulation	When you save the scene, this option calculates the simulation as much as is cached on disk. This information is retrieved when you load the scene again. The cache is optimized to store as little data as possible. If you don't select this option, the computation is executed again when you load the scene.

Soft Body

Defines the deformation attributes of the soft body object.

See Stabilizing a Soft Body Deformation [ Simulation] for more information.

Sampling	Controls the resolution of the lattice around the object's volume that is used in the calculation of the object's deformation. Higher values cause the lattice to more closely resemble the volume of the object to be deformed. While this creates a more realistic result, higher sampling rates take longer to process.
Stiffness	Sets the rigidity of the lattice applied to the object. Higher values cause the object to better resist deformations, although excessively high settings may result in instability. You can set the object to bounce back after a collision and either retain its original form or maintain the deformed appearance after the event. Stiffness also has an effect on Body Friction: a higher Stiffness value causes more "bounciness" as the soft-body object hits an obstacle. While soft bodies can't really be true "rigid bodies", you can get the most rigid results if you set the Stiffness as high as possible and the Sampling as low as possible.
No Stretch	Activates a filtering process at the end of the simulation step that prevents excessive stretching of the springs when there are low values for Stiffness.
Body Mass	Defines the weight of the soft body object. This value has a bearing on how the object interacts with forces and collisions with obstacles, as well as to the stability of the deformation.
Body Friction	Determines how much of the deformed object's energy is absorbed by the obstacle with which it collides. The higher this value, the more friction with the obstacle. This also depends on the Friction value you have set for the obstacle (see Obstacle Property Editor).

Plasticity

Threshold

Defines the plasticity of the object, meaning how much the object can be deformed by soft body. This value sets the point beyond which the effects of the collision can become permanent.

Threshold is the percentage of the original length of the springs. With a value of 1 (100%), if the spring deformation is 100% (both stretching and compression) of the spring's original length, the effect of the collision becomes permanent.

Damping

Controls the degree to which the deformed object recovers its original shape if the deformation is over the Threshold value (see above).

A value of 1 causes the object's deformation to become permanent; a value of 0 simulates a more resilient material, which permits the object to return to its original (predeformed) shape.

Dynamics

Defines how a standard animation of the object cohabits with the deformation of the soft body simulation.

See Applying Soft Body to Animated Objects [ Simulation] for more information.

Use Body Animation	When using soft body only on a region of the model (by clustering it), you can preserve SRT (scale, rotate, translate) transformations on the free area of the model. The movement of the non-clustered area drags the soft body-deformed region. If all of the model is subject to soft body, SRT animations can be taken into account by selecting Solid Body Center.
Inherit Initial Inertia	Preserves the velocity of the object at the first frame of the soft body simulation.
Solid Body Center	Soft body object's center follows the animation, causing the rest of the body to deform as it tries to follow the center.
Soft Cluster Boundary	A cluster of selected points will follow the animation and the rest of the body will deform as it tries to follow the cluster.
Decay	Defines the extension of a region around the object's center or cluster in which the model follows partially the predefined animation and partially the deformation calculated in the simulation.

Presets

Displays a number of soft body presets that you can apply to a soft body object to simulate such objects as a carpet, water balloon, or bouncing ball.

To use the presets:

Select an object to which soft body is already applied.
Open the SoftBodyOp property editor and click one of the buttons on the Presets page.
Calculate the simulation by clicking the Play button in the playback controls.