An animated frame with six degrees of freedom (position + orientation).
A simulated frame with six degrees of freedom, velocity, mass properties … etc.

Collision contact constraints happen between Bodies.

A Body is a combination of a collision shape and one of the three dynamics objects:

  • Actor
  • Rigid
  • Soft

For instance, a rigid can exist without a body and will not get involved in collision constraints. Also two bodies can share the same rigid or the same shape making it possible to share as much data as possible and to handle pre-fractured objects by design in the future.

Inter Fatness
The largest allowed self-collision fatness per points set by the topology. This replaces the specified outer fatness in collision shapes where outer fatness is bigger.

A collection of simulated nodes. A soft has 3 \cdot n degrees of freedom where n is the number of nodes.

Within a Soft, there are multiple maps of primitives providing material constraints between the nodes.

Soft primitive constraining the relative position of two nodes. The length of the segment is governed by visco-elastic forces towards an equilibrium length. The length of the segment is also limited in compression and extension by two hard limits.
Soft primitive that constrains three nodes with surface preservation rules.
Soft primitive that constrains four nodes with volume preservation rules.
Soft angular constraint maintaining the alignment of three nodes.
Soft angular constraint controlling the bending between two triangles formed by four nodes.

Constraints between Actors, Rigids and Softs.

There are atomic joints between Rigid and Actor such as a spherical joint, a prismatic joint, … etc. that can be combined to generate mechanisms.

For example a combination of an Axle angular with a prismatic and a spring, will create a car suspension.

There are also joints between Rigid or Actor and Soft making it possible by analogy to attach flesh to bones: binding joints, welding joints, … etc. For example welding the nodes of a Soft tire with a Rigid alloy will create a wheel that has the framing of a rigid and is partially deformable where the soft body nodes are located.