virtualx-engine/servers/physics_3d/body_pair_3d_sw.cpp
PouleyKetchoupp 448c41a3e4 Godot Physics collisions and solver processed on threads
Use ThreadWorkPool to process physics step tasks in multiple threads. Collisions are all processed in parallel and solving impulses is
processed in parallel for rigid body islands.

Additional changes:
- Proper islands for soft bodies linked to active bodies
- All moving areas are on separate islands (can be parallelized)
- Fix inconsistencies with body islands (Kinematic bodies could link
bodies together or not depending on the processing order)
- Completely prevent static bodies to be active (it could cause islands
to be wrongly created and cause dangerous multi-threading operations as
well as inconsistencies in created islands)
- Apply impulses only on dynamic bodies to avoid unsafe multi-threaded
operations (static bodies can be on multiple islands)
- Removed inverted iterations when populating body islands, it's now
faster in regular order (maybe after fixing inconsistencies)
2021-04-26 18:26:00 -07:00

859 lines
26 KiB
C++

/*************************************************************************/
/* body_pair_3d_sw.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2021 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2021 Godot Engine contributors (cf. AUTHORS.md). */
/* */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the */
/* "Software"), to deal in the Software without restriction, including */
/* without limitation the rights to use, copy, modify, merge, publish, */
/* distribute, sublicense, and/or sell copies of the Software, and to */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions: */
/* */
/* The above copyright notice and this permission notice shall be */
/* included in all copies or substantial portions of the Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
/*************************************************************************/
#include "body_pair_3d_sw.h"
#include "collision_solver_3d_sw.h"
#include "core/os/os.h"
#include "space_3d_sw.h"
/*
#define NO_ACCUMULATE_IMPULSES
#define NO_SPLIT_IMPULSES
#define NO_FRICTION
*/
#define NO_TANGENTIALS
/* BODY PAIR */
//#define ALLOWED_PENETRATION 0.01
#define RELAXATION_TIMESTEPS 3
#define MIN_VELOCITY 0.0001
#define MAX_BIAS_ROTATION (Math_PI / 8)
void BodyPair3DSW::_contact_added_callback(const Vector3 &p_point_A, int p_index_A, const Vector3 &p_point_B, int p_index_B, void *p_userdata) {
BodyPair3DSW *pair = (BodyPair3DSW *)p_userdata;
pair->contact_added_callback(p_point_A, p_index_A, p_point_B, p_index_B);
}
void BodyPair3DSW::contact_added_callback(const Vector3 &p_point_A, int p_index_A, const Vector3 &p_point_B, int p_index_B) {
// check if we already have the contact
//Vector3 local_A = A->get_inv_transform().xform(p_point_A);
//Vector3 local_B = B->get_inv_transform().xform(p_point_B);
Vector3 local_A = A->get_inv_transform().basis.xform(p_point_A);
Vector3 local_B = B->get_inv_transform().basis.xform(p_point_B - offset_B);
int new_index = contact_count;
ERR_FAIL_COND(new_index >= (MAX_CONTACTS + 1));
Contact contact;
contact.acc_normal_impulse = 0;
contact.acc_bias_impulse = 0;
contact.acc_bias_impulse_center_of_mass = 0;
contact.acc_tangent_impulse = Vector3();
contact.index_A = p_index_A;
contact.index_B = p_index_B;
contact.local_A = local_A;
contact.local_B = local_B;
contact.normal = (p_point_A - p_point_B).normalized();
contact.mass_normal = 0; // will be computed in setup()
// attempt to determine if the contact will be reused
real_t contact_recycle_radius = space->get_contact_recycle_radius();
for (int i = 0; i < contact_count; i++) {
Contact &c = contacts[i];
if (c.local_A.distance_squared_to(local_A) < (contact_recycle_radius * contact_recycle_radius) &&
c.local_B.distance_squared_to(local_B) < (contact_recycle_radius * contact_recycle_radius)) {
contact.acc_normal_impulse = c.acc_normal_impulse;
contact.acc_bias_impulse = c.acc_bias_impulse;
contact.acc_bias_impulse_center_of_mass = c.acc_bias_impulse_center_of_mass;
contact.acc_tangent_impulse = c.acc_tangent_impulse;
new_index = i;
break;
}
}
// figure out if the contact amount must be reduced to fit the new contact
if (new_index == MAX_CONTACTS) {
// remove the contact with the minimum depth
int least_deep = -1;
real_t min_depth = 1e10;
for (int i = 0; i <= contact_count; i++) {
Contact &c = (i == contact_count) ? contact : contacts[i];
Vector3 global_A = A->get_transform().basis.xform(c.local_A);
Vector3 global_B = B->get_transform().basis.xform(c.local_B) + offset_B;
Vector3 axis = global_A - global_B;
real_t depth = axis.dot(c.normal);
if (depth < min_depth) {
min_depth = depth;
least_deep = i;
}
}
ERR_FAIL_COND(least_deep == -1);
if (least_deep < contact_count) { //replace the last deep contact by the new one
contacts[least_deep] = contact;
}
return;
}
contacts[new_index] = contact;
if (new_index == contact_count) {
contact_count++;
}
}
void BodyPair3DSW::validate_contacts() {
//make sure to erase contacts that are no longer valid
real_t contact_max_separation = space->get_contact_max_separation();
for (int i = 0; i < contact_count; i++) {
Contact &c = contacts[i];
Vector3 global_A = A->get_transform().basis.xform(c.local_A);
Vector3 global_B = B->get_transform().basis.xform(c.local_B) + offset_B;
Vector3 axis = global_A - global_B;
real_t depth = axis.dot(c.normal);
if (depth < -contact_max_separation || (global_B + c.normal * depth - global_A).length() > contact_max_separation) {
// contact no longer needed, remove
if ((i + 1) < contact_count) {
// swap with the last one
SWAP(contacts[i], contacts[contact_count - 1]);
}
i--;
contact_count--;
}
}
}
bool BodyPair3DSW::_test_ccd(real_t p_step, Body3DSW *p_A, int p_shape_A, const Transform &p_xform_A, Body3DSW *p_B, int p_shape_B, const Transform &p_xform_B) {
Vector3 motion = p_A->get_linear_velocity() * p_step;
real_t mlen = motion.length();
if (mlen < CMP_EPSILON) {
return false;
}
Vector3 mnormal = motion / mlen;
real_t min, max;
p_A->get_shape(p_shape_A)->project_range(mnormal, p_xform_A, min, max);
bool fast_object = mlen > (max - min) * 0.3; //going too fast in that direction
if (!fast_object) { //did it move enough in this direction to even attempt raycast? let's say it should move more than 1/3 the size of the object in that axis
return false;
}
//cast a segment from support in motion normal, in the same direction of motion by motion length
//support is the worst case collision point, so real collision happened before
Vector3 s = p_A->get_shape(p_shape_A)->get_support(p_xform_A.basis.xform(mnormal).normalized());
Vector3 from = p_xform_A.xform(s);
Vector3 to = from + motion;
Transform from_inv = p_xform_B.affine_inverse();
Vector3 local_from = from_inv.xform(from - mnormal * mlen * 0.1); //start from a little inside the bounding box
Vector3 local_to = from_inv.xform(to);
Vector3 rpos, rnorm;
if (!p_B->get_shape(p_shape_B)->intersect_segment(local_from, local_to, rpos, rnorm)) {
return false;
}
//shorten the linear velocity so it does not hit, but gets close enough, next frame will hit softly or soft enough
Vector3 hitpos = p_xform_B.xform(rpos);
real_t newlen = hitpos.distance_to(from) - (max - min) * 0.01;
p_A->set_linear_velocity((mnormal * newlen) / p_step);
return true;
}
real_t combine_bounce(Body3DSW *A, Body3DSW *B) {
return CLAMP(A->get_bounce() + B->get_bounce(), 0, 1);
}
real_t combine_friction(Body3DSW *A, Body3DSW *B) {
return ABS(MIN(A->get_friction(), B->get_friction()));
}
bool BodyPair3DSW::setup(real_t p_step) {
dynamic_A = (A->get_mode() > PhysicsServer3D::BODY_MODE_KINEMATIC);
dynamic_B = (B->get_mode() > PhysicsServer3D::BODY_MODE_KINEMATIC);
if (!A->test_collision_mask(B) || A->has_exception(B->get_self()) || B->has_exception(A->get_self())) {
collided = false;
return false;
}
report_contacts_only = false;
if (!dynamic_A && !dynamic_B) {
if ((A->get_max_contacts_reported() > 0) || (B->get_max_contacts_reported() > 0)) {
report_contacts_only = true;
} else {
collided = false;
return false;
}
}
if (A->is_shape_set_as_disabled(shape_A) || B->is_shape_set_as_disabled(shape_B)) {
collided = false;
return false;
}
offset_B = B->get_transform().get_origin() - A->get_transform().get_origin();
validate_contacts();
const Vector3 &offset_A = A->get_transform().get_origin();
Transform xform_Au = Transform(A->get_transform().basis, Vector3());
Transform xform_A = xform_Au * A->get_shape_transform(shape_A);
Transform xform_Bu = B->get_transform();
xform_Bu.origin -= offset_A;
Transform xform_B = xform_Bu * B->get_shape_transform(shape_B);
Shape3DSW *shape_A_ptr = A->get_shape(shape_A);
Shape3DSW *shape_B_ptr = B->get_shape(shape_B);
collided = CollisionSolver3DSW::solve_static(shape_A_ptr, xform_A, shape_B_ptr, xform_B, _contact_added_callback, this, &sep_axis);
if (!collided) {
//test ccd (currently just a raycast)
if (A->is_continuous_collision_detection_enabled() && dynamic_A && !dynamic_B) {
_test_ccd(p_step, A, shape_A, xform_A, B, shape_B, xform_B);
}
if (B->is_continuous_collision_detection_enabled() && dynamic_B && !dynamic_A) {
_test_ccd(p_step, B, shape_B, xform_B, A, shape_A, xform_A);
}
return false;
}
return true;
}
bool BodyPair3DSW::pre_solve(real_t p_step) {
if (!collided) {
return false;
}
real_t max_penetration = space->get_contact_max_allowed_penetration();
real_t bias = (real_t)0.3;
Shape3DSW *shape_A_ptr = A->get_shape(shape_A);
Shape3DSW *shape_B_ptr = B->get_shape(shape_B);
if (shape_A_ptr->get_custom_bias() || shape_B_ptr->get_custom_bias()) {
if (shape_A_ptr->get_custom_bias() == 0) {
bias = shape_B_ptr->get_custom_bias();
} else if (shape_B_ptr->get_custom_bias() == 0) {
bias = shape_A_ptr->get_custom_bias();
} else {
bias = (shape_B_ptr->get_custom_bias() + shape_A_ptr->get_custom_bias()) * 0.5;
}
}
real_t inv_dt = 1.0 / p_step;
bool do_process = false;
const Basis &basis_A = A->get_transform().basis;
const Basis &basis_B = B->get_transform().basis;
for (int i = 0; i < contact_count; i++) {
Contact &c = contacts[i];
c.active = false;
Vector3 global_A = basis_A.xform(c.local_A);
Vector3 global_B = basis_B.xform(c.local_B) + offset_B;
Vector3 axis = global_A - global_B;
real_t depth = axis.dot(c.normal);
if (depth <= 0) {
continue;
}
#ifdef DEBUG_ENABLED
if (space->is_debugging_contacts()) {
const Vector3 &offset_A = A->get_transform().get_origin();
space->add_debug_contact(global_A + offset_A);
space->add_debug_contact(global_B + offset_A);
}
#endif
c.rA = global_A - A->get_center_of_mass();
c.rB = global_B - B->get_center_of_mass() - offset_B;
// contact query reporting...
if (A->can_report_contacts()) {
Vector3 crA = A->get_angular_velocity().cross(c.rA) + A->get_linear_velocity();
A->add_contact(global_A, -c.normal, depth, shape_A, global_B, shape_B, B->get_instance_id(), B->get_self(), crA);
}
if (B->can_report_contacts()) {
Vector3 crB = B->get_angular_velocity().cross(c.rB) + B->get_linear_velocity();
B->add_contact(global_B, c.normal, depth, shape_B, global_A, shape_A, A->get_instance_id(), A->get_self(), crB);
}
if (report_contacts_only) {
collided = false;
continue;
}
c.active = true;
do_process = true;
// Precompute normal mass, tangent mass, and bias.
Vector3 inertia_A = A->get_inv_inertia_tensor().xform(c.rA.cross(c.normal));
Vector3 inertia_B = B->get_inv_inertia_tensor().xform(c.rB.cross(c.normal));
real_t kNormal = A->get_inv_mass() + B->get_inv_mass();
kNormal += c.normal.dot(inertia_A.cross(c.rA)) + c.normal.dot(inertia_B.cross(c.rB));
c.mass_normal = 1.0f / kNormal;
c.bias = -bias * inv_dt * MIN(0.0f, -depth + max_penetration);
c.depth = depth;
Vector3 j_vec = c.normal * c.acc_normal_impulse + c.acc_tangent_impulse;
if (dynamic_A) {
A->apply_impulse(-j_vec, c.rA + A->get_center_of_mass());
}
if (dynamic_B) {
B->apply_impulse(j_vec, c.rB + B->get_center_of_mass());
}
c.acc_bias_impulse = 0;
c.acc_bias_impulse_center_of_mass = 0;
c.bounce = combine_bounce(A, B);
if (c.bounce) {
Vector3 crA = A->get_angular_velocity().cross(c.rA);
Vector3 crB = B->get_angular_velocity().cross(c.rB);
Vector3 dv = B->get_linear_velocity() + crB - A->get_linear_velocity() - crA;
//normal impule
c.bounce = c.bounce * dv.dot(c.normal);
}
}
return do_process;
}
void BodyPair3DSW::solve(real_t p_step) {
if (!collided) {
return;
}
const real_t max_bias_av = MAX_BIAS_ROTATION / p_step;
for (int i = 0; i < contact_count; i++) {
Contact &c = contacts[i];
if (!c.active) {
continue;
}
c.active = false; //try to deactivate, will activate itself if still needed
//bias impulse
Vector3 crbA = A->get_biased_angular_velocity().cross(c.rA);
Vector3 crbB = B->get_biased_angular_velocity().cross(c.rB);
Vector3 dbv = B->get_biased_linear_velocity() + crbB - A->get_biased_linear_velocity() - crbA;
real_t vbn = dbv.dot(c.normal);
if (Math::abs(-vbn + c.bias) > MIN_VELOCITY) {
real_t jbn = (-vbn + c.bias) * c.mass_normal;
real_t jbnOld = c.acc_bias_impulse;
c.acc_bias_impulse = MAX(jbnOld + jbn, 0.0f);
Vector3 jb = c.normal * (c.acc_bias_impulse - jbnOld);
if (dynamic_A) {
A->apply_bias_impulse(-jb, c.rA + A->get_center_of_mass(), max_bias_av);
}
if (dynamic_B) {
B->apply_bias_impulse(jb, c.rB + B->get_center_of_mass(), max_bias_av);
}
crbA = A->get_biased_angular_velocity().cross(c.rA);
crbB = B->get_biased_angular_velocity().cross(c.rB);
dbv = B->get_biased_linear_velocity() + crbB - A->get_biased_linear_velocity() - crbA;
vbn = dbv.dot(c.normal);
if (Math::abs(-vbn + c.bias) > MIN_VELOCITY) {
real_t jbn_com = (-vbn + c.bias) / (A->get_inv_mass() + B->get_inv_mass());
real_t jbnOld_com = c.acc_bias_impulse_center_of_mass;
c.acc_bias_impulse_center_of_mass = MAX(jbnOld_com + jbn_com, 0.0f);
Vector3 jb_com = c.normal * (c.acc_bias_impulse_center_of_mass - jbnOld_com);
if (dynamic_A) {
A->apply_bias_impulse(-jb_com, A->get_center_of_mass(), 0.0f);
}
if (dynamic_B) {
B->apply_bias_impulse(jb_com, B->get_center_of_mass(), 0.0f);
}
}
c.active = true;
}
Vector3 crA = A->get_angular_velocity().cross(c.rA);
Vector3 crB = B->get_angular_velocity().cross(c.rB);
Vector3 dv = B->get_linear_velocity() + crB - A->get_linear_velocity() - crA;
//normal impulse
real_t vn = dv.dot(c.normal);
if (Math::abs(vn) > MIN_VELOCITY) {
real_t jn = -(c.bounce + vn) * c.mass_normal;
real_t jnOld = c.acc_normal_impulse;
c.acc_normal_impulse = MAX(jnOld + jn, 0.0f);
Vector3 j = c.normal * (c.acc_normal_impulse - jnOld);
if (dynamic_A) {
A->apply_impulse(-j, c.rA + A->get_center_of_mass());
}
if (dynamic_B) {
B->apply_impulse(j, c.rB + B->get_center_of_mass());
}
c.active = true;
}
//friction impulse
real_t friction = combine_friction(A, B);
Vector3 lvA = A->get_linear_velocity() + A->get_angular_velocity().cross(c.rA);
Vector3 lvB = B->get_linear_velocity() + B->get_angular_velocity().cross(c.rB);
Vector3 dtv = lvB - lvA;
real_t tn = c.normal.dot(dtv);
// tangential velocity
Vector3 tv = dtv - c.normal * tn;
real_t tvl = tv.length();
if (tvl > MIN_VELOCITY) {
tv /= tvl;
Vector3 temp1 = A->get_inv_inertia_tensor().xform(c.rA.cross(tv));
Vector3 temp2 = B->get_inv_inertia_tensor().xform(c.rB.cross(tv));
real_t t = -tvl /
(A->get_inv_mass() + B->get_inv_mass() + tv.dot(temp1.cross(c.rA) + temp2.cross(c.rB)));
Vector3 jt = t * tv;
Vector3 jtOld = c.acc_tangent_impulse;
c.acc_tangent_impulse += jt;
real_t fi_len = c.acc_tangent_impulse.length();
real_t jtMax = c.acc_normal_impulse * friction;
if (fi_len > CMP_EPSILON && fi_len > jtMax) {
c.acc_tangent_impulse *= jtMax / fi_len;
}
jt = c.acc_tangent_impulse - jtOld;
if (dynamic_A) {
A->apply_impulse(-jt, c.rA + A->get_center_of_mass());
}
if (dynamic_B) {
B->apply_impulse(jt, c.rB + B->get_center_of_mass());
}
c.active = true;
}
}
}
BodyPair3DSW::BodyPair3DSW(Body3DSW *p_A, int p_shape_A, Body3DSW *p_B, int p_shape_B) :
BodyContact3DSW(_arr, 2) {
A = p_A;
B = p_B;
shape_A = p_shape_A;
shape_B = p_shape_B;
space = A->get_space();
A->add_constraint(this, 0);
B->add_constraint(this, 1);
}
BodyPair3DSW::~BodyPair3DSW() {
A->remove_constraint(this);
B->remove_constraint(this);
}
void BodySoftBodyPair3DSW::_contact_added_callback(const Vector3 &p_point_A, int p_index_A, const Vector3 &p_point_B, int p_index_B, void *p_userdata) {
BodySoftBodyPair3DSW *pair = (BodySoftBodyPair3DSW *)p_userdata;
pair->contact_added_callback(p_point_A, p_index_A, p_point_B, p_index_B);
}
void BodySoftBodyPair3DSW::contact_added_callback(const Vector3 &p_point_A, int p_index_A, const Vector3 &p_point_B, int p_index_B) {
Vector3 local_A = body->get_inv_transform().xform(p_point_A);
Vector3 local_B = p_point_B - soft_body->get_node_position(p_index_B);
Contact contact;
contact.index_A = p_index_A;
contact.index_B = p_index_B;
contact.acc_normal_impulse = 0;
contact.acc_bias_impulse = 0;
contact.acc_bias_impulse_center_of_mass = 0;
contact.acc_tangent_impulse = Vector3();
contact.local_A = local_A;
contact.local_B = local_B;
contact.normal = (p_point_A - p_point_B).normalized();
contact.mass_normal = 0;
// Attempt to determine if the contact will be reused.
real_t contact_recycle_radius = space->get_contact_recycle_radius();
uint32_t contact_count = contacts.size();
for (uint32_t contact_index = 0; contact_index < contact_count; ++contact_index) {
Contact &c = contacts[contact_index];
if (c.index_B == p_index_B) {
if (c.local_A.distance_squared_to(local_A) < (contact_recycle_radius * contact_recycle_radius) &&
c.local_B.distance_squared_to(local_B) < (contact_recycle_radius * contact_recycle_radius)) {
contact.acc_normal_impulse = c.acc_normal_impulse;
contact.acc_bias_impulse = c.acc_bias_impulse;
contact.acc_bias_impulse_center_of_mass = c.acc_bias_impulse_center_of_mass;
contact.acc_tangent_impulse = c.acc_tangent_impulse;
}
c = contact;
return;
}
}
contacts.push_back(contact);
}
void BodySoftBodyPair3DSW::validate_contacts() {
// Make sure to erase contacts that are no longer valid.
const Transform &transform_A = body->get_transform();
real_t contact_max_separation = space->get_contact_max_separation();
uint32_t contact_count = contacts.size();
for (uint32_t contact_index = 0; contact_index < contact_count; ++contact_index) {
Contact &c = contacts[contact_index];
Vector3 global_A = transform_A.xform(c.local_A);
Vector3 global_B = soft_body->get_node_position(c.index_B) + c.local_B;
Vector3 axis = global_A - global_B;
real_t depth = axis.dot(c.normal);
if (depth < -contact_max_separation || (global_B + c.normal * depth - global_A).length() > contact_max_separation) {
// Contact no longer needed, remove.
if ((contact_index + 1) < contact_count) {
// Swap with the last one.
SWAP(c, contacts[contact_count - 1]);
}
contact_index--;
contact_count--;
}
}
contacts.resize(contact_count);
}
bool BodySoftBodyPair3DSW::setup(real_t p_step) {
body_dynamic = (body->get_mode() > PhysicsServer3D::BODY_MODE_KINEMATIC);
if (!body->test_collision_mask(soft_body) || body->has_exception(soft_body->get_self()) || soft_body->has_exception(body->get_self())) {
collided = false;
return false;
}
if (body->is_shape_set_as_disabled(body_shape)) {
collided = false;
return false;
}
const Transform &xform_Au = body->get_transform();
Transform xform_A = xform_Au * body->get_shape_transform(body_shape);
Transform xform_Bu = soft_body->get_transform();
Transform xform_B = xform_Bu * soft_body->get_shape_transform(0);
validate_contacts();
Shape3DSW *shape_A_ptr = body->get_shape(body_shape);
Shape3DSW *shape_B_ptr = soft_body->get_shape(0);
collided = CollisionSolver3DSW::solve_static(shape_A_ptr, xform_A, shape_B_ptr, xform_B, _contact_added_callback, this, &sep_axis);
return collided;
}
bool BodySoftBodyPair3DSW::pre_solve(real_t p_step) {
if (!collided) {
return false;
}
real_t max_penetration = space->get_contact_max_allowed_penetration();
real_t bias = (real_t)0.3;
Shape3DSW *shape_A_ptr = body->get_shape(body_shape);
if (shape_A_ptr->get_custom_bias()) {
bias = shape_A_ptr->get_custom_bias();
}
real_t inv_dt = 1.0 / p_step;
bool do_process = false;
const Transform &transform_A = body->get_transform();
uint32_t contact_count = contacts.size();
for (uint32_t contact_index = 0; contact_index < contact_count; ++contact_index) {
Contact &c = contacts[contact_index];
c.active = false;
real_t node_inv_mass = soft_body->get_node_inv_mass(c.index_B);
if (node_inv_mass == 0.0) {
continue;
}
Vector3 global_A = transform_A.xform(c.local_A);
Vector3 global_B = soft_body->get_node_position(c.index_B) + c.local_B;
Vector3 axis = global_A - global_B;
real_t depth = axis.dot(c.normal);
if (depth <= 0) {
continue;
}
c.active = true;
do_process = true;
#ifdef DEBUG_ENABLED
if (space->is_debugging_contacts()) {
space->add_debug_contact(global_A);
space->add_debug_contact(global_B);
}
#endif
c.rA = global_A - transform_A.origin - body->get_center_of_mass();
c.rB = global_B;
if (body->can_report_contacts()) {
Vector3 crA = body->get_angular_velocity().cross(c.rA) + body->get_linear_velocity();
body->add_contact(global_A, -c.normal, depth, body_shape, global_B, 0, soft_body->get_instance_id(), soft_body->get_self(), crA);
}
if (body_dynamic) {
body->set_active(true);
}
// Precompute normal mass, tangent mass, and bias.
Vector3 inertia_A = body->get_inv_inertia_tensor().xform(c.rA.cross(c.normal));
real_t kNormal = body->get_inv_mass() + node_inv_mass;
kNormal += c.normal.dot(inertia_A.cross(c.rA));
c.mass_normal = 1.0f / kNormal;
c.bias = -bias * inv_dt * MIN(0.0f, -depth + max_penetration);
c.depth = depth;
Vector3 j_vec = c.normal * c.acc_normal_impulse + c.acc_tangent_impulse;
if (body_dynamic) {
body->apply_impulse(-j_vec, c.rA + body->get_center_of_mass());
}
soft_body->apply_node_impulse(c.index_B, j_vec);
c.acc_bias_impulse = 0;
c.acc_bias_impulse_center_of_mass = 0;
c.bounce = body->get_bounce();
if (c.bounce) {
Vector3 crA = body->get_angular_velocity().cross(c.rA);
Vector3 dv = soft_body->get_node_velocity(c.index_B) - body->get_linear_velocity() - crA;
// Normal impulse.
c.bounce = c.bounce * dv.dot(c.normal);
}
}
return do_process;
}
void BodySoftBodyPair3DSW::solve(real_t p_step) {
if (!collided) {
return;
}
const real_t max_bias_av = MAX_BIAS_ROTATION / p_step;
uint32_t contact_count = contacts.size();
for (uint32_t contact_index = 0; contact_index < contact_count; ++contact_index) {
Contact &c = contacts[contact_index];
if (!c.active) {
continue;
}
c.active = false;
// Bias impulse.
Vector3 crbA = body->get_biased_angular_velocity().cross(c.rA);
Vector3 dbv = soft_body->get_node_biased_velocity(c.index_B) - body->get_biased_linear_velocity() - crbA;
real_t vbn = dbv.dot(c.normal);
if (Math::abs(-vbn + c.bias) > MIN_VELOCITY) {
real_t jbn = (-vbn + c.bias) * c.mass_normal;
real_t jbnOld = c.acc_bias_impulse;
c.acc_bias_impulse = MAX(jbnOld + jbn, 0.0f);
Vector3 jb = c.normal * (c.acc_bias_impulse - jbnOld);
if (body_dynamic) {
body->apply_bias_impulse(-jb, c.rA + body->get_center_of_mass(), max_bias_av);
}
soft_body->apply_node_bias_impulse(c.index_B, jb);
crbA = body->get_biased_angular_velocity().cross(c.rA);
dbv = soft_body->get_node_biased_velocity(c.index_B) - body->get_biased_linear_velocity() - crbA;
vbn = dbv.dot(c.normal);
if (Math::abs(-vbn + c.bias) > MIN_VELOCITY) {
real_t jbn_com = (-vbn + c.bias) / (body->get_inv_mass() + soft_body->get_node_inv_mass(c.index_B));
real_t jbnOld_com = c.acc_bias_impulse_center_of_mass;
c.acc_bias_impulse_center_of_mass = MAX(jbnOld_com + jbn_com, 0.0f);
Vector3 jb_com = c.normal * (c.acc_bias_impulse_center_of_mass - jbnOld_com);
if (body_dynamic) {
body->apply_bias_impulse(-jb_com, body->get_center_of_mass(), 0.0f);
}
soft_body->apply_node_bias_impulse(c.index_B, jb_com);
}
c.active = true;
}
Vector3 crA = body->get_angular_velocity().cross(c.rA);
Vector3 dv = soft_body->get_node_velocity(c.index_B) - body->get_linear_velocity() - crA;
// Normal impulse.
real_t vn = dv.dot(c.normal);
if (Math::abs(vn) > MIN_VELOCITY) {
real_t jn = -(c.bounce + vn) * c.mass_normal;
real_t jnOld = c.acc_normal_impulse;
c.acc_normal_impulse = MAX(jnOld + jn, 0.0f);
Vector3 j = c.normal * (c.acc_normal_impulse - jnOld);
if (body_dynamic) {
body->apply_impulse(-j, c.rA + body->get_center_of_mass());
}
soft_body->apply_node_impulse(c.index_B, j);
c.active = true;
}
// Friction impulse.
real_t friction = body->get_friction();
Vector3 lvA = body->get_linear_velocity() + body->get_angular_velocity().cross(c.rA);
Vector3 lvB = soft_body->get_node_velocity(c.index_B);
Vector3 dtv = lvB - lvA;
real_t tn = c.normal.dot(dtv);
// Tangential velocity.
Vector3 tv = dtv - c.normal * tn;
real_t tvl = tv.length();
if (tvl > MIN_VELOCITY) {
tv /= tvl;
Vector3 temp1 = body->get_inv_inertia_tensor().xform(c.rA.cross(tv));
real_t t = -tvl /
(body->get_inv_mass() + soft_body->get_node_inv_mass(c.index_B) + tv.dot(temp1.cross(c.rA)));
Vector3 jt = t * tv;
Vector3 jtOld = c.acc_tangent_impulse;
c.acc_tangent_impulse += jt;
real_t fi_len = c.acc_tangent_impulse.length();
real_t jtMax = c.acc_normal_impulse * friction;
if (fi_len > CMP_EPSILON && fi_len > jtMax) {
c.acc_tangent_impulse *= jtMax / fi_len;
}
jt = c.acc_tangent_impulse - jtOld;
if (body_dynamic) {
body->apply_impulse(-jt, c.rA + body->get_center_of_mass());
}
soft_body->apply_node_impulse(c.index_B, jt);
c.active = true;
}
}
}
BodySoftBodyPair3DSW::BodySoftBodyPair3DSW(Body3DSW *p_A, int p_shape_A, SoftBody3DSW *p_B) :
BodyContact3DSW(&body, 1) {
body = p_A;
soft_body = p_B;
body_shape = p_shape_A;
space = p_A->get_space();
body->add_constraint(this, 0);
soft_body->add_constraint(this);
}
BodySoftBodyPair3DSW::~BodySoftBodyPair3DSW() {
body->remove_constraint(this);
soft_body->remove_constraint(this);
}