# Physical Simulation
When a sculpt is movable, or inside a group and one of its parent groups is movable, it will be part of the physics simulation.
# Pseudo-movable: When a sculpt has a physics gadget affecting it, it is considered “pseudo-movable.” It is no longer locked to any containing object and will move independently of it.
As it is not movable, collisions will not be simulated for it.
Collision: When such a sculpt A is near another sculpt B, checks are made between the two for if it is possible for them to collide.
It is possible for them to collide with each other if:
- A is collidable, and B is collidable.
- And B either “collides with” a label of A or has a label that A collides with.
- And B is either not inside a group, or all groups B is a child of “collide with” a label of A.
If it moves slower than a threshold of velocity for long enough (such as coming to rest on a flat surface), and is not being affected by a mover or rotator gadget or similar, it will “sleep” and stop being simulated.
If the sculpt begins moving, or a nearby sculpt moves, and it is found that a collision is possible, or the sculpt begins moving, it will “wake” and continue to be simulated.
# Collision Spheres: Collidable sculpts that are movable or part of a movable group have physics spheres packed within their shape to be used as part of the physics simulation. The more physics spheres are used, the more performance is required to run the physics for that object.
Kinematics is the mathematics used to find a solution to allow several joints to rotate properly.
Forward Kinematics will rotate only child objects depending on the rotation of the parent object. (Tg)
Recorded FK will indicate this by using hash marks from the top-left to the bottom-right, with a green stripe. (Tg)
Note that recording FK actually records the rotation of the joint itself, not the rotation of the object.
Inverse Kinematics will use the desired position of a child object to rotate its parent connected objects (up to 3 in a chain) to allow it, within the set constraints. (Tg)
Recorded IK will indicate this by using hash marks from top-right to bottom-left, with a yellow stripe. (Tg)
Note that only something jointed with at least 2 parent objects in the chain can use IK. (Tg)
(See Convert to FK and Convert to IK.)
When both IK and FK are involved in the same chain, the recorded IK will take precedence. (Tg)
Note that a keyframe that has recorded IK will only be able to record IK for that object. And a keyframe that has recorded FK will only be able to record FK for that object. (Tg)
Use the Move controls to set the position of an object and use IK to rotate parent joints to allow this.
Use the Rotate controls to the rotation of an object—or when used on a jointed object will rotate the object itself which in turn will use FK to rotate connected child objects.
When using the Move controllers, by default they will use IK. Tap the secondary sphere to the primary base to swap between IK and FK.
# Physics Settings
Some settings are common to objects that can be physically simulated.
When on, the sculpt will be physically simulated, reacting as a physical object within the scene. (Pk) Because of this, objects that are movable can fall away from each other, even when they’re inside a group. (Mm)
When being moved by a keyframe, the sculpt appears to lose friction until it reaches the true position the keyframe is moving it to. (Tg)
Note that an object affected by a mover/follower/rotator of some kind will be pseudo-movable. It will not respond to collisions or forces unless it is actually movable. But it will move independently of any group it is contained by. (Tg)
When off, no collisions involving this sculpt will happen.
When on, other collidable sculpts that can be collided with or that can collide with this sculpt will cause collisions if either of the sculpts are movable.
Note that collidability only takes effect when in play mode. While editing and moving things around, you can place collidable objects so that they overlap each other without a problem. (Pk)
# Collides With
Which labels are required on a sculpt to collide with this one.