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Diffstat (limited to 'modules/godot_physics_3d/godot_body_pair_3d.cpp')
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diff --git a/modules/godot_physics_3d/godot_body_pair_3d.cpp b/modules/godot_physics_3d/godot_body_pair_3d.cpp new file mode 100644 index 0000000000..84fae73616 --- /dev/null +++ b/modules/godot_physics_3d/godot_body_pair_3d.cpp @@ -0,0 +1,988 @@ +/**************************************************************************/ +/* godot_body_pair_3d.cpp */ +/**************************************************************************/ +/* This file is part of: */ +/* GODOT ENGINE */ +/* https://godotengine.org */ +/**************************************************************************/ +/* Copyright (c) 2014-present Godot Engine contributors (see AUTHORS.md). */ +/* Copyright (c) 2007-2014 Juan Linietsky, Ariel Manzur. */ +/* */ +/* Permission is hereby granted, free of charge, to any person obtaining */ +/* a copy of this software and associated documentation files (the */ +/* "Software"), to deal in the Software without restriction, including */ +/* without limitation the rights to use, copy, modify, merge, publish, */ +/* distribute, sublicense, and/or sell copies of the Software, and to */ +/* permit persons to whom the Software is furnished to do so, subject to */ +/* the following conditions: */ +/* */ +/* The above copyright notice and this permission notice shall be */ +/* included in all copies or substantial portions of the Software. */ +/* */ +/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */ +/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */ +/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. */ +/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */ +/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */ +/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */ +/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */ +/**************************************************************************/ + +#include "godot_body_pair_3d.h" + +#include "godot_collision_solver_3d.h" +#include "godot_space_3d.h" + +#include "core/os/os.h" + +#define MIN_VELOCITY 0.0001 +#define MAX_BIAS_ROTATION (Math_PI / 8) + +void GodotBodyPair3D::_contact_added_callback(const Vector3 &p_point_A, int p_index_A, const Vector3 &p_point_B, int p_index_B, const Vector3 &normal, void *p_userdata) { + GodotBodyPair3D *pair = static_cast<GodotBodyPair3D *>(p_userdata); + pair->contact_added_callback(p_point_A, p_index_A, p_point_B, p_index_B, normal); +} + +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) { + Vector3 local_A = A->get_inv_transform().basis.xform(p_point_A); + Vector3 local_B = B->get_inv_transform().basis.xform(p_point_B - offset_B); + + int new_index = contact_count; + + ERR_FAIL_COND(new_index >= (MAX_CONTACTS + 1)); + + Contact contact; + contact.index_A = p_index_A; + contact.index_B = p_index_B; + contact.local_A = local_A; + contact.local_B = local_B; + contact.normal = (p_point_A - p_point_B).normalized(); + contact.used = true; + + // Attempt to determine if the contact will be reused. + real_t contact_recycle_radius = space->get_contact_recycle_radius(); + + for (int i = 0; i < contact_count; i++) { + Contact &c = contacts[i]; + if (c.local_A.distance_squared_to(local_A) < (contact_recycle_radius * contact_recycle_radius) && + c.local_B.distance_squared_to(local_B) < (contact_recycle_radius * contact_recycle_radius)) { + contact.acc_normal_impulse = c.acc_normal_impulse; + contact.acc_bias_impulse = c.acc_bias_impulse; + contact.acc_bias_impulse_center_of_mass = c.acc_bias_impulse_center_of_mass; + contact.acc_tangent_impulse = c.acc_tangent_impulse; + c = contact; + return; + } + } + + // Figure out if the contact amount must be reduced to fit the new contact. + if (new_index == MAX_CONTACTS) { + // Remove the contact with the minimum depth. + + const Basis &basis_A = A->get_transform().basis; + const Basis &basis_B = B->get_transform().basis; + + int least_deep = -1; + real_t min_depth; + + // Start with depth for new contact. + { + Vector3 global_A = basis_A.xform(contact.local_A); + Vector3 global_B = basis_B.xform(contact.local_B) + offset_B; + + Vector3 axis = global_A - global_B; + min_depth = axis.dot(contact.normal); + } + + for (int i = 0; i < contact_count; i++) { + const Contact &c = contacts[i]; + Vector3 global_A = basis_A.xform(c.local_A); + Vector3 global_B = basis_B.xform(c.local_B) + offset_B; + + Vector3 axis = global_A - global_B; + real_t depth = axis.dot(c.normal); + + if (depth < min_depth) { + min_depth = depth; + least_deep = i; + } + } + + if (least_deep > -1) { + // Replace the least deep contact by the new one. + contacts[least_deep] = contact; + } + + return; + } + + contacts[new_index] = contact; + contact_count++; +} + +void GodotBodyPair3D::validate_contacts() { + // Make sure to erase contacts that are no longer valid. + real_t max_separation = space->get_contact_max_separation(); + real_t max_separation2 = max_separation * max_separation; + + const Basis &basis_A = A->get_transform().basis; + const Basis &basis_B = B->get_transform().basis; + + for (int i = 0; i < contact_count; i++) { + Contact &c = contacts[i]; + + bool erase = false; + if (!c.used) { + // Was left behind in previous frame. + erase = true; + } else { + c.used = false; + + Vector3 global_A = basis_A.xform(c.local_A); + Vector3 global_B = basis_B.xform(c.local_B) + offset_B; + Vector3 axis = global_A - global_B; + real_t depth = axis.dot(c.normal); + + if (depth < -max_separation || (global_B + c.normal * depth - global_A).length_squared() > max_separation2) { + erase = true; + } + } + + if (erase) { + // Contact no longer needed, remove. + if ((i + 1) < contact_count) { + // Swap with the last one. + SWAP(contacts[i], contacts[contact_count - 1]); + } + + i--; + contact_count--; + } + } +} + +// _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) +// Warning: the way velocity is adjusted down to cause a collision means the momentum will be weaker than it should for a bounce! +// Process: only proceed if body A's motion is high relative to its size. +// cast forward along motion vector to see if A is going to enter/pass B's collider next frame, only proceed if it does. +// adjust the velocity of A down so that it will just slightly intersect the collider instead of blowing right past it. +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) { + GodotShape3D *shape_A_ptr = p_A->get_shape(p_shape_A); + + Vector3 motion = p_A->get_linear_velocity() * p_step; + real_t mlen = motion.length(); + if (mlen < CMP_EPSILON) { + return false; + } + + Vector3 mnormal = motion / mlen; + + real_t min = 0.0, max = 0.0; + shape_A_ptr->project_range(mnormal, p_xform_A, min, max); + + // Did it move enough in this direction to even attempt raycast? + // Let's say it should move more than 1/3 the size of the object in that axis. + bool fast_object = mlen > (max - min) * 0.3; + if (!fast_object) { + return false; // moving slow enough that there's no chance of tunneling. + } + + // A is moving fast enough that tunneling might occur. See if it's really about to collide. + + // Roughly predict body B's position in the next frame (ignoring collisions). + Transform3D predicted_xform_B = p_xform_B.translated(p_B->get_linear_velocity() * p_step); + + // Support points are the farthest forward points on A in the direction of the motion vector. + // i.e. the candidate points of which one should hit B first if any collision does occur. + static const int max_supports = 16; + Vector3 supports_A[max_supports]; + int support_count_A; + GodotShape3D::FeatureType support_type_A; + // Convert mnormal into body A's local xform because get_supports requires (and returns) local coordinates. + shape_A_ptr->get_supports(p_xform_A.basis.xform_inv(mnormal).normalized(), max_supports, supports_A, support_count_A, support_type_A); + + // Cast a segment from each support point of A in the motion direction. + int segment_support_idx = -1; + float segment_hit_length = FLT_MAX; + Vector3 segment_hit_local; + for (int i = 0; i < support_count_A; i++) { + supports_A[i] = p_xform_A.xform(supports_A[i]); + + Vector3 from = supports_A[i]; + Vector3 to = from + motion; + + Transform3D from_inv = predicted_xform_B.affine_inverse(); + + // Back up 10% of the per-frame motion behind the support point and use that as the beginning of our cast. + // At high speeds, this may mean we're actually casting from well behind the body instead of inside it, which is odd. + // But it still works out. + Vector3 local_from = from_inv.xform(from - motion * 0.1); + Vector3 local_to = from_inv.xform(to); + + Vector3 rpos, rnorm; + int fi = -1; + if (p_B->get_shape(p_shape_B)->intersect_segment(local_from, local_to, rpos, rnorm, fi, true)) { + float hit_length = local_from.distance_to(rpos); + if (hit_length < segment_hit_length) { + segment_support_idx = i; + segment_hit_length = hit_length; + segment_hit_local = rpos; + } + } + } + + if (segment_support_idx == -1) { + // There was no hit. Since the segment is the length of per-frame motion, this means the bodies will not + // actually collide yet on next frame. We'll probably check again next frame once they're closer. + return false; + } + + Vector3 hitpos = predicted_xform_B.xform(segment_hit_local); + + real_t newlen = hitpos.distance_to(supports_A[segment_support_idx]); + // Adding 1% of body length to the distance between collision and support point + // should cause body A's support point to arrive just within B's collider next frame. + newlen += (max - min) * 0.01; + // FIXME: This doesn't always work well when colliding with a triangle face of a trimesh shape. + + p_A->set_linear_velocity((mnormal * newlen) / p_step); + + return true; +} + +real_t combine_bounce(GodotBody3D *A, GodotBody3D *B) { + return CLAMP(A->get_bounce() + B->get_bounce(), 0, 1); +} + +real_t combine_friction(GodotBody3D *A, GodotBody3D *B) { + return ABS(MIN(A->get_friction(), B->get_friction())); +} + +bool GodotBodyPair3D::setup(real_t p_step) { + check_ccd = false; + + if (!A->interacts_with(B) || A->has_exception(B->get_self()) || B->has_exception(A->get_self())) { + collided = false; + return false; + } + + collide_A = (A->get_mode() > PhysicsServer3D::BODY_MODE_KINEMATIC) && A->collides_with(B); + collide_B = (B->get_mode() > PhysicsServer3D::BODY_MODE_KINEMATIC) && B->collides_with(A); + + report_contacts_only = false; + if (!collide_A && !collide_B) { + if ((A->get_max_contacts_reported() > 0) || (B->get_max_contacts_reported() > 0)) { + report_contacts_only = true; + } else { + collided = false; + return false; + } + } + + offset_B = B->get_transform().get_origin() - A->get_transform().get_origin(); + + validate_contacts(); + + const Vector3 &offset_A = A->get_transform().get_origin(); + Transform3D xform_Au = Transform3D(A->get_transform().basis, Vector3()); + Transform3D xform_A = xform_Au * A->get_shape_transform(shape_A); + + Transform3D xform_Bu = B->get_transform(); + xform_Bu.origin -= offset_A; + Transform3D xform_B = xform_Bu * B->get_shape_transform(shape_B); + + GodotShape3D *shape_A_ptr = A->get_shape(shape_A); + GodotShape3D *shape_B_ptr = B->get_shape(shape_B); + + collided = GodotCollisionSolver3D::solve_static(shape_A_ptr, xform_A, shape_B_ptr, xform_B, _contact_added_callback, this, &sep_axis); + + if (!collided) { + if (A->is_continuous_collision_detection_enabled() && collide_A) { + check_ccd = true; + return true; + } + + if (B->is_continuous_collision_detection_enabled() && collide_B) { + check_ccd = true; + return true; + } + + return false; + } + + return true; +} + +bool GodotBodyPair3D::pre_solve(real_t p_step) { + if (!collided) { + if (check_ccd) { + const Vector3 &offset_A = A->get_transform().get_origin(); + Transform3D xform_Au = Transform3D(A->get_transform().basis, Vector3()); + Transform3D xform_A = xform_Au * A->get_shape_transform(shape_A); + + Transform3D xform_Bu = B->get_transform(); + xform_Bu.origin -= offset_A; + Transform3D xform_B = xform_Bu * B->get_shape_transform(shape_B); + + if (A->is_continuous_collision_detection_enabled() && collide_A) { + _test_ccd(p_step, A, shape_A, xform_A, B, shape_B, xform_B); + } + + if (B->is_continuous_collision_detection_enabled() && collide_B) { + _test_ccd(p_step, B, shape_B, xform_B, A, shape_A, xform_A); + } + } + + return false; + } + + real_t max_penetration = space->get_contact_max_allowed_penetration(); + + real_t bias = 0.8; + + GodotShape3D *shape_A_ptr = A->get_shape(shape_A); + GodotShape3D *shape_B_ptr = B->get_shape(shape_B); + + if (shape_A_ptr->get_custom_bias() || shape_B_ptr->get_custom_bias()) { + if (shape_A_ptr->get_custom_bias() == 0) { + bias = shape_B_ptr->get_custom_bias(); + } else if (shape_B_ptr->get_custom_bias() == 0) { + bias = shape_A_ptr->get_custom_bias(); + } else { + bias = (shape_B_ptr->get_custom_bias() + shape_A_ptr->get_custom_bias()) * 0.5; + } + } + + real_t inv_dt = 1.0 / p_step; + + bool do_process = false; + + const Vector3 &offset_A = A->get_transform().get_origin(); + + const Basis &basis_A = A->get_transform().basis; + const Basis &basis_B = B->get_transform().basis; + + Basis zero_basis; + zero_basis.set_zero(); + + const Basis &inv_inertia_tensor_A = collide_A ? A->get_inv_inertia_tensor() : zero_basis; + const Basis &inv_inertia_tensor_B = collide_B ? B->get_inv_inertia_tensor() : zero_basis; + + real_t inv_mass_A = collide_A ? A->get_inv_mass() : 0.0; + real_t inv_mass_B = collide_B ? B->get_inv_mass() : 0.0; + + for (int i = 0; i < contact_count; i++) { + Contact &c = contacts[i]; + c.active = false; + + Vector3 global_A = basis_A.xform(c.local_A); + Vector3 global_B = basis_B.xform(c.local_B) + offset_B; + + Vector3 axis = global_A - global_B; + real_t depth = axis.dot(c.normal); + + if (depth <= 0.0) { + continue; + } + +#ifdef DEBUG_ENABLED + if (space->is_debugging_contacts()) { + space->add_debug_contact(global_A + offset_A); + space->add_debug_contact(global_B + offset_A); + } +#endif + + c.rA = global_A - A->get_center_of_mass(); + c.rB = global_B - B->get_center_of_mass() - offset_B; + + // Precompute normal mass, tangent mass, and bias. + Vector3 inertia_A = inv_inertia_tensor_A.xform(c.rA.cross(c.normal)); + Vector3 inertia_B = inv_inertia_tensor_B.xform(c.rB.cross(c.normal)); + real_t kNormal = inv_mass_A + inv_mass_B; + kNormal += c.normal.dot(inertia_A.cross(c.rA)) + c.normal.dot(inertia_B.cross(c.rB)); + c.mass_normal = 1.0f / kNormal; + + c.bias = -bias * inv_dt * MIN(0.0f, -depth + max_penetration); + c.depth = depth; + + Vector3 j_vec = c.normal * c.acc_normal_impulse + c.acc_tangent_impulse; + + c.acc_impulse -= j_vec; + + // contact query reporting... + + if (A->can_report_contacts() || B->can_report_contacts()) { + Vector3 crB = B->get_angular_velocity().cross(c.rB) + B->get_linear_velocity(); + Vector3 crA = A->get_angular_velocity().cross(c.rA) + A->get_linear_velocity(); + + if (A->can_report_contacts()) { + 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); + } + + if (B->can_report_contacts()) { + 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); + } + } + + if (report_contacts_only) { + collided = false; + continue; + } + + 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(); + 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); +} |