2290f3b6a4
For example, an axis-aligned box under the influence of gravity landing on a horizontal triangle could previously tunnel, because only one of the supports of the box was considered to be the candidate point that would collide first. Now all supports are considered as candidates. Also fix CCD always pushing the fast body into the other body, which works well for convex shapes but not for trimesh/concave shapes.
988 lines
31 KiB
C++
988 lines
31 KiB
C++
/**************************************************************************/
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/* godot_body_pair_3d.cpp */
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/**************************************************************************/
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/* This file is part of: */
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/* GODOT ENGINE */
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/* https://godotengine.org */
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/**************************************************************************/
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/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */
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/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur. */
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/* */
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/* Permission is hereby granted, free of charge, to any person obtaining */
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/* a copy of this software and associated documentation files (the */
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/* "Software"), to deal in the Software without restriction, including */
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/* without limitation the rights to use, copy, modify, merge, publish, */
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/* distribute, sublicense, and/or sell copies of the Software, and to */
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/* permit persons to whom the Software is furnished to do so, subject to */
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/* the following conditions: */
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/* */
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/* The above copyright notice and this permission notice shall be */
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/* included in all copies or substantial portions of the Software. */
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/* */
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/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
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/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
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/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */
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/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
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/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
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/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
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/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
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/**************************************************************************/
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#include "godot_body_pair_3d.h"
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#include "godot_collision_solver_3d.h"
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#include "godot_space_3d.h"
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#include "core/os/os.h"
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#define MIN_VELOCITY 0.0001
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#define MAX_BIAS_ROTATION (Math_PI / 8)
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void GodotBodyPair3D::_contact_added_callback(const Vector3 &p_point_A, int p_index_A, const Vector3 &p_point_B, int p_index_B, const Vector3 &normal, void *p_userdata) {
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GodotBodyPair3D *pair = static_cast<GodotBodyPair3D *>(p_userdata);
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pair->contact_added_callback(p_point_A, p_index_A, p_point_B, p_index_B, normal);
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}
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void GodotBodyPair3D::contact_added_callback(const Vector3 &p_point_A, int p_index_A, const Vector3 &p_point_B, int p_index_B, const Vector3 &normal) {
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Vector3 local_A = A->get_inv_transform().basis.xform(p_point_A);
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Vector3 local_B = B->get_inv_transform().basis.xform(p_point_B - offset_B);
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int new_index = contact_count;
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ERR_FAIL_COND(new_index >= (MAX_CONTACTS + 1));
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Contact contact;
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contact.index_A = p_index_A;
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contact.index_B = p_index_B;
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contact.local_A = local_A;
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contact.local_B = local_B;
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contact.normal = (p_point_A - p_point_B).normalized();
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contact.used = true;
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// Attempt to determine if the contact will be reused.
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real_t contact_recycle_radius = space->get_contact_recycle_radius();
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for (int i = 0; i < contact_count; i++) {
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Contact &c = contacts[i];
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if (c.local_A.distance_squared_to(local_A) < (contact_recycle_radius * contact_recycle_radius) &&
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c.local_B.distance_squared_to(local_B) < (contact_recycle_radius * contact_recycle_radius)) {
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contact.acc_normal_impulse = c.acc_normal_impulse;
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contact.acc_bias_impulse = c.acc_bias_impulse;
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contact.acc_bias_impulse_center_of_mass = c.acc_bias_impulse_center_of_mass;
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contact.acc_tangent_impulse = c.acc_tangent_impulse;
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c = contact;
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return;
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}
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}
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// Figure out if the contact amount must be reduced to fit the new contact.
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if (new_index == MAX_CONTACTS) {
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// Remove the contact with the minimum depth.
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const Basis &basis_A = A->get_transform().basis;
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const Basis &basis_B = B->get_transform().basis;
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int least_deep = -1;
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real_t min_depth;
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// Start with depth for new contact.
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{
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Vector3 global_A = basis_A.xform(contact.local_A);
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Vector3 global_B = basis_B.xform(contact.local_B) + offset_B;
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Vector3 axis = global_A - global_B;
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min_depth = axis.dot(contact.normal);
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}
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for (int i = 0; i < contact_count; i++) {
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const Contact &c = contacts[i];
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Vector3 global_A = basis_A.xform(c.local_A);
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Vector3 global_B = basis_B.xform(c.local_B) + offset_B;
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Vector3 axis = global_A - global_B;
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real_t depth = axis.dot(c.normal);
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if (depth < min_depth) {
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min_depth = depth;
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least_deep = i;
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}
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}
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if (least_deep > -1) {
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// Replace the least deep contact by the new one.
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contacts[least_deep] = contact;
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}
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return;
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}
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contacts[new_index] = contact;
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contact_count++;
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}
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void GodotBodyPair3D::validate_contacts() {
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// Make sure to erase contacts that are no longer valid.
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real_t max_separation = space->get_contact_max_separation();
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real_t max_separation2 = max_separation * max_separation;
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const Basis &basis_A = A->get_transform().basis;
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const Basis &basis_B = B->get_transform().basis;
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for (int i = 0; i < contact_count; i++) {
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Contact &c = contacts[i];
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bool erase = false;
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if (!c.used) {
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// Was left behind in previous frame.
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erase = true;
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} else {
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c.used = false;
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Vector3 global_A = basis_A.xform(c.local_A);
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Vector3 global_B = basis_B.xform(c.local_B) + offset_B;
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Vector3 axis = global_A - global_B;
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real_t depth = axis.dot(c.normal);
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if (depth < -max_separation || (global_B + c.normal * depth - global_A).length_squared() > max_separation2) {
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erase = true;
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}
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}
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if (erase) {
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// Contact no longer needed, remove.
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if ((i + 1) < contact_count) {
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// Swap with the last one.
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SWAP(contacts[i], contacts[contact_count - 1]);
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}
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i--;
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contact_count--;
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}
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}
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}
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// _test_ccd prevents tunneling by slowing down a high velocity body that is about to collide so that next frame it will be at an appropriate location to collide (i.e. slight overlap)
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// Warning: the way velocity is adjusted down to cause a collision means the momentum will be weaker than it should for a bounce!
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// Process: only proceed if body A's motion is high relative to its size.
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// cast forward along motion vector to see if A is going to enter/pass B's collider next frame, only proceed if it does.
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// adjust the velocity of A down so that it will just slightly intersect the collider instead of blowing right past it.
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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) {
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GodotShape3D *shape_A_ptr = p_A->get_shape(p_shape_A);
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GodotShape3D *shape_B_ptr = p_B->get_shape(p_shape_B);
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Vector3 motion = p_A->get_linear_velocity() * p_step;
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real_t mlen = motion.length();
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if (mlen < CMP_EPSILON) {
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return false;
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}
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Vector3 mnormal = motion / mlen;
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real_t min = 0.0, max = 0.0;
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shape_A_ptr->project_range(mnormal, p_xform_A, min, max);
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// Did it move enough in this direction to even attempt raycast?
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// Let's say it should move more than 1/3 the size of the object in that axis.
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bool fast_object = mlen > (max - min) * 0.3;
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if (!fast_object) {
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return false; // moving slow enough that there's no chance of tunneling.
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}
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// A is moving fast enough that tunneling might occur. See if it's really about to collide.
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// Support points are the farthest forward points on A in the direction of the motion vector.
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// i.e. the candidate points of which one should hit B first if any collision does occur.
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static const int max_supports = 16;
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Vector3 supports_A[max_supports];
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int support_count_A;
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GodotShape3D::FeatureType support_type_A;
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// Convert mnormal into body A's local xform because get_supports requires (and returns) local coordinates.
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shape_A_ptr->get_supports(p_xform_A.basis.xform_inv(mnormal).normalized(), max_supports, supports_A, support_count_A, support_type_A);
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// Cast a segment from each support point of A in the motion direction.
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int segment_support_idx = -1;
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float segment_hit_length = FLT_MAX;
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Vector3 segment_hit_local;
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for (int i = 0; i < support_count_A; i++) {
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supports_A[i] = p_xform_A.xform(supports_A[i]);
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Vector3 from = supports_A[i];
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Vector3 to = from + motion;
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Transform3D from_inv = p_xform_B.affine_inverse();
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// Back up 10% of the per-frame motion behind the support point and use that as the beginning of our cast.
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// At high speeds, this may mean we're actually casting from well behind the body instead of inside it, which is odd.
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// But it still works out.
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Vector3 local_from = from_inv.xform(from - motion * 0.1);
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Vector3 local_to = from_inv.xform(to);
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Vector3 rpos, rnorm;
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if (shape_B_ptr->intersect_segment(local_from, local_to, rpos, rnorm, true)) {
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float hit_length = local_from.distance_to(rpos);
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if (hit_length < segment_hit_length) {
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segment_support_idx = i;
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segment_hit_length = hit_length;
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segment_hit_local = rpos;
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}
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}
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}
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if (segment_support_idx == -1) {
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// There was no hit. Since the segment is the length of per-frame motion, this means the bodies will not
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// actually collide yet on next frame. We'll probably check again next frame once they're closer.
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return false;
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}
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Vector3 hitpos = p_xform_B.xform(segment_hit_local);
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real_t newlen = hitpos.distance_to(supports_A[segment_support_idx]);
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if (shape_B_ptr->is_concave()) {
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// Subtracting 5% of body length from the distance between collision and support point
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// should cause body A's support point to arrive just before a face of B next frame.
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newlen = MAX(newlen - (max - min) * 0.05, 0.0);
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// NOTE: This may stop body A completely, without a proper collision response.
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// We consider this preferable to tunneling.
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} else {
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// Adding 1% of body length to the distance between collision and support point
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// should cause body A's support point to arrive just within B's collider next frame.
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newlen += (max - min) * 0.01;
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}
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p_A->set_linear_velocity((mnormal * newlen) / p_step);
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return true;
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}
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real_t combine_bounce(GodotBody3D *A, GodotBody3D *B) {
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return CLAMP(A->get_bounce() + B->get_bounce(), 0, 1);
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}
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real_t combine_friction(GodotBody3D *A, GodotBody3D *B) {
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return ABS(MIN(A->get_friction(), B->get_friction()));
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}
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bool GodotBodyPair3D::setup(real_t p_step) {
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check_ccd = false;
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if (!A->interacts_with(B) || A->has_exception(B->get_self()) || B->has_exception(A->get_self())) {
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collided = false;
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return false;
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}
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collide_A = (A->get_mode() > PhysicsServer3D::BODY_MODE_KINEMATIC) && A->collides_with(B);
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collide_B = (B->get_mode() > PhysicsServer3D::BODY_MODE_KINEMATIC) && B->collides_with(A);
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report_contacts_only = false;
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if (!collide_A && !collide_B) {
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if ((A->get_max_contacts_reported() > 0) || (B->get_max_contacts_reported() > 0)) {
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report_contacts_only = true;
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} else {
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collided = false;
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return false;
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}
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}
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offset_B = B->get_transform().get_origin() - A->get_transform().get_origin();
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validate_contacts();
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const Vector3 &offset_A = A->get_transform().get_origin();
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Transform3D xform_Au = Transform3D(A->get_transform().basis, Vector3());
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Transform3D xform_A = xform_Au * A->get_shape_transform(shape_A);
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Transform3D xform_Bu = B->get_transform();
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xform_Bu.origin -= offset_A;
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Transform3D xform_B = xform_Bu * B->get_shape_transform(shape_B);
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GodotShape3D *shape_A_ptr = A->get_shape(shape_A);
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GodotShape3D *shape_B_ptr = B->get_shape(shape_B);
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collided = GodotCollisionSolver3D::solve_static(shape_A_ptr, xform_A, shape_B_ptr, xform_B, _contact_added_callback, this, &sep_axis);
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if (!collided) {
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if (A->is_continuous_collision_detection_enabled() && collide_A) {
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check_ccd = true;
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return true;
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}
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if (B->is_continuous_collision_detection_enabled() && collide_B) {
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check_ccd = true;
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return true;
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}
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return false;
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}
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return true;
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}
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bool GodotBodyPair3D::pre_solve(real_t p_step) {
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if (!collided) {
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if (check_ccd) {
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const Vector3 &offset_A = A->get_transform().get_origin();
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Transform3D xform_Au = Transform3D(A->get_transform().basis, Vector3());
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Transform3D xform_A = xform_Au * A->get_shape_transform(shape_A);
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Transform3D xform_Bu = B->get_transform();
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xform_Bu.origin -= offset_A;
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Transform3D xform_B = xform_Bu * B->get_shape_transform(shape_B);
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if (A->is_continuous_collision_detection_enabled() && collide_A) {
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_test_ccd(p_step, A, shape_A, xform_A, B, shape_B, xform_B);
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}
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if (B->is_continuous_collision_detection_enabled() && collide_B) {
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_test_ccd(p_step, B, shape_B, xform_B, A, shape_A, xform_A);
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}
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}
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return false;
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}
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real_t max_penetration = space->get_contact_max_allowed_penetration();
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real_t bias = 0.8;
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GodotShape3D *shape_A_ptr = A->get_shape(shape_A);
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GodotShape3D *shape_B_ptr = B->get_shape(shape_B);
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if (shape_A_ptr->get_custom_bias() || shape_B_ptr->get_custom_bias()) {
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if (shape_A_ptr->get_custom_bias() == 0) {
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bias = shape_B_ptr->get_custom_bias();
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} else if (shape_B_ptr->get_custom_bias() == 0) {
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bias = shape_A_ptr->get_custom_bias();
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} else {
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bias = (shape_B_ptr->get_custom_bias() + shape_A_ptr->get_custom_bias()) * 0.5;
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}
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}
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real_t inv_dt = 1.0 / p_step;
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bool do_process = false;
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const Basis &basis_A = A->get_transform().basis;
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const Basis &basis_B = B->get_transform().basis;
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Basis zero_basis;
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zero_basis.set_zero();
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const Basis &inv_inertia_tensor_A = collide_A ? A->get_inv_inertia_tensor() : zero_basis;
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const Basis &inv_inertia_tensor_B = collide_B ? B->get_inv_inertia_tensor() : zero_basis;
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real_t inv_mass_A = collide_A ? A->get_inv_mass() : 0.0;
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real_t inv_mass_B = collide_B ? B->get_inv_mass() : 0.0;
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for (int i = 0; i < contact_count; i++) {
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Contact &c = contacts[i];
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c.active = false;
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Vector3 global_A = basis_A.xform(c.local_A);
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Vector3 global_B = basis_B.xform(c.local_B) + offset_B;
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Vector3 axis = global_A - global_B;
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real_t depth = axis.dot(c.normal);
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if (depth <= 0.0) {
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continue;
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}
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#ifdef DEBUG_ENABLED
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if (space->is_debugging_contacts()) {
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const Vector3 &offset_A = A->get_transform().get_origin();
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space->add_debug_contact(global_A + offset_A);
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space->add_debug_contact(global_B + offset_A);
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}
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#endif
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c.rA = global_A - A->get_center_of_mass();
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c.rB = global_B - B->get_center_of_mass() - offset_B;
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// Precompute normal mass, tangent mass, and bias.
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Vector3 inertia_A = inv_inertia_tensor_A.xform(c.rA.cross(c.normal));
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Vector3 inertia_B = inv_inertia_tensor_B.xform(c.rB.cross(c.normal));
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real_t kNormal = inv_mass_A + inv_mass_B;
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kNormal += c.normal.dot(inertia_A.cross(c.rA)) + c.normal.dot(inertia_B.cross(c.rB));
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c.mass_normal = 1.0f / kNormal;
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c.bias = -bias * inv_dt * MIN(0.0f, -depth + max_penetration);
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c.depth = depth;
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Vector3 j_vec = c.normal * c.acc_normal_impulse + c.acc_tangent_impulse;
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c.acc_impulse -= j_vec;
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// contact query reporting...
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if (A->can_report_contacts()) {
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Vector3 crA = A->get_angular_velocity().cross(c.rA) + A->get_linear_velocity();
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A->add_contact(global_A, -c.normal, depth, shape_A, global_B, shape_B, B->get_instance_id(), B->get_self(), crA, c.acc_impulse);
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}
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if (B->can_report_contacts()) {
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Vector3 crB = B->get_angular_velocity().cross(c.rB) + B->get_linear_velocity();
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B->add_contact(global_B, c.normal, depth, shape_B, global_A, shape_A, A->get_instance_id(), A->get_self(), crB, -c.acc_impulse);
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}
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if (report_contacts_only) {
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collided = false;
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continue;
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}
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|
|
c.active = true;
|
|
do_process = true;
|
|
|
|
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.acc_impulse -= j;
|
|
|
|
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.acc_impulse -= jt;
|
|
|
|
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, const Vector3 &normal, void *p_userdata) {
|
|
GodotBodySoftBodyPair3D *pair = static_cast<GodotBodySoftBodyPair3D *>(p_userdata);
|
|
pair->contact_added_callback(p_point_A, p_index_A, p_point_B, p_index_B, normal);
|
|
}
|
|
|
|
void GodotBodySoftBodyPair3D::contact_added_callback(const Vector3 &p_point_A, int p_index_A, const Vector3 &p_point_B, int p_index_B, const Vector3 &normal) {
|
|
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 = (normal.dot((p_point_A - p_point_B)) < 0 ? -normal : normal);
|
|
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 = space->get_contact_bias();
|
|
|
|
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;
|
|
|
|
// 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.acc_impulse -= j_vec;
|
|
|
|
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, c.acc_impulse);
|
|
}
|
|
|
|
if (report_contacts_only) {
|
|
collided = false;
|
|
continue;
|
|
}
|
|
|
|
c.active = true;
|
|
do_process = true;
|
|
|
|
if (body_collides) {
|
|
body->set_active(true);
|
|
}
|
|
|
|
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.acc_impulse -= 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.acc_impulse -= 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);
|
|
}
|