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First working version of non-linear CCD based on single-substep motion-clamping.

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This commit is contained in:
Crozet Sébastien
2021-03-26 18:16:27 +01:00
parent 326469a1df
commit 97157c9423
29 changed files with 696 additions and 109 deletions
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112
src/dynamics/rigid_body.rs
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@@ -36,6 +36,7 @@ bitflags::bitflags! {
const ROTATION_LOCKED_X = 1 << 1;
const ROTATION_LOCKED_Y = 1 << 2;
const ROTATION_LOCKED_Z = 1 << 3;
const CCD_ENABLED = 1 << 4;
}
}
@@ -58,7 +59,16 @@ bitflags::bitflags! {
pub struct RigidBody {
/// The world-space position of the rigid-body.
pub(crate) position: Isometry<Real>,
pub(crate) predicted_position: Isometry<Real>,
/// The next position of the rigid-body.
///
/// At the beginning of the timestep, and when the
/// timestep is complete we must have position == next_position
/// except for kinematic bodies.
///
/// The next_position is updated after the velocity and position
/// resolution. Then it is either validated (ie. we set position := set_position)
/// or clamped by CCD.
pub(crate) next_position: Isometry<Real>,
/// The local mass properties of the rigid-body.
pub(crate) mass_properties: MassProperties,
/// The world-space center of mass of the rigid-body.
@@ -76,6 +86,10 @@ pub struct RigidBody {
pub linear_damping: Real,
/// Damping factor for gradually slowing down the angular motion of the rigid-body.
pub angular_damping: Real,
/// The maximum linear velocity this rigid-body can reach.
pub max_linear_velocity: Real,
/// The maximum angular velocity this rigid-body can reach.
pub max_angular_velocity: Real,
/// Accumulation of external forces (only for dynamic bodies).
pub(crate) force: Vector<Real>,
/// Accumulation of external torques (only for dynamic bodies).
@@ -97,13 +111,14 @@ pub struct RigidBody {
dominance_group: i8,
/// User-defined data associated to this rigid-body.
pub user_data: u128,
pub(crate) ccd_thickness: Real,
}
impl RigidBody {
fn new() -> Self {
Self {
position: Isometry::identity(),
predicted_position: Isometry::identity(),
next_position: Isometry::identity(),
mass_properties: MassProperties::zero(),
world_com: Point::origin(),
effective_inv_mass: 0.0,
@@ -115,6 +130,8 @@ impl RigidBody {
gravity_scale: 1.0,
linear_damping: 0.0,
angular_damping: 0.0,
max_linear_velocity: Real::MAX,
max_angular_velocity: 100.0,
colliders: Vec::new(),
activation: ActivationStatus::new_active(),
joint_graph_index: InteractionGraph::<(), ()>::invalid_graph_index(),
@@ -127,6 +144,7 @@ impl RigidBody {
body_status: BodyStatus::Dynamic,
dominance_group: 0,
user_data: 0,
ccd_thickness: Real::MAX,
}
}
@@ -176,6 +194,20 @@ impl RigidBody {
}
}
/// Enables of disable CCD (continuous collision-detection) for this rigid-body.
pub fn enable_ccd(&mut self, enabled: bool) {
self.flags.set(RigidBodyFlags::CCD_ENABLED, enabled)
}
/// Is CCD (continous collision-detection) enabled for this rigid-body?
pub fn is_ccd_enabled(&self) -> bool {
self.flags.contains(RigidBodyFlags::CCD_ENABLED)
}
pub(crate) fn should_resolve_ccd(&self, dt: Real) -> bool {
self.is_ccd_enabled() && self.is_dynamic() && self.linvel.norm() * dt > self.ccd_thickness
}
/// Sets the rigid-body's mass properties.
///
/// If `wake_up` is `true` then the rigid-body will be woken up if it was
@@ -228,8 +260,8 @@ impl RigidBody {
/// If this rigid-body is kinematic this value is set by the `set_next_kinematic_position`
/// method and is used for estimating the kinematic body velocity at the next timestep.
/// For non-kinematic bodies, this value is currently unspecified.
pub fn predicted_position(&self) -> &Isometry<Real> {
&self.predicted_position
pub fn next_position(&self) -> &Isometry<Real> {
&self.next_position
}
/// The scale factor applied to the gravity affecting this rigid-body.
@@ -254,6 +286,8 @@ impl RigidBody {
true,
);
self.ccd_thickness = self.ccd_thickness.min(coll.shape().ccd_thickness());
let mass_properties = coll
.mass_properties()
.transform_by(coll.position_wrt_parent());
@@ -265,8 +299,8 @@ impl RigidBody {
pub(crate) fn update_colliders_positions(&mut self, colliders: &mut ColliderSet) {
for handle in &self.colliders {
let collider = &mut colliders[*handle];
collider.prev_position = self.position;
collider.position = self.position * collider.delta;
collider.predicted_position = self.predicted_position * collider.delta;
}
}
@@ -331,18 +365,39 @@ impl RigidBody {
!self.linvel.is_zero() || !self.angvel.is_zero()
}
fn integrate_velocity(&self, dt: Real) -> Isometry<Real> {
pub(crate) fn integrate_velocity(&self, dt: Real) -> Isometry<Real> {
let com = self.position * self.mass_properties.local_com;
let shift = Translation::from(com.coords);
shift * Isometry::new(self.linvel * dt, self.angvel * dt) * shift.inverse()
}
pub(crate) fn integrate(&mut self, dt: Real) {
// TODO: do we want to apply damping before or after the velocity integration?
self.linvel *= 1.0 / (1.0 + dt * self.linear_damping);
self.angvel *= 1.0 / (1.0 + dt * self.angular_damping);
pub(crate) fn position_at_time(&self, dt: Real) -> Isometry<Real> {
self.integrate_velocity(dt) * self.position
}
self.position = self.integrate_velocity(dt) * self.position;
pub(crate) fn integrate_next_position(&mut self, dt: Real, apply_damping: bool) {
// TODO: do we want to apply damping before or after the velocity integration?
if apply_damping {
self.linvel *= 1.0 / (1.0 + dt * self.linear_damping);
self.angvel *= 1.0 / (1.0 + dt * self.angular_damping);
// self.linvel = self.linvel.cap_magnitude(self.max_linear_velocity);
// #[cfg(feature = "dim2")]
// {
// self.angvel = na::clamp(
// self.angvel,
// -self.max_angular_velocity,
// self.max_angular_velocity,
// );
// }
// #[cfg(feature = "dim3")]
// {
// self.angvel = self.angvel.cap_magnitude(self.max_angular_velocity);
// }
}
self.next_position = self.integrate_velocity(dt) * self.position;
let _ = self.next_position.rotation.renormalize();
}
/// The linear velocity of this rigid-body.
@@ -416,7 +471,8 @@ impl RigidBody {
/// put to sleep because it did not move for a while.
pub fn set_position(&mut self, pos: Isometry<Real>, wake_up: bool) {
self.changes.insert(RigidBodyChanges::POSITION);
self.set_position_internal(pos);
self.position = pos;
self.next_position = pos;
// TODO: Do we really need to check that the body isn't dynamic?
if wake_up && self.is_dynamic() {
@@ -424,24 +480,19 @@ impl RigidBody {
}
}
pub(crate) fn set_position_internal(&mut self, pos: Isometry<Real>) {
self.position = pos;
// TODO: update the predicted position for dynamic bodies too?
if self.is_static() || self.is_kinematic() {
self.predicted_position = pos;
}
pub(crate) fn set_next_position(&mut self, pos: Isometry<Real>) {
self.next_position = pos;
}
/// If this rigid body is kinematic, sets its future position after the next timestep integration.
pub fn set_next_kinematic_position(&mut self, pos: Isometry<Real>) {
if self.is_kinematic() {
self.predicted_position = pos;
self.next_position = pos;
}
}
pub(crate) fn compute_velocity_from_predicted_position(&mut self, inv_dt: Real) {
let dpos = self.predicted_position * self.position.inverse();
pub(crate) fn compute_velocity_from_next_position(&mut self, inv_dt: Real) {
let dpos = self.next_position * self.position.inverse();
#[cfg(feature = "dim2")]
{
self.angvel = dpos.rotation.angle() * inv_dt;
@@ -453,8 +504,8 @@ impl RigidBody {
self.linvel = dpos.translation.vector * inv_dt;
}
pub(crate) fn update_predicted_position(&mut self, dt: Real) {
self.predicted_position = self.integrate_velocity(dt) * self.position;
pub(crate) fn update_next_position(&mut self, dt: Real) {
self.next_position = self.integrate_velocity(dt) * self.position;
}
pub(crate) fn update_world_mass_properties(&mut self) {
@@ -666,6 +717,7 @@ pub struct RigidBodyBuilder {
mass_properties: MassProperties,
can_sleep: bool,
sleeping: bool,
ccd_enabled: bool,
dominance_group: i8,
user_data: u128,
}
@@ -685,6 +737,7 @@ impl RigidBodyBuilder {
mass_properties: MassProperties::zero(),
can_sleep: true,
sleeping: false,
ccd_enabled: false,
dominance_group: 0,
user_data: 0,
}
@@ -888,6 +941,12 @@ impl RigidBodyBuilder {
self
}
/// Enabled continuous collision-detection for this rigid-body.
pub fn ccd_enabled(mut self, enabled: bool) -> Self {
self.ccd_enabled = enabled;
self
}
/// Sets whether or not the rigid-body is to be created asleep.
pub fn sleeping(mut self, sleeping: bool) -> Self {
self.sleeping = sleeping;
@@ -897,8 +956,8 @@ impl RigidBodyBuilder {
/// Build a new rigid-body with the parameters configured with this builder.
pub fn build(&self) -> RigidBody {
let mut rb = RigidBody::new();
rb.predicted_position = self.position; // FIXME: compute the correct value?
rb.set_position_internal(self.position);
rb.next_position = self.position; // FIXME: compute the correct value?
rb.position = self.position;
rb.linvel = self.linvel;
rb.angvel = self.angvel;
rb.body_status = self.body_status;
@@ -909,6 +968,7 @@ impl RigidBodyBuilder {
rb.gravity_scale = self.gravity_scale;
rb.flags = self.flags;
rb.dominance_group = self.dominance_group;
rb.enable_ccd(self.ccd_enabled);
if self.can_sleep && self.sleeping {
rb.sleep();