mirror of
https://github.com/godotengine/godot.git
synced 2024-12-27 11:24:59 +08:00
5cbc7149a1
Changed the algorithm for solving contacts to keep previous contacts as long as they are under the max separation threshold to keep contact impulses more consistent and contacts more stable. Also made 2D consistent with 3D and changed some default parameters: -Contact bias is now 0.8 instead of 0.3 to avoid springy contacts -Solver iterations are 16 instead of 8 by default for better stability Performance considerations: Tested with stress tests that include lots of contacts from overlapping bodies. 3D: There's no measurable difference in performance. 2D: Performance is a bit lower (close to 10% slower in extreme cases) The benefit for 2D physics to be much more stable outweighs the slight decrease in performance, and this could be alleviated by changing the algorithm to use jacobians for contact solving to help with cache efficiency and memory allocations.
910 lines
28 KiB
C++
910 lines
28 KiB
C++
/*************************************************************************/
|
|
/* godot_body_pair_3d.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 "godot_body_pair_3d.h"
|
|
|
|
#include "godot_collision_solver_3d.h"
|
|
#include "godot_space_3d.h"
|
|
|
|
#include "core/os/os.h"
|
|
|
|
#define MIN_VELOCITY 0.0001
|
|
#define MAX_BIAS_ROTATION (Math_PI / 8)
|
|
|
|
void GodotBodyPair3D::_contact_added_callback(const Vector3 &p_point_A, int p_index_A, const Vector3 &p_point_B, int p_index_B, void *p_userdata) {
|
|
GodotBodyPair3D *pair = (GodotBodyPair3D *)p_userdata;
|
|
pair->contact_added_callback(p_point_A, p_index_A, p_point_B, p_index_B);
|
|
}
|
|
|
|
void GodotBodyPair3D::contact_added_callback(const Vector3 &p_point_A, int p_index_A, const Vector3 &p_point_B, int p_index_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.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.used = true;
|
|
|
|
// 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;
|
|
c = contact;
|
|
return;
|
|
}
|
|
}
|
|
|
|
// 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.
|
|
|
|
const Basis &basis_A = A->get_transform().basis;
|
|
const Basis &basis_B = B->get_transform().basis;
|
|
|
|
int least_deep = -1;
|
|
real_t min_depth;
|
|
|
|
// Start with depth for new contact.
|
|
{
|
|
Vector3 global_A = basis_A.xform(contact.local_A);
|
|
Vector3 global_B = basis_B.xform(contact.local_B) + offset_B;
|
|
|
|
Vector3 axis = global_A - global_B;
|
|
min_depth = axis.dot(contact.normal);
|
|
}
|
|
|
|
for (int i = 0; i < contact_count; i++) {
|
|
const Contact &c = contacts[i];
|
|
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 < min_depth) {
|
|
min_depth = depth;
|
|
least_deep = i;
|
|
}
|
|
}
|
|
|
|
if (least_deep > -1) {
|
|
// Replace the least deep contact by the new one.
|
|
contacts[least_deep] = contact;
|
|
}
|
|
|
|
return;
|
|
}
|
|
|
|
contacts[new_index] = contact;
|
|
contact_count++;
|
|
}
|
|
|
|
void GodotBodyPair3D::validate_contacts() {
|
|
// Make sure to erase contacts that are no longer valid.
|
|
real_t max_separation = space->get_contact_max_separation();
|
|
real_t max_separation2 = max_separation * max_separation;
|
|
|
|
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];
|
|
|
|
bool erase = false;
|
|
if (!c.used) {
|
|
// Was left behind in previous frame.
|
|
erase = true;
|
|
} else {
|
|
c.used = 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 < -max_separation || (global_B + c.normal * depth - global_A).length_squared() > max_separation2) {
|
|
erase = true;
|
|
}
|
|
}
|
|
|
|
if (erase) {
|
|
// 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 GodotBodyPair3D::_test_ccd(real_t p_step, GodotBody3D *p_A, int p_shape_A, const Transform3D &p_xform_A, GodotBody3D *p_B, int p_shape_B, const Transform3D &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;
|
|
|
|
Transform3D 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, true)) {
|
|
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(GodotBody3D *A, GodotBody3D *B) {
|
|
return CLAMP(A->get_bounce() + B->get_bounce(), 0, 1);
|
|
}
|
|
|
|
real_t combine_friction(GodotBody3D *A, GodotBody3D *B) {
|
|
return ABS(MIN(A->get_friction(), B->get_friction()));
|
|
}
|
|
|
|
bool GodotBodyPair3D::setup(real_t p_step) {
|
|
if (!A->interacts_with(B) || A->has_exception(B->get_self()) || B->has_exception(A->get_self())) {
|
|
collided = false;
|
|
return false;
|
|
}
|
|
|
|
collide_A = (A->get_mode() > PhysicsServer3D::BODY_MODE_KINEMATIC) && A->collides_with(B);
|
|
collide_B = (B->get_mode() > PhysicsServer3D::BODY_MODE_KINEMATIC) && B->collides_with(A);
|
|
|
|
report_contacts_only = false;
|
|
if (!collide_A && !collide_B) {
|
|
if ((A->get_max_contacts_reported() > 0) || (B->get_max_contacts_reported() > 0)) {
|
|
report_contacts_only = true;
|
|
} else {
|
|
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();
|
|
Transform3D xform_Au = Transform3D(A->get_transform().basis, Vector3());
|
|
Transform3D xform_A = xform_Au * A->get_shape_transform(shape_A);
|
|
|
|
Transform3D xform_Bu = B->get_transform();
|
|
xform_Bu.origin -= offset_A;
|
|
Transform3D xform_B = xform_Bu * B->get_shape_transform(shape_B);
|
|
|
|
GodotShape3D *shape_A_ptr = A->get_shape(shape_A);
|
|
GodotShape3D *shape_B_ptr = B->get_shape(shape_B);
|
|
|
|
collided = GodotCollisionSolver3D::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() && collide_A) {
|
|
_test_ccd(p_step, A, shape_A, xform_A, B, shape_B, xform_B);
|
|
}
|
|
|
|
if (B->is_continuous_collision_detection_enabled() && collide_B) {
|
|
_test_ccd(p_step, B, shape_B, xform_B, A, shape_A, xform_A);
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
bool GodotBodyPair3D::pre_solve(real_t p_step) {
|
|
if (!collided) {
|
|
return false;
|
|
}
|
|
|
|
real_t max_penetration = space->get_contact_max_allowed_penetration();
|
|
|
|
real_t bias = 0.8;
|
|
|
|
GodotShape3D *shape_A_ptr = A->get_shape(shape_A);
|
|
GodotShape3D *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;
|
|
|
|
Basis zero_basis;
|
|
zero_basis.set_zero();
|
|
|
|
const Basis &inv_inertia_tensor_A = collide_A ? A->get_inv_inertia_tensor() : zero_basis;
|
|
const Basis &inv_inertia_tensor_B = collide_B ? B->get_inv_inertia_tensor() : zero_basis;
|
|
|
|
real_t inv_mass_A = collide_A ? A->get_inv_mass() : 0.0;
|
|
real_t inv_mass_B = collide_B ? B->get_inv_mass() : 0.0;
|
|
|
|
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 <= 0.0) {
|
|
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 = inv_inertia_tensor_A.xform(c.rA.cross(c.normal));
|
|
Vector3 inertia_B = inv_inertia_tensor_B.xform(c.rB.cross(c.normal));
|
|
real_t kNormal = inv_mass_A + inv_mass_B;
|
|
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 (collide_A) {
|
|
A->apply_impulse(-j_vec, c.rA + A->get_center_of_mass());
|
|
}
|
|
if (collide_B) {
|
|
B->apply_impulse(j_vec, c.rB + B->get_center_of_mass());
|
|
}
|
|
|
|
c.bounce = combine_bounce(A, B);
|
|
if (c.bounce) {
|
|
Vector3 crA = A->get_prev_angular_velocity().cross(c.rA);
|
|
Vector3 crB = B->get_prev_angular_velocity().cross(c.rB);
|
|
Vector3 dv = B->get_prev_linear_velocity() + crB - A->get_prev_linear_velocity() - crA;
|
|
c.bounce = c.bounce * dv.dot(c.normal);
|
|
}
|
|
}
|
|
|
|
return do_process;
|
|
}
|
|
|
|
void GodotBodyPair3D::solve(real_t p_step) {
|
|
if (!collided) {
|
|
return;
|
|
}
|
|
|
|
const real_t max_bias_av = MAX_BIAS_ROTATION / p_step;
|
|
|
|
Basis zero_basis;
|
|
zero_basis.set_zero();
|
|
|
|
const Basis &inv_inertia_tensor_A = collide_A ? A->get_inv_inertia_tensor() : zero_basis;
|
|
const Basis &inv_inertia_tensor_B = collide_B ? B->get_inv_inertia_tensor() : zero_basis;
|
|
|
|
real_t inv_mass_A = collide_A ? A->get_inv_mass() : 0.0;
|
|
real_t inv_mass_B = collide_B ? B->get_inv_mass() : 0.0;
|
|
|
|
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 (collide_A) {
|
|
A->apply_bias_impulse(-jb, c.rA + A->get_center_of_mass(), max_bias_av);
|
|
}
|
|
if (collide_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) / (inv_mass_A + inv_mass_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 (collide_A) {
|
|
A->apply_bias_impulse(-jb_com, A->get_center_of_mass(), 0.0f);
|
|
}
|
|
if (collide_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 (collide_A) {
|
|
A->apply_impulse(-j, c.rA + A->get_center_of_mass());
|
|
}
|
|
if (collide_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 = inv_inertia_tensor_A.xform(c.rA.cross(tv));
|
|
Vector3 temp2 = inv_inertia_tensor_B.xform(c.rB.cross(tv));
|
|
|
|
real_t t = -tvl / (inv_mass_A + inv_mass_B + 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 (collide_A) {
|
|
A->apply_impulse(-jt, c.rA + A->get_center_of_mass());
|
|
}
|
|
if (collide_B) {
|
|
B->apply_impulse(jt, c.rB + B->get_center_of_mass());
|
|
}
|
|
|
|
c.active = true;
|
|
}
|
|
}
|
|
}
|
|
|
|
GodotBodyPair3D::GodotBodyPair3D(GodotBody3D *p_A, int p_shape_A, GodotBody3D *p_B, int p_shape_B) :
|
|
GodotBodyContact3D(_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);
|
|
}
|
|
|
|
GodotBodyPair3D::~GodotBodyPair3D() {
|
|
A->remove_constraint(this);
|
|
B->remove_constraint(this);
|
|
}
|
|
|
|
void GodotBodySoftBodyPair3D::_contact_added_callback(const Vector3 &p_point_A, int p_index_A, const Vector3 &p_point_B, int p_index_B, void *p_userdata) {
|
|
GodotBodySoftBodyPair3D *pair = (GodotBodySoftBodyPair3D *)p_userdata;
|
|
pair->contact_added_callback(p_point_A, p_index_A, p_point_B, p_index_B);
|
|
}
|
|
|
|
void GodotBodySoftBodyPair3D::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.local_A = local_A;
|
|
contact.local_B = local_B;
|
|
contact.normal = (p_point_A - p_point_B).normalized();
|
|
contact.used = true;
|
|
|
|
// 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 GodotBodySoftBodyPair3D::validate_contacts() {
|
|
// Make sure to erase contacts that are no longer valid.
|
|
real_t max_separation = space->get_contact_max_separation();
|
|
real_t max_separation2 = max_separation * max_separation;
|
|
|
|
const Transform3D &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];
|
|
|
|
bool erase = false;
|
|
if (!c.used) {
|
|
// Was left behind in previous frame.
|
|
erase = true;
|
|
} else {
|
|
c.used = false;
|
|
|
|
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 < -max_separation || (global_B + c.normal * depth - global_A).length_squared() > max_separation2) {
|
|
erase = true;
|
|
}
|
|
}
|
|
|
|
if (erase) {
|
|
// 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 GodotBodySoftBodyPair3D::setup(real_t p_step) {
|
|
if (!body->interacts_with(soft_body) || body->has_exception(soft_body->get_self()) || soft_body->has_exception(body->get_self())) {
|
|
collided = false;
|
|
return false;
|
|
}
|
|
|
|
body_collides = (body->get_mode() > PhysicsServer3D::BODY_MODE_KINEMATIC) && body->collides_with(soft_body);
|
|
soft_body_collides = soft_body->collides_with(body);
|
|
|
|
if (!body_collides && !soft_body_collides) {
|
|
if (body->get_max_contacts_reported() > 0) {
|
|
report_contacts_only = true;
|
|
} else {
|
|
collided = false;
|
|
return false;
|
|
}
|
|
}
|
|
|
|
const Transform3D &xform_Au = body->get_transform();
|
|
Transform3D xform_A = xform_Au * body->get_shape_transform(body_shape);
|
|
|
|
Transform3D xform_Bu = soft_body->get_transform();
|
|
Transform3D xform_B = xform_Bu * soft_body->get_shape_transform(0);
|
|
|
|
validate_contacts();
|
|
|
|
GodotShape3D *shape_A_ptr = body->get_shape(body_shape);
|
|
GodotShape3D *shape_B_ptr = soft_body->get_shape(0);
|
|
|
|
collided = GodotCollisionSolver3D::solve_static(shape_A_ptr, xform_A, shape_B_ptr, xform_B, _contact_added_callback, this, &sep_axis);
|
|
|
|
return collided;
|
|
}
|
|
|
|
bool GodotBodySoftBodyPair3D::pre_solve(real_t p_step) {
|
|
if (!collided) {
|
|
return false;
|
|
}
|
|
|
|
real_t max_penetration = space->get_contact_max_allowed_penetration();
|
|
|
|
real_t bias = 0.8;
|
|
|
|
GodotShape3D *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 Transform3D &transform_A = body->get_transform();
|
|
|
|
Basis zero_basis;
|
|
zero_basis.set_zero();
|
|
|
|
const Basis &body_inv_inertia_tensor = body_collides ? body->get_inv_inertia_tensor() : zero_basis;
|
|
|
|
real_t body_inv_mass = body_collides ? body->get_inv_mass() : 0.0;
|
|
|
|
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_collides ? soft_body->get_node_inv_mass(c.index_B) : 0.0;
|
|
if ((node_inv_mass == 0.0) && (body_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 <= 0.0) {
|
|
continue;
|
|
}
|
|
|
|
#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 (report_contacts_only) {
|
|
collided = false;
|
|
continue;
|
|
}
|
|
|
|
c.active = true;
|
|
do_process = true;
|
|
|
|
if (body_collides) {
|
|
body->set_active(true);
|
|
}
|
|
|
|
// Precompute normal mass, tangent mass, and bias.
|
|
Vector3 inertia_A = body_inv_inertia_tensor.xform(c.rA.cross(c.normal));
|
|
real_t kNormal = body_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_collides) {
|
|
body->apply_impulse(-j_vec, c.rA + body->get_center_of_mass());
|
|
}
|
|
if (soft_body_collides) {
|
|
soft_body->apply_node_impulse(c.index_B, j_vec);
|
|
}
|
|
|
|
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 GodotBodySoftBodyPair3D::solve(real_t p_step) {
|
|
if (!collided) {
|
|
return;
|
|
}
|
|
|
|
const real_t max_bias_av = MAX_BIAS_ROTATION / p_step;
|
|
|
|
Basis zero_basis;
|
|
zero_basis.set_zero();
|
|
|
|
const Basis &body_inv_inertia_tensor = body_collides ? body->get_inv_inertia_tensor() : zero_basis;
|
|
|
|
real_t body_inv_mass = body_collides ? body->get_inv_mass() : 0.0;
|
|
|
|
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;
|
|
|
|
real_t node_inv_mass = soft_body_collides ? soft_body->get_node_inv_mass(c.index_B) : 0.0;
|
|
|
|
// 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_collides) {
|
|
body->apply_bias_impulse(-jb, c.rA + body->get_center_of_mass(), max_bias_av);
|
|
}
|
|
if (soft_body_collides) {
|
|
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_inv_mass + node_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 (body_collides) {
|
|
body->apply_bias_impulse(-jb_com, body->get_center_of_mass(), 0.0f);
|
|
}
|
|
if (soft_body_collides) {
|
|
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_collides) {
|
|
body->apply_impulse(-j, c.rA + body->get_center_of_mass());
|
|
}
|
|
if (soft_body_collides) {
|
|
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_inv_inertia_tensor.xform(c.rA.cross(tv));
|
|
|
|
real_t t = -tvl / (body_inv_mass + node_inv_mass + 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_collides) {
|
|
body->apply_impulse(-jt, c.rA + body->get_center_of_mass());
|
|
}
|
|
if (soft_body_collides) {
|
|
soft_body->apply_node_impulse(c.index_B, jt);
|
|
}
|
|
|
|
c.active = true;
|
|
}
|
|
}
|
|
}
|
|
|
|
GodotBodySoftBodyPair3D::GodotBodySoftBodyPair3D(GodotBody3D *p_A, int p_shape_A, GodotSoftBody3D *p_B) :
|
|
GodotBodyContact3D(&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);
|
|
}
|
|
|
|
GodotBodySoftBodyPair3D::~GodotBodySoftBodyPair3D() {
|
|
body->remove_constraint(this);
|
|
soft_body->remove_constraint(this);
|
|
}
|