989 lines
31 KiB
C++
989 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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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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// Roughly predict body B's position in the next frame (ignoring collisions).
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Transform3D predicted_xform_B = p_xform_B.translated(p_B->get_linear_velocity() * p_step);
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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 = predicted_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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int fi = -1;
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if (p_B->get_shape(p_shape_B)->intersect_segment(local_from, local_to, rpos, rnorm, fi, 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 = predicted_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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// 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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// FIXME: This doesn't always work well when colliding with a triangle face of a trimesh shape.
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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 Vector3 &offset_A = A->get_transform().get_origin();
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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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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() || 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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Vector3 crA = A->get_angular_velocity().cross(c.rA) + A->get_linear_velocity();
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if (A->can_report_contacts()) {
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A->add_contact(global_A + offset_A, -c.normal, depth, shape_A, crA, global_B + offset_A, shape_B, B->get_instance_id(), B->get_self(), crB, c.acc_impulse);
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}
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if (B->can_report_contacts()) {
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B->add_contact(global_B + offset_A, c.normal, depth, shape_B, crB, global_A + offset_A, shape_A, A->get_instance_id(), A->get_self(), crA, -c.acc_impulse);
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}
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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;
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do_process = true;
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if (collide_A) {
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A->apply_impulse(-j_vec, c.rA + A->get_center_of_mass());
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}
|
|
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();
|
|
Vector3 crB = soft_body->get_node_velocity(c.index_B);
|
|
body->add_contact(global_A, -c.normal, depth, body_shape, crA, global_B, 0, soft_body->get_instance_id(), soft_body->get_self(), crB, 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);
|
|
}
|