diff options
Diffstat (limited to 'servers')
| -rw-r--r-- | servers/physics_3d/godot_collision_solver_3d_sat.cpp | 415 |
1 files changed, 177 insertions, 238 deletions
diff --git a/servers/physics_3d/godot_collision_solver_3d_sat.cpp b/servers/physics_3d/godot_collision_solver_3d_sat.cpp index 36c47a07b9..d13f4ee801 100644 --- a/servers/physics_3d/godot_collision_solver_3d_sat.cpp +++ b/servers/physics_3d/godot_collision_solver_3d_sat.cpp @@ -758,24 +758,72 @@ public: typedef void (*CollisionFunc)(const GodotShape3D *, const Transform3D &, const GodotShape3D *, const Transform3D &, _CollectorCallback *p_callback, real_t, real_t); +// Perform analytic sphere-sphere collision and report results to collector template <bool withMargin> -static void _collision_sphere_sphere(const GodotShape3D *p_a, const Transform3D &p_transform_a, const GodotShape3D *p_b, const Transform3D &p_transform_b, _CollectorCallback *p_collector, real_t p_margin_a, real_t p_margin_b) { - const GodotSphereShape3D *sphere_A = static_cast<const GodotSphereShape3D *>(p_a); - const GodotSphereShape3D *sphere_B = static_cast<const GodotSphereShape3D *>(p_b); +static void analytic_sphere_collision(const Vector3 &p_origin_a, real_t p_radius_a, const Vector3 &p_origin_b, real_t p_radius_b, _CollectorCallback *p_collector, real_t p_margin_a, real_t p_margin_b) { + // Expand the spheres by the margins if enabled + if (withMargin) { + p_radius_a += p_margin_a; + p_radius_b += p_margin_b; + } - SeparatorAxisTest<GodotSphereShape3D, GodotSphereShape3D, withMargin> separator(sphere_A, p_transform_a, sphere_B, p_transform_b, p_collector, p_margin_a, p_margin_b); + // Get the vector from sphere B to A + Vector3 b_to_a = p_origin_a - p_origin_b; - // previous axis + // Get the length from B to A + real_t b_to_a_len = b_to_a.length(); - if (!separator.test_previous_axis()) { + // Calculate the sphere overlap, and bail if not overlapping + real_t overlap = p_radius_a + p_radius_b - b_to_a_len; + if (overlap < 0) return; - } - if (!separator.test_axis((p_transform_a.origin - p_transform_b.origin).normalized())) { + // Report collision + p_collector->collided = true; + + // Bail if there is no callback to receive the A and B collision points. + if (!p_collector->callback) { return; } - separator.generate_contacts(); + // Normalize the B to A vector + if (b_to_a_len < CMP_EPSILON) { + b_to_a = Vector3(0, 1, 0); // Spheres coincident, use arbitrary direction + } else { + b_to_a /= b_to_a_len; + } + + // Report collision points. The operations below are intended to minimize + // floating-point precision errors. This is done by calculating the first + // collision point from the smaller sphere, and then jumping across to + // the larger spheres collision point using the overlap distance. This + // jump is usually small even if the large sphere is massive, and so the + // second point will not suffer from precision errors. + if (p_radius_a < p_radius_b) { + Vector3 point_a = p_origin_a - b_to_a * p_radius_a; + Vector3 point_b = point_a + b_to_a * overlap; + p_collector->call(point_a, point_b); // Consider adding b_to_a vector + } else { + Vector3 point_b = p_origin_b + b_to_a * p_radius_b; + Vector3 point_a = point_b - b_to_a * overlap; + p_collector->call(point_a, point_b); // Consider adding b_to_a vector + } +} + +template <bool withMargin> +static void _collision_sphere_sphere(const GodotShape3D *p_a, const Transform3D &p_transform_a, const GodotShape3D *p_b, const Transform3D &p_transform_b, _CollectorCallback *p_collector, real_t p_margin_a, real_t p_margin_b) { + const GodotSphereShape3D *sphere_A = static_cast<const GodotSphereShape3D *>(p_a); + const GodotSphereShape3D *sphere_B = static_cast<const GodotSphereShape3D *>(p_b); + + // Perform an analytic sphere collision between the two spheres + analytic_sphere_collision<withMargin>( + p_transform_a.origin, + sphere_A->get_radius(), + p_transform_b.origin, + sphere_B->get_radius(), + p_collector, + p_margin_a, + p_margin_b); } template <bool withMargin> @@ -783,50 +831,36 @@ static void _collision_sphere_box(const GodotShape3D *p_a, const Transform3D &p_ const GodotSphereShape3D *sphere_A = static_cast<const GodotSphereShape3D *>(p_a); const GodotBoxShape3D *box_B = static_cast<const GodotBoxShape3D *>(p_b); - SeparatorAxisTest<GodotSphereShape3D, GodotBoxShape3D, withMargin> separator(sphere_A, p_transform_a, box_B, p_transform_b, p_collector, p_margin_a, p_margin_b); + // Find the point on the box nearest to the center of the sphere. - if (!separator.test_previous_axis()) { - return; - } + Vector3 center = p_transform_b.xform_inv(p_transform_a.origin); + Vector3 extents = box_B->get_half_extents(); + Vector3 nearest(MIN(MAX(center.x, -extents.x), extents.x), + MIN(MAX(center.y, -extents.y), extents.y), + MIN(MAX(center.z, -extents.z), extents.z)); + nearest = p_transform_b.xform(nearest); - // test faces + // See if it is inside the sphere. - for (int i = 0; i < 3; i++) { - Vector3 axis = p_transform_b.basis.get_column(i).normalized(); - - if (!separator.test_axis(axis)) { - return; - } + Vector3 delta = nearest - p_transform_a.origin; + real_t length = delta.length(); + if (length > sphere_A->get_radius() + p_margin_a + p_margin_b) { + return; } - - // calculate closest point to sphere - - Vector3 cnormal = p_transform_b.xform_inv(p_transform_a.origin); - - Vector3 cpoint = p_transform_b.xform(Vector3( - - (cnormal.x < 0) ? -box_B->get_half_extents().x : box_B->get_half_extents().x, - (cnormal.y < 0) ? -box_B->get_half_extents().y : box_B->get_half_extents().y, - (cnormal.z < 0) ? -box_B->get_half_extents().z : box_B->get_half_extents().z)); - - // use point to test axis - Vector3 point_axis = (p_transform_a.origin - cpoint).normalized(); - - if (!separator.test_axis(point_axis)) { + p_collector->collided = true; + if (!p_collector->callback) { return; } - - // test edges - - for (int i = 0; i < 3; i++) { - Vector3 axis = point_axis.cross(p_transform_b.basis.get_column(i)).cross(p_transform_b.basis.get_column(i)).normalized(); - - if (!separator.test_axis(axis)) { - return; - } + Vector3 axis; + if (length == 0) { + // The box passes through the sphere center. Select an axis based on the box's center. + axis = (p_transform_b.origin - nearest).normalized(); + } else { + axis = delta / length; } - - separator.generate_contacts(); + Vector3 point_a = p_transform_a.origin + (sphere_A->get_radius() + p_margin_a) * axis; + Vector3 point_b = (withMargin ? nearest + p_margin_b * axis : nearest); + p_collector->call(point_a, point_b); } template <bool withMargin> @@ -834,41 +868,66 @@ static void _collision_sphere_capsule(const GodotShape3D *p_a, const Transform3D const GodotSphereShape3D *sphere_A = static_cast<const GodotSphereShape3D *>(p_a); const GodotCapsuleShape3D *capsule_B = static_cast<const GodotCapsuleShape3D *>(p_b); - SeparatorAxisTest<GodotSphereShape3D, GodotCapsuleShape3D, withMargin> separator(sphere_A, p_transform_a, capsule_B, p_transform_b, p_collector, p_margin_a, p_margin_b); - - if (!separator.test_previous_axis()) { - return; - } - - //capsule sphere 1, sphere - - Vector3 capsule_axis = p_transform_b.basis.get_column(1) * (capsule_B->get_height() * 0.5 - capsule_B->get_radius()); - - Vector3 capsule_ball_1 = p_transform_b.origin + capsule_axis; + real_t capsule_B_radius = capsule_B->get_radius(); + + // Construct the capsule segment (ball-center to ball-center) + Vector3 capsule_segment[2]; + Vector3 capsule_axis = p_transform_b.basis.get_column(1) * (capsule_B->get_height() * 0.5 - capsule_B_radius); + capsule_segment[0] = p_transform_b.origin + capsule_axis; + capsule_segment[1] = p_transform_b.origin - capsule_axis; + + // Get the capsules closest segment-point to the sphere + Vector3 capsule_closest = Geometry3D::get_closest_point_to_segment(p_transform_a.origin, capsule_segment); + + // Perform an analytic sphere collision between the sphere and the sphere-collider in the capsule + analytic_sphere_collision<withMargin>( + p_transform_a.origin, + sphere_A->get_radius(), + capsule_closest, + capsule_B_radius, + p_collector, + p_margin_a, + p_margin_b); +} - if (!separator.test_axis((capsule_ball_1 - p_transform_a.origin).normalized())) { +template <bool withMargin> +static void analytic_sphere_cylinder_collision(real_t p_radius_a, real_t p_radius_b, real_t p_height_b, const Transform3D &p_transform_a, const Transform3D &p_transform_b, _CollectorCallback *p_collector, real_t p_margin_a, real_t p_margin_b) { + // Find the point on the cylinder nearest to the center of the sphere. + + Vector3 center = p_transform_b.xform_inv(p_transform_a.origin); + Vector3 nearest = center; + real_t radius = p_radius_b; + real_t r = Math::sqrt(center.x * center.x + center.z * center.z); + if (r > radius) { + real_t scale = radius / r; + nearest.x *= scale; + nearest.z *= scale; + } + real_t half_height = p_height_b / 2; + nearest.y = MIN(MAX(center.y, -half_height), half_height); + nearest = p_transform_b.xform(nearest); + + // See if it is inside the sphere. + + Vector3 delta = nearest - p_transform_a.origin; + real_t length = delta.length(); + if (length > p_radius_a + p_margin_a + p_margin_b) { return; } - - //capsule sphere 2, sphere - - Vector3 capsule_ball_2 = p_transform_b.origin - capsule_axis; - - if (!separator.test_axis((capsule_ball_2 - p_transform_a.origin).normalized())) { + p_collector->collided = true; + if (!p_collector->callback) { return; } - - //capsule edge, sphere - - Vector3 b2a = p_transform_a.origin - p_transform_b.origin; - - Vector3 axis = b2a.cross(capsule_axis).cross(capsule_axis).normalized(); - - if (!separator.test_axis(axis)) { - return; + Vector3 axis; + if (length == 0) { + // The cylinder passes through the sphere center. Select an axis based on the cylinder's center. + axis = (p_transform_b.origin - nearest).normalized(); + } else { + axis = delta / length; } - - separator.generate_contacts(); + Vector3 point_a = p_transform_a.origin + (p_radius_a + p_margin_a) * axis; + Vector3 point_b = (withMargin ? nearest + p_margin_b * axis : nearest); + p_collector->call(point_a, point_b); } template <bool withMargin> @@ -876,58 +935,7 @@ static void _collision_sphere_cylinder(const GodotShape3D *p_a, const Transform3 const GodotSphereShape3D *sphere_A = static_cast<const GodotSphereShape3D *>(p_a); const GodotCylinderShape3D *cylinder_B = static_cast<const GodotCylinderShape3D *>(p_b); - SeparatorAxisTest<GodotSphereShape3D, GodotCylinderShape3D, withMargin> separator(sphere_A, p_transform_a, cylinder_B, p_transform_b, p_collector, p_margin_a, p_margin_b); - - if (!separator.test_previous_axis()) { - return; - } - - // Cylinder B end caps. - Vector3 cylinder_B_axis = p_transform_b.basis.get_column(1).normalized(); - if (!separator.test_axis(cylinder_B_axis)) { - return; - } - - Vector3 cylinder_diff = p_transform_b.origin - p_transform_a.origin; - - // Cylinder B lateral surface. - if (!separator.test_axis(cylinder_B_axis.cross(cylinder_diff).cross(cylinder_B_axis).normalized())) { - return; - } - - // Closest point to cylinder caps. - const Vector3 &sphere_center = p_transform_a.origin; - Vector3 cyl_axis = p_transform_b.basis.get_column(1); - Vector3 cap_axis = p_transform_b.basis.get_column(0); - real_t height_scale = cyl_axis.length(); - real_t cap_dist = cylinder_B->get_height() * 0.5 * height_scale; - cyl_axis /= height_scale; - real_t radius_scale = cap_axis.length(); - real_t cap_radius = cylinder_B->get_radius() * radius_scale; - - for (int i = 0; i < 2; i++) { - Vector3 cap_dir = ((i == 0) ? cyl_axis : -cyl_axis); - Vector3 cap_pos = p_transform_b.origin + cap_dir * cap_dist; - - Vector3 closest_point; - - Vector3 diff = sphere_center - cap_pos; - Vector3 proj = diff - cap_dir.dot(diff) * cap_dir; - - real_t proj_len = proj.length(); - if (Math::is_zero_approx(proj_len)) { - // Point is equidistant to all circle points. - continue; - } - - closest_point = cap_pos + (cap_radius / proj_len) * proj; - - if (!separator.test_axis((closest_point - sphere_center).normalized())) { - return; - } - } - - separator.generate_contacts(); + analytic_sphere_cylinder_collision<withMargin>(sphere_A->get_radius(), cylinder_B->get_radius(), cylinder_B->get_height(), p_transform_a, p_transform_b, p_collector, p_margin_a, p_margin_b); } template <bool withMargin> @@ -1615,63 +1623,31 @@ static void _collision_capsule_capsule(const GodotShape3D *p_a, const Transform3 const GodotCapsuleShape3D *capsule_A = static_cast<const GodotCapsuleShape3D *>(p_a); const GodotCapsuleShape3D *capsule_B = static_cast<const GodotCapsuleShape3D *>(p_b); - SeparatorAxisTest<GodotCapsuleShape3D, GodotCapsuleShape3D, withMargin> separator(capsule_A, p_transform_a, capsule_B, p_transform_b, p_collector, p_margin_a, p_margin_b); - - if (!separator.test_previous_axis()) { - return; - } - - // some values - - Vector3 capsule_A_axis = p_transform_a.basis.get_column(1) * (capsule_A->get_height() * 0.5 - capsule_A->get_radius()); - Vector3 capsule_B_axis = p_transform_b.basis.get_column(1) * (capsule_B->get_height() * 0.5 - capsule_B->get_radius()); - - Vector3 capsule_A_ball_1 = p_transform_a.origin + capsule_A_axis; - Vector3 capsule_A_ball_2 = p_transform_a.origin - capsule_A_axis; - Vector3 capsule_B_ball_1 = p_transform_b.origin + capsule_B_axis; - Vector3 capsule_B_ball_2 = p_transform_b.origin - capsule_B_axis; - - //balls-balls - - if (!separator.test_axis((capsule_A_ball_1 - capsule_B_ball_1).normalized())) { - return; - } - if (!separator.test_axis((capsule_A_ball_1 - capsule_B_ball_2).normalized())) { - return; - } - - if (!separator.test_axis((capsule_A_ball_2 - capsule_B_ball_1).normalized())) { - return; - } - if (!separator.test_axis((capsule_A_ball_2 - capsule_B_ball_2).normalized())) { - return; - } - - // edges-balls - - if (!separator.test_axis((capsule_A_ball_1 - capsule_B_ball_1).cross(capsule_A_axis).cross(capsule_A_axis).normalized())) { - return; - } - - if (!separator.test_axis((capsule_A_ball_1 - capsule_B_ball_2).cross(capsule_A_axis).cross(capsule_A_axis).normalized())) { - return; - } - - if (!separator.test_axis((capsule_B_ball_1 - capsule_A_ball_1).cross(capsule_B_axis).cross(capsule_B_axis).normalized())) { - return; - } - - if (!separator.test_axis((capsule_B_ball_1 - capsule_A_ball_2).cross(capsule_B_axis).cross(capsule_B_axis).normalized())) { - return; - } - - // edges - - if (!separator.test_axis(capsule_A_axis.cross(capsule_B_axis).normalized())) { - return; - } - - separator.generate_contacts(); + real_t capsule_A_radius = capsule_A->get_radius(); + real_t capsule_B_radius = capsule_B->get_radius(); + + // Get the closest points between the capsule segments + Vector3 capsule_A_closest; + Vector3 capsule_B_closest; + Vector3 capsule_A_axis = p_transform_a.basis.get_column(1) * (capsule_A->get_height() * 0.5 - capsule_A_radius); + Vector3 capsule_B_axis = p_transform_b.basis.get_column(1) * (capsule_B->get_height() * 0.5 - capsule_B_radius); + Geometry3D::get_closest_points_between_segments( + p_transform_a.origin + capsule_A_axis, + p_transform_a.origin - capsule_A_axis, + p_transform_b.origin + capsule_B_axis, + p_transform_b.origin - capsule_B_axis, + capsule_A_closest, + capsule_B_closest); + + // Perform the analytic collision between the two closest capsule spheres + analytic_sphere_collision<withMargin>( + capsule_A_closest, + capsule_A_radius, + capsule_B_closest, + capsule_B_radius, + p_collector, + p_margin_a, + p_margin_b); } template <bool withMargin> @@ -1679,61 +1655,24 @@ static void _collision_capsule_cylinder(const GodotShape3D *p_a, const Transform const GodotCapsuleShape3D *capsule_A = static_cast<const GodotCapsuleShape3D *>(p_a); const GodotCylinderShape3D *cylinder_B = static_cast<const GodotCylinderShape3D *>(p_b); - SeparatorAxisTest<GodotCapsuleShape3D, GodotCylinderShape3D, withMargin> separator(capsule_A, p_transform_a, cylinder_B, p_transform_b, p_collector, p_margin_a, p_margin_b); - - if (!separator.test_previous_axis()) { - return; - } - - // Cylinder B end caps. - Vector3 cylinder_B_axis = p_transform_b.basis.get_column(1).normalized(); - if (!separator.test_axis(cylinder_B_axis)) { - return; - } - - // Cylinder edge against capsule balls. - - Vector3 capsule_A_axis = p_transform_a.basis.get_column(1); - - Vector3 capsule_A_ball_1 = p_transform_a.origin + capsule_A_axis * (capsule_A->get_height() * 0.5 - capsule_A->get_radius()); - Vector3 capsule_A_ball_2 = p_transform_a.origin - capsule_A_axis * (capsule_A->get_height() * 0.5 - capsule_A->get_radius()); - - if (!separator.test_axis((p_transform_b.origin - capsule_A_ball_1).cross(cylinder_B_axis).cross(cylinder_B_axis).normalized())) { - return; - } - - if (!separator.test_axis((p_transform_b.origin - capsule_A_ball_2).cross(cylinder_B_axis).cross(cylinder_B_axis).normalized())) { - return; - } - - // Cylinder edge against capsule edge. + // Find the closest points between the axes of the two objects. - Vector3 center_diff = p_transform_b.origin - p_transform_a.origin; - - if (!separator.test_axis(capsule_A_axis.cross(center_diff).cross(capsule_A_axis).normalized())) { - return; - } - - if (!separator.test_axis(cylinder_B_axis.cross(center_diff).cross(cylinder_B_axis).normalized())) { - return; - } - - real_t proj = capsule_A_axis.cross(cylinder_B_axis).cross(cylinder_B_axis).dot(capsule_A_axis); - if (Math::is_zero_approx(proj)) { - // Parallel capsule and cylinder axes, handle with specific axes only. - // Note: GJKEPA with no margin can lead to degenerate cases in this situation. - separator.generate_contacts(); - return; - } - - GodotCollisionSolver3D::CallbackResult callback = SeparatorAxisTest<GodotCapsuleShape3D, GodotCylinderShape3D, withMargin>::test_contact_points; - - // Fallback to generic algorithm to find the best separating axis. - if (!fallback_collision_solver(p_a, p_transform_a, p_b, p_transform_b, callback, &separator, false, p_margin_a, p_margin_b)) { - return; - } - - separator.generate_contacts(); + Vector3 capsule_A_closest; + Vector3 cylinder_B_closest; + Vector3 capsule_A_axis = p_transform_a.basis.get_column(1) * (capsule_A->get_height() * 0.5 - capsule_A->get_radius()); + Vector3 cylinder_B_axis = p_transform_b.basis.get_column(1) * (cylinder_B->get_height() * 0.5); + Geometry3D::get_closest_points_between_segments( + p_transform_a.origin + capsule_A_axis, + p_transform_a.origin - capsule_A_axis, + p_transform_b.origin + cylinder_B_axis, + p_transform_b.origin - cylinder_B_axis, + capsule_A_closest, + cylinder_B_closest); + + // Perform the collision test between the cylinder and the nearest sphere on the capsule axis. + + Transform3D sphere_transform(p_transform_a.basis, capsule_A_closest); + analytic_sphere_cylinder_collision<withMargin>(capsule_A->get_radius(), cylinder_B->get_radius(), cylinder_B->get_height(), sphere_transform, p_transform_b, p_collector, p_margin_a, p_margin_b); } template <bool withMargin> |