virtualx-engine/servers/physics_3d/godot_collision_solver_3d.cpp
Rémi Verschelde d95794ec8a
One Copyright Update to rule them all
As many open source projects have started doing it, we're removing the
current year from the copyright notice, so that we don't need to bump
it every year.

It seems like only the first year of publication is technically
relevant for copyright notices, and even that seems to be something
that many companies stopped listing altogether (in a version controlled
codebase, the commits are a much better source of date of publication
than a hardcoded copyright statement).

We also now list Godot Engine contributors first as we're collectively
the current maintainers of the project, and we clarify that the
"exclusive" copyright of the co-founders covers the timespan before
opensourcing (their further contributions are included as part of Godot
Engine contributors).

Also fixed "cf." Frenchism - it's meant as "refer to / see".
2023-01-05 13:25:55 +01:00

585 lines
21 KiB
C++

/**************************************************************************/
/* godot_collision_solver_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_collision_solver_3d.h"
#include "godot_collision_solver_3d_sat.h"
#include "godot_soft_body_3d.h"
#include "gjk_epa.h"
#define collision_solver sat_calculate_penetration
//#define collision_solver gjk_epa_calculate_penetration
bool GodotCollisionSolver3D::solve_static_world_boundary(const GodotShape3D *p_shape_A, const Transform3D &p_transform_A, const GodotShape3D *p_shape_B, const Transform3D &p_transform_B, CallbackResult p_result_callback, void *p_userdata, bool p_swap_result, real_t p_margin) {
const GodotWorldBoundaryShape3D *world_boundary = static_cast<const GodotWorldBoundaryShape3D *>(p_shape_A);
if (p_shape_B->get_type() == PhysicsServer3D::SHAPE_WORLD_BOUNDARY) {
return false;
}
Plane p = p_transform_A.xform(world_boundary->get_plane());
static const int max_supports = 16;
Vector3 supports[max_supports];
int support_count;
GodotShape3D::FeatureType support_type = GodotShape3D::FeatureType::FEATURE_POINT;
p_shape_B->get_supports(p_transform_B.basis.xform_inv(-p.normal).normalized(), max_supports, supports, support_count, support_type);
if (support_type == GodotShape3D::FEATURE_CIRCLE) {
ERR_FAIL_COND_V(support_count != 3, false);
Vector3 circle_pos = supports[0];
Vector3 circle_axis_1 = supports[1] - circle_pos;
Vector3 circle_axis_2 = supports[2] - circle_pos;
// Use 3 equidistant points on the circle.
for (int i = 0; i < 3; ++i) {
Vector3 vertex_pos = circle_pos;
vertex_pos += circle_axis_1 * Math::cos(2.0 * Math_PI * i / 3.0);
vertex_pos += circle_axis_2 * Math::sin(2.0 * Math_PI * i / 3.0);
supports[i] = vertex_pos;
}
}
bool found = false;
for (int i = 0; i < support_count; i++) {
supports[i] += p_margin * supports[i].normalized();
supports[i] = p_transform_B.xform(supports[i]);
if (p.distance_to(supports[i]) >= 0) {
continue;
}
found = true;
Vector3 support_A = p.project(supports[i]);
if (p_result_callback) {
if (p_swap_result) {
p_result_callback(supports[i], 0, support_A, 0, p_userdata);
} else {
p_result_callback(support_A, 0, supports[i], 0, p_userdata);
}
}
}
return found;
}
bool GodotCollisionSolver3D::solve_separation_ray(const GodotShape3D *p_shape_A, const Transform3D &p_transform_A, const GodotShape3D *p_shape_B, const Transform3D &p_transform_B, CallbackResult p_result_callback, void *p_userdata, bool p_swap_result, real_t p_margin) {
const GodotSeparationRayShape3D *ray = static_cast<const GodotSeparationRayShape3D *>(p_shape_A);
Vector3 from = p_transform_A.origin;
Vector3 to = from + p_transform_A.basis.get_column(2) * (ray->get_length() + p_margin);
Vector3 support_A = to;
Transform3D ai = p_transform_B.affine_inverse();
from = ai.xform(from);
to = ai.xform(to);
Vector3 p, n;
if (!p_shape_B->intersect_segment(from, to, p, n, true)) {
return false;
}
// Discard contacts when the ray is fully contained inside the shape.
if (n == Vector3()) {
return false;
}
// Discard contacts in the wrong direction.
if (n.dot(from - to) < CMP_EPSILON) {
return false;
}
Vector3 support_B = p_transform_B.xform(p);
if (ray->get_slide_on_slope()) {
Vector3 global_n = ai.basis.xform_inv(n).normalized();
support_B = support_A + (support_B - support_A).length() * global_n;
}
if (p_result_callback) {
if (p_swap_result) {
p_result_callback(support_B, 0, support_A, 0, p_userdata);
} else {
p_result_callback(support_A, 0, support_B, 0, p_userdata);
}
}
return true;
}
struct _SoftBodyContactCollisionInfo {
int node_index = 0;
GodotCollisionSolver3D::CallbackResult result_callback = nullptr;
void *userdata = nullptr;
bool swap_result = false;
int contact_count = 0;
};
void GodotCollisionSolver3D::soft_body_contact_callback(const Vector3 &p_point_A, int p_index_A, const Vector3 &p_point_B, int p_index_B, void *p_userdata) {
_SoftBodyContactCollisionInfo &cinfo = *(static_cast<_SoftBodyContactCollisionInfo *>(p_userdata));
++cinfo.contact_count;
if (!cinfo.result_callback) {
return;
}
if (cinfo.swap_result) {
cinfo.result_callback(p_point_B, cinfo.node_index, p_point_A, p_index_A, cinfo.userdata);
} else {
cinfo.result_callback(p_point_A, p_index_A, p_point_B, cinfo.node_index, cinfo.userdata);
}
}
struct _SoftBodyQueryInfo {
GodotSoftBody3D *soft_body = nullptr;
const GodotShape3D *shape_A = nullptr;
const GodotShape3D *shape_B = nullptr;
Transform3D transform_A;
Transform3D node_transform;
_SoftBodyContactCollisionInfo contact_info;
#ifdef DEBUG_ENABLED
int node_query_count = 0;
int convex_query_count = 0;
#endif
};
bool GodotCollisionSolver3D::soft_body_query_callback(uint32_t p_node_index, void *p_userdata) {
_SoftBodyQueryInfo &query_cinfo = *(static_cast<_SoftBodyQueryInfo *>(p_userdata));
Vector3 node_position = query_cinfo.soft_body->get_node_position(p_node_index);
Transform3D transform_B;
transform_B.origin = query_cinfo.node_transform.xform(node_position);
query_cinfo.contact_info.node_index = p_node_index;
bool collided = solve_static(query_cinfo.shape_A, query_cinfo.transform_A, query_cinfo.shape_B, transform_B, soft_body_contact_callback, &query_cinfo.contact_info);
#ifdef DEBUG_ENABLED
++query_cinfo.node_query_count;
#endif
// Stop at first collision if contacts are not needed.
return (collided && !query_cinfo.contact_info.result_callback);
}
bool GodotCollisionSolver3D::soft_body_concave_callback(void *p_userdata, GodotShape3D *p_convex) {
_SoftBodyQueryInfo &query_cinfo = *(static_cast<_SoftBodyQueryInfo *>(p_userdata));
query_cinfo.shape_A = p_convex;
// Calculate AABB for internal soft body query (in world space).
AABB shape_aabb;
for (int i = 0; i < 3; i++) {
Vector3 axis;
axis[i] = 1.0;
real_t smin, smax;
p_convex->project_range(axis, query_cinfo.transform_A, smin, smax);
shape_aabb.position[i] = smin;
shape_aabb.size[i] = smax - smin;
}
shape_aabb.grow_by(query_cinfo.soft_body->get_collision_margin());
query_cinfo.soft_body->query_aabb(shape_aabb, soft_body_query_callback, &query_cinfo);
bool collided = (query_cinfo.contact_info.contact_count > 0);
#ifdef DEBUG_ENABLED
++query_cinfo.convex_query_count;
#endif
// Stop at first collision if contacts are not needed.
return (collided && !query_cinfo.contact_info.result_callback);
}
bool GodotCollisionSolver3D::solve_soft_body(const GodotShape3D *p_shape_A, const Transform3D &p_transform_A, const GodotShape3D *p_shape_B, const Transform3D &p_transform_B, CallbackResult p_result_callback, void *p_userdata, bool p_swap_result) {
const GodotSoftBodyShape3D *soft_body_shape_B = static_cast<const GodotSoftBodyShape3D *>(p_shape_B);
GodotSoftBody3D *soft_body = soft_body_shape_B->get_soft_body();
const Transform3D &world_to_local = soft_body->get_inv_transform();
const real_t collision_margin = soft_body->get_collision_margin();
GodotSphereShape3D sphere_shape;
sphere_shape.set_data(collision_margin);
_SoftBodyQueryInfo query_cinfo;
query_cinfo.contact_info.result_callback = p_result_callback;
query_cinfo.contact_info.userdata = p_userdata;
query_cinfo.contact_info.swap_result = p_swap_result;
query_cinfo.soft_body = soft_body;
query_cinfo.node_transform = p_transform_B * world_to_local;
query_cinfo.shape_A = p_shape_A;
query_cinfo.transform_A = p_transform_A;
query_cinfo.shape_B = &sphere_shape;
if (p_shape_A->is_concave()) {
// In case of concave shape, query convex shapes first.
const GodotConcaveShape3D *concave_shape_A = static_cast<const GodotConcaveShape3D *>(p_shape_A);
AABB soft_body_aabb = soft_body->get_bounds();
soft_body_aabb.grow_by(collision_margin);
// Calculate AABB for internal concave shape query (in local space).
AABB local_aabb;
for (int i = 0; i < 3; i++) {
Vector3 axis(p_transform_A.basis.get_column(i));
real_t axis_scale = 1.0 / axis.length();
real_t smin = soft_body_aabb.position[i];
real_t smax = smin + soft_body_aabb.size[i];
smin *= axis_scale;
smax *= axis_scale;
local_aabb.position[i] = smin;
local_aabb.size[i] = smax - smin;
}
concave_shape_A->cull(local_aabb, soft_body_concave_callback, &query_cinfo, true);
} else {
AABB shape_aabb = p_transform_A.xform(p_shape_A->get_aabb());
shape_aabb.grow_by(collision_margin);
soft_body->query_aabb(shape_aabb, soft_body_query_callback, &query_cinfo);
}
return (query_cinfo.contact_info.contact_count > 0);
}
struct _ConcaveCollisionInfo {
const Transform3D *transform_A = nullptr;
const GodotShape3D *shape_A = nullptr;
const Transform3D *transform_B = nullptr;
GodotCollisionSolver3D::CallbackResult result_callback = nullptr;
void *userdata = nullptr;
bool swap_result = false;
bool collided = false;
int aabb_tests = 0;
int collisions = 0;
bool tested = false;
real_t margin_A = 0.0f;
real_t margin_B = 0.0f;
Vector3 close_A;
Vector3 close_B;
};
bool GodotCollisionSolver3D::concave_callback(void *p_userdata, GodotShape3D *p_convex) {
_ConcaveCollisionInfo &cinfo = *(static_cast<_ConcaveCollisionInfo *>(p_userdata));
cinfo.aabb_tests++;
bool collided = collision_solver(cinfo.shape_A, *cinfo.transform_A, p_convex, *cinfo.transform_B, cinfo.result_callback, cinfo.userdata, cinfo.swap_result, nullptr, cinfo.margin_A, cinfo.margin_B);
if (!collided) {
return false;
}
cinfo.collided = true;
cinfo.collisions++;
// Stop at first collision if contacts are not needed.
return !cinfo.result_callback;
}
bool GodotCollisionSolver3D::solve_concave(const GodotShape3D *p_shape_A, const Transform3D &p_transform_A, const GodotShape3D *p_shape_B, const Transform3D &p_transform_B, CallbackResult p_result_callback, void *p_userdata, bool p_swap_result, real_t p_margin_A, real_t p_margin_B) {
const GodotConcaveShape3D *concave_B = static_cast<const GodotConcaveShape3D *>(p_shape_B);
_ConcaveCollisionInfo cinfo;
cinfo.transform_A = &p_transform_A;
cinfo.shape_A = p_shape_A;
cinfo.transform_B = &p_transform_B;
cinfo.result_callback = p_result_callback;
cinfo.userdata = p_userdata;
cinfo.swap_result = p_swap_result;
cinfo.collided = false;
cinfo.collisions = 0;
cinfo.margin_A = p_margin_A;
cinfo.margin_B = p_margin_B;
cinfo.aabb_tests = 0;
Transform3D rel_transform = p_transform_A;
rel_transform.origin -= p_transform_B.origin;
//quickly compute a local AABB
AABB local_aabb;
for (int i = 0; i < 3; i++) {
Vector3 axis(p_transform_B.basis.get_column(i));
real_t axis_scale = 1.0 / axis.length();
axis *= axis_scale;
real_t smin = 0.0, smax = 0.0;
p_shape_A->project_range(axis, rel_transform, smin, smax);
smin -= p_margin_A;
smax += p_margin_A;
smin *= axis_scale;
smax *= axis_scale;
local_aabb.position[i] = smin;
local_aabb.size[i] = smax - smin;
}
concave_B->cull(local_aabb, concave_callback, &cinfo, false);
return cinfo.collided;
}
bool GodotCollisionSolver3D::solve_static(const GodotShape3D *p_shape_A, const Transform3D &p_transform_A, const GodotShape3D *p_shape_B, const Transform3D &p_transform_B, CallbackResult p_result_callback, void *p_userdata, Vector3 *r_sep_axis, real_t p_margin_A, real_t p_margin_B) {
PhysicsServer3D::ShapeType type_A = p_shape_A->get_type();
PhysicsServer3D::ShapeType type_B = p_shape_B->get_type();
bool concave_A = p_shape_A->is_concave();
bool concave_B = p_shape_B->is_concave();
bool swap = false;
if (type_A > type_B) {
SWAP(type_A, type_B);
SWAP(concave_A, concave_B);
swap = true;
}
if (type_A == PhysicsServer3D::SHAPE_WORLD_BOUNDARY) {
if (type_B == PhysicsServer3D::SHAPE_WORLD_BOUNDARY) {
WARN_PRINT_ONCE("Collisions between world boundaries are not supported.");
return false;
}
if (type_B == PhysicsServer3D::SHAPE_SEPARATION_RAY) {
WARN_PRINT_ONCE("Collisions between world boundaries and rays are not supported.");
return false;
}
if (type_B == PhysicsServer3D::SHAPE_SOFT_BODY) {
WARN_PRINT_ONCE("Collisions between world boundaries and soft bodies are not supported.");
return false;
}
if (swap) {
return solve_static_world_boundary(p_shape_B, p_transform_B, p_shape_A, p_transform_A, p_result_callback, p_userdata, true, p_margin_A);
} else {
return solve_static_world_boundary(p_shape_A, p_transform_A, p_shape_B, p_transform_B, p_result_callback, p_userdata, false, p_margin_B);
}
} else if (type_A == PhysicsServer3D::SHAPE_SEPARATION_RAY) {
if (type_B == PhysicsServer3D::SHAPE_SEPARATION_RAY) {
WARN_PRINT_ONCE("Collisions between rays are not supported.");
return false;
}
if (swap) {
return solve_separation_ray(p_shape_B, p_transform_B, p_shape_A, p_transform_A, p_result_callback, p_userdata, true, p_margin_B);
} else {
return solve_separation_ray(p_shape_A, p_transform_A, p_shape_B, p_transform_B, p_result_callback, p_userdata, false, p_margin_A);
}
} else if (type_B == PhysicsServer3D::SHAPE_SOFT_BODY) {
if (type_A == PhysicsServer3D::SHAPE_SOFT_BODY) {
WARN_PRINT_ONCE("Collisions between soft bodies are not supported.");
return false;
}
if (swap) {
return solve_soft_body(p_shape_B, p_transform_B, p_shape_A, p_transform_A, p_result_callback, p_userdata, true);
} else {
return solve_soft_body(p_shape_A, p_transform_A, p_shape_B, p_transform_B, p_result_callback, p_userdata, false);
}
} else if (concave_B) {
if (concave_A) {
WARN_PRINT_ONCE("Collisions between two concave shapes are not supported.");
return false;
}
if (!swap) {
return solve_concave(p_shape_A, p_transform_A, p_shape_B, p_transform_B, p_result_callback, p_userdata, false, p_margin_A, p_margin_B);
} else {
return solve_concave(p_shape_B, p_transform_B, p_shape_A, p_transform_A, p_result_callback, p_userdata, true, p_margin_A, p_margin_B);
}
} else {
return collision_solver(p_shape_A, p_transform_A, p_shape_B, p_transform_B, p_result_callback, p_userdata, false, r_sep_axis, p_margin_A, p_margin_B);
}
}
bool GodotCollisionSolver3D::concave_distance_callback(void *p_userdata, GodotShape3D *p_convex) {
_ConcaveCollisionInfo &cinfo = *(static_cast<_ConcaveCollisionInfo *>(p_userdata));
cinfo.aabb_tests++;
Vector3 close_A, close_B;
cinfo.collided = !gjk_epa_calculate_distance(cinfo.shape_A, *cinfo.transform_A, p_convex, *cinfo.transform_B, close_A, close_B);
if (cinfo.collided) {
// No need to process any more result.
return true;
}
if (!cinfo.tested || close_A.distance_squared_to(close_B) < cinfo.close_A.distance_squared_to(cinfo.close_B)) {
cinfo.close_A = close_A;
cinfo.close_B = close_B;
cinfo.tested = true;
}
cinfo.collisions++;
return false;
}
bool GodotCollisionSolver3D::solve_distance_world_boundary(const GodotShape3D *p_shape_A, const Transform3D &p_transform_A, const GodotShape3D *p_shape_B, const Transform3D &p_transform_B, Vector3 &r_point_A, Vector3 &r_point_B) {
const GodotWorldBoundaryShape3D *world_boundary = static_cast<const GodotWorldBoundaryShape3D *>(p_shape_A);
if (p_shape_B->get_type() == PhysicsServer3D::SHAPE_WORLD_BOUNDARY) {
return false;
}
Plane p = p_transform_A.xform(world_boundary->get_plane());
static const int max_supports = 16;
Vector3 supports[max_supports];
int support_count;
GodotShape3D::FeatureType support_type;
Vector3 support_direction = p_transform_B.basis.xform_inv(-p.normal).normalized();
p_shape_B->get_supports(support_direction, max_supports, supports, support_count, support_type);
if (support_count == 0) { // This is a poor man's way to detect shapes that don't implement get_supports, such as GodotMotionShape3D.
Vector3 support_B = p_transform_B.xform(p_shape_B->get_support(support_direction));
r_point_A = p.project(support_B);
r_point_B = support_B;
bool collided = p.distance_to(support_B) <= 0;
return collided;
}
if (support_type == GodotShape3D::FEATURE_CIRCLE) {
ERR_FAIL_COND_V(support_count != 3, false);
Vector3 circle_pos = supports[0];
Vector3 circle_axis_1 = supports[1] - circle_pos;
Vector3 circle_axis_2 = supports[2] - circle_pos;
// Use 3 equidistant points on the circle.
for (int i = 0; i < 3; ++i) {
Vector3 vertex_pos = circle_pos;
vertex_pos += circle_axis_1 * Math::cos(2.0 * Math_PI * i / 3.0);
vertex_pos += circle_axis_2 * Math::sin(2.0 * Math_PI * i / 3.0);
supports[i] = vertex_pos;
}
}
bool collided = false;
Vector3 closest;
real_t closest_d = 0;
for (int i = 0; i < support_count; i++) {
supports[i] = p_transform_B.xform(supports[i]);
real_t d = p.distance_to(supports[i]);
if (i == 0 || d < closest_d) {
closest = supports[i];
closest_d = d;
if (d <= 0) {
collided = true;
}
}
}
r_point_A = p.project(closest);
r_point_B = closest;
return collided;
}
bool GodotCollisionSolver3D::solve_distance(const GodotShape3D *p_shape_A, const Transform3D &p_transform_A, const GodotShape3D *p_shape_B, const Transform3D &p_transform_B, Vector3 &r_point_A, Vector3 &r_point_B, const AABB &p_concave_hint, Vector3 *r_sep_axis) {
if (p_shape_B->get_type() == PhysicsServer3D::SHAPE_WORLD_BOUNDARY) {
Vector3 a, b;
bool col = solve_distance_world_boundary(p_shape_B, p_transform_B, p_shape_A, p_transform_A, a, b);
r_point_A = b;
r_point_B = a;
return !col;
} else if (p_shape_B->is_concave()) {
if (p_shape_A->is_concave()) {
return false;
}
const GodotConcaveShape3D *concave_B = static_cast<const GodotConcaveShape3D *>(p_shape_B);
_ConcaveCollisionInfo cinfo;
cinfo.transform_A = &p_transform_A;
cinfo.shape_A = p_shape_A;
cinfo.transform_B = &p_transform_B;
cinfo.result_callback = nullptr;
cinfo.userdata = nullptr;
cinfo.swap_result = false;
cinfo.collided = false;
cinfo.collisions = 0;
cinfo.aabb_tests = 0;
cinfo.tested = false;
Transform3D rel_transform = p_transform_A;
rel_transform.origin -= p_transform_B.origin;
//quickly compute a local AABB
bool use_cc_hint = p_concave_hint != AABB();
AABB cc_hint_aabb;
if (use_cc_hint) {
cc_hint_aabb = p_concave_hint;
cc_hint_aabb.position -= p_transform_B.origin;
}
AABB local_aabb;
for (int i = 0; i < 3; i++) {
Vector3 axis(p_transform_B.basis.get_column(i));
real_t axis_scale = ((real_t)1.0) / axis.length();
axis *= axis_scale;
real_t smin, smax;
if (use_cc_hint) {
cc_hint_aabb.project_range_in_plane(Plane(axis), smin, smax);
} else {
p_shape_A->project_range(axis, rel_transform, smin, smax);
}
smin *= axis_scale;
smax *= axis_scale;
local_aabb.position[i] = smin;
local_aabb.size[i] = smax - smin;
}
concave_B->cull(local_aabb, concave_distance_callback, &cinfo, false);
if (!cinfo.collided) {
r_point_A = cinfo.close_A;
r_point_B = cinfo.close_B;
}
return !cinfo.collided;
} else {
return gjk_epa_calculate_distance(p_shape_A, p_transform_A, p_shape_B, p_transform_B, r_point_A, r_point_B); //should pass sepaxis..
}
}