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Fix move_and_collide causing sliding on slopes

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Make sure the direction of the motion is preserved, unless the depth is
higher than the margin, which means the body needs depenetration in any
direction.

Also changed move_and_slide to avoid sliding on the first motion, in
order to avoid issues with unstable position on ground when jumping.

Co-authored-by: fabriceci <fabricecipolla@gmail.com>
This commit is contained in:
PouleyKetchoupp 2021-06-24 19:25:26 -07:00
parent 92f20fd70e
commit 9758a75221
10 changed files with 138 additions and 25 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
doc/classes/PhysicsTestMotionResult2D.xml
View File

@ -19,10 +19,16 @@
</member>
<member name="collider_velocity" type="Vector2" setter="" getter="get_collider_velocity" default="Vector2(0, 0)">
</member>
<member name="collision_depth" type="float" setter="" getter="get_collision_depth" default="0.0">
</member>
<member name="collision_normal" type="Vector2" setter="" getter="get_collision_normal" default="Vector2(0, 0)">
</member>
<member name="collision_point" type="Vector2" setter="" getter="get_collision_point" default="Vector2(0, 0)">
</member>
<member name="collision_safe_fraction" type="float" setter="" getter="get_collision_safe_fraction" default="0.0">
</member>
<member name="collision_unsafe_fraction" type="float" setter="" getter="get_collision_unsafe_fraction" default="0.0">
</member>
<member name="motion" type="Vector2" setter="" getter="get_motion" default="Vector2(0, 0)">
</member>
<member name="motion_remainder" type="Vector2" setter="" getter="get_motion_remainder" default="Vector2(0, 0)">

55
scene/2d/physics_body_2d.cpp
View File

@ -76,13 +76,46 @@ Ref<KinematicCollision2D> PhysicsBody2D::_move(const Vector2 &p_motion, bool p_i
return Ref<KinematicCollision2D>();
}
bool PhysicsBody2D::move_and_collide(const Vector2 &p_motion, bool p_infinite_inertia, PhysicsServer2D::MotionResult &r_result, real_t p_margin, bool p_exclude_raycast_shapes, bool p_test_only) {
bool PhysicsBody2D::move_and_collide(const Vector2 &p_motion, bool p_infinite_inertia, PhysicsServer2D::MotionResult &r_result, real_t p_margin, bool p_exclude_raycast_shapes, bool p_test_only, bool p_cancel_sliding) {
if (is_only_update_transform_changes_enabled()) {
ERR_PRINT("Move functions do not work together with 'sync to physics' option. Please read the documentation.");
}
Transform2D gt = get_global_transform();
bool colliding = PhysicsServer2D::get_singleton()->body_test_motion(get_rid(), gt, p_motion, p_infinite_inertia, p_margin, &r_result, p_exclude_raycast_shapes);
// Restore direction of motion to be along original motion,
// in order to avoid sliding due to recovery,
// but only if collision depth is low enough to avoid tunneling.
real_t motion_length = p_motion.length();
if (motion_length > CMP_EPSILON) {
real_t precision = 0.001;
if (colliding && p_cancel_sliding) {
// Can't just use margin as a threshold because collision depth is calculated on unsafe motion,
// so even in normal resting cases the depth can be a bit more than the margin.
precision += motion_length * (r_result.collision_unsafe_fraction - r_result.collision_safe_fraction);
if (r_result.collision_depth > (real_t)p_margin + precision) {
p_cancel_sliding = false;
}
}
if (p_cancel_sliding) {
// Check depth of recovery.
Vector2 motion_normal = p_motion / motion_length;
real_t dot = r_result.motion.dot(motion_normal);
Vector2 recovery = r_result.motion - motion_normal * dot;
real_t recovery_length = recovery.length();
// Fixes cases where canceling slide causes the motion to go too deep into the ground,
// Becauses we're only taking rest information into account and not general recovery.
if (recovery_length < (real_t)p_margin + precision) {
// Apply adjustment to motion.
r_result.motion = motion_normal * dot;
r_result.remainder = p_motion - r_result.motion;
}
}
}
if (!p_test_only) {
gt.elements[2] += r_result.motion;
set_global_transform(gt);
@ -942,15 +975,16 @@ void CharacterBody2D::move_and_slide() {
floor_normal = Vector2();
floor_velocity = Vector2();
int slide_count = max_slides;
while (slide_count) {
// No sliding on first attempt to keep floor motion stable when possible.
bool sliding_enabled = false;
for (int iteration = 0; iteration < max_slides; ++iteration) {
PhysicsServer2D::MotionResult result;
bool found_collision = false;
for (int i = 0; i < 2; ++i) {
bool collided;
if (i == 0) { //collide
collided = move_and_collide(motion, infinite_inertia, result, margin);
collided = move_and_collide(motion, infinite_inertia, result, margin, true, false, !sliding_enabled);
if (!collided) {
motion = Vector2(); //clear because no collision happened and motion completed
}
@ -966,7 +1000,6 @@ void CharacterBody2D::move_and_slide() {
found_collision = true;
motion_results.push_back(result);
motion = result.remainder;
if (up_direction == Vector2()) {
//all is a wall
@ -980,7 +1013,7 @@ void CharacterBody2D::move_and_slide() {
floor_velocity = result.collider_velocity;
if (stop_on_slope) {
if ((body_velocity_normal + up_direction).length() < 0.01 && result.motion.length() < 1) {
if ((body_velocity_normal + up_direction).length() < 0.01) {
Transform2D gt = get_global_transform();
gt.elements[2] -= result.motion.slide(up_direction);
set_global_transform(gt);
@ -995,16 +1028,20 @@ void CharacterBody2D::move_and_slide() {
}
}
motion = motion.slide(result.collision_normal);
if (sliding_enabled || !on_floor) {
motion = result.remainder.slide(result.collision_normal);
linear_velocity = linear_velocity.slide(result.collision_normal);
} else {
motion = result.remainder;
}
}
sliding_enabled = true;
}
if (!found_collision || motion == Vector2()) {
break;
}
--slide_count;
}
if (!was_on_floor || snap == Vector2()) {

2
scene/2d/physics_body_2d.h
View File

@ -50,7 +50,7 @@ protected:
Ref<KinematicCollision2D> _move(const Vector2 &p_motion, bool p_infinite_inertia = true, bool p_exclude_raycast_shapes = true, bool p_test_only = false, real_t p_margin = 0.08);
public:
bool move_and_collide(const Vector2 &p_motion, bool p_infinite_inertia, PhysicsServer2D::MotionResult &r_result, real_t p_margin, bool p_exclude_raycast_shapes = true, bool p_test_only = false);
bool move_and_collide(const Vector2 &p_motion, bool p_infinite_inertia, PhysicsServer2D::MotionResult &r_result, real_t p_margin, bool p_exclude_raycast_shapes = true, bool p_test_only = false, bool p_cancel_sliding = true);
bool test_move(const Transform2D &p_from, const Vector2 &p_motion, bool p_infinite_inertia = true, bool p_exclude_raycast_shapes = true, const Ref<KinematicCollision2D> &r_collision = Ref<KinematicCollision2D>(), real_t p_margin = 0.08);
TypedArray<PhysicsBody2D> get_collision_exceptions();

55
scene/3d/physics_body_3d.cpp
View File

@ -118,10 +118,43 @@ Ref<KinematicCollision3D> PhysicsBody3D::_move(const Vector3 &p_motion, bool p_i
return Ref<KinematicCollision3D>();
}
bool PhysicsBody3D::move_and_collide(const Vector3 &p_motion, bool p_infinite_inertia, PhysicsServer3D::MotionResult &r_result, real_t p_margin, bool p_exclude_raycast_shapes, bool p_test_only) {
bool PhysicsBody3D::move_and_collide(const Vector3 &p_motion, bool p_infinite_inertia, PhysicsServer3D::MotionResult &r_result, real_t p_margin, bool p_exclude_raycast_shapes, bool p_test_only, bool p_cancel_sliding) {
Transform3D gt = get_global_transform();
bool colliding = PhysicsServer3D::get_singleton()->body_test_motion(get_rid(), gt, p_motion, p_infinite_inertia, p_margin, &r_result, p_exclude_raycast_shapes);
// Restore direction of motion to be along original motion,
// in order to avoid sliding due to recovery,
// but only if collision depth is low enough to avoid tunneling.
real_t motion_length = p_motion.length();
if (motion_length > CMP_EPSILON) {
real_t precision = CMP_EPSILON;
if (colliding && p_cancel_sliding) {
// Can't just use margin as a threshold because collision depth is calculated on unsafe motion,
// so even in normal resting cases the depth can be a bit more than the margin.
precision += motion_length * (r_result.collision_unsafe_fraction - r_result.collision_safe_fraction);
if (r_result.collision_depth > (real_t)p_margin + precision) {
p_cancel_sliding = false;
}
}
if (p_cancel_sliding) {
// Check depth of recovery.
Vector3 motion_normal = p_motion / motion_length;
real_t dot = r_result.motion.dot(motion_normal);
Vector3 recovery = r_result.motion - motion_normal * dot;
real_t recovery_length = recovery.length();
// Fixes cases where canceling slide causes the motion to go too deep into the ground,
// Becauses we're only taking rest information into account and not general recovery.
if (recovery_length < (real_t)p_margin + precision) {
// Apply adjustment to motion.
r_result.motion = motion_normal * dot;
r_result.remainder = p_motion - r_result.motion;
}
}
}
for (int i = 0; i < 3; i++) {
if (locked_axis & (1 << i)) {
r_result.motion[i] = 0;
@ -978,15 +1011,16 @@ void CharacterBody3D::move_and_slide() {
floor_normal = Vector3();
floor_velocity = Vector3();
int slide_count = max_slides;
while (slide_count) {
// No sliding on first attempt to keep motion stable when possible.
bool sliding_enabled = false;
for (int iteration = 0; iteration < max_slides; ++iteration) {
PhysicsServer3D::MotionResult result;
bool found_collision = false;
for (int i = 0; i < 2; ++i) {
bool collided;
if (i == 0) { //collide
collided = move_and_collide(motion, infinite_inertia, result, margin);
collided = move_and_collide(motion, infinite_inertia, result, margin, true, false, !sliding_enabled);
if (!collided) {
motion = Vector3(); //clear because no collision happened and motion completed
}
@ -1002,7 +1036,6 @@ void CharacterBody3D::move_and_slide() {
found_collision = true;
motion_results.push_back(result);
motion = result.remainder;
if (up_direction == Vector3()) {
//all is a wall
@ -1016,7 +1049,7 @@ void CharacterBody3D::move_and_slide() {
floor_velocity = result.collider_velocity;
if (stop_on_slope) {
if ((body_velocity_normal + up_direction).length() < 0.01 && result.motion.length() < 1) {
if ((body_velocity_normal + up_direction).length() < 0.01) {
Transform3D gt = get_global_transform();
gt.origin -= result.motion.slide(up_direction);
set_global_transform(gt);
@ -1031,7 +1064,8 @@ void CharacterBody3D::move_and_slide() {
}
}
motion = motion.slide(result.collision_normal);
if (sliding_enabled || !on_floor) {
motion = result.remainder.slide(result.collision_normal);
linear_velocity = linear_velocity.slide(result.collision_normal);
for (int j = 0; j < 3; j++) {
@ -1039,14 +1073,17 @@ void CharacterBody3D::move_and_slide() {
linear_velocity[j] = 0.0;
}
}
} else {
motion = result.remainder;
}
}
sliding_enabled = true;
}
if (!found_collision || motion == Vector3()) {
break;
}
--slide_count;
}
if (!was_on_floor || snap == Vector3()) {

2
scene/3d/physics_body_3d.h
View File

@ -53,7 +53,7 @@ protected:
Ref<KinematicCollision3D> _move(const Vector3 &p_motion, bool p_infinite_inertia = true, bool p_exclude_raycast_shapes = true, bool p_test_only = false, real_t p_margin = 0.001);
public:
bool move_and_collide(const Vector3 &p_motion, bool p_infinite_inertia, PhysicsServer3D::MotionResult &r_result, real_t p_margin, bool p_exclude_raycast_shapes = true, bool p_test_only = false);
bool move_and_collide(const Vector3 &p_motion, bool p_infinite_inertia, PhysicsServer3D::MotionResult &r_result, real_t p_margin, bool p_exclude_raycast_shapes = true, bool p_test_only = false, bool p_cancel_sliding = true);
bool test_move(const Transform3D &p_from, const Vector3 &p_motion, bool p_infinite_inertia = true, bool p_exclude_raycast_shapes = true, const Ref<KinematicCollision3D> &r_collision = Ref<KinematicCollision3D>(), real_t p_margin = 0.001);
void set_axis_lock(PhysicsServer3D::BodyAxis p_axis, bool p_lock);

3
servers/physics_2d/space_2d_sw.cpp
View File

@ -1142,6 +1142,9 @@ bool Space2DSW::test_body_motion(Body2DSW *p_body, const Transform2D &p_from, co
r_result->collision_local_shape = rcd.best_local_shape;
r_result->collision_normal = rcd.best_normal;
r_result->collision_point = rcd.best_contact;
r_result->collision_depth = rcd.best_len;
r_result->collision_safe_fraction = safe;
r_result->collision_unsafe_fraction = unsafe;
r_result->collider_metadata = rcd.best_object->get_shape_metadata(rcd.best_shape);
const Body2DSW *body = static_cast<const Body2DSW *>(rcd.best_object);

3
servers/physics_3d/space_3d_sw.cpp
View File

@ -1032,6 +1032,9 @@ bool Space3DSW::test_body_motion(Body3DSW *p_body, const Transform3D &p_from, co
r_result->collision_local_shape = rcd.best_local_shape;
r_result->collision_normal = rcd.best_normal;
r_result->collision_point = rcd.best_contact;
r_result->collision_depth = rcd.best_len;
r_result->collision_safe_fraction = safe;
r_result->collision_unsafe_fraction = unsafe;
//r_result->collider_metadata = rcd.best_object->get_shape_metadata(rcd.best_shape);
const Body3DSW *body = static_cast<const Body3DSW *>(rcd.best_object);

18
servers/physics_server_2d.cpp
View File

@ -487,6 +487,18 @@ int PhysicsTestMotionResult2D::get_collider_shape() const {
return result.collider_shape;
}
real_t PhysicsTestMotionResult2D::get_collision_depth() const {
return result.collision_depth;
}
real_t PhysicsTestMotionResult2D::get_collision_safe_fraction() const {
return result.collision_safe_fraction;
}
real_t PhysicsTestMotionResult2D::get_collision_unsafe_fraction() const {
return result.collision_unsafe_fraction;
}
void PhysicsTestMotionResult2D::_bind_methods() {
ClassDB::bind_method(D_METHOD("get_motion"), &PhysicsTestMotionResult2D::get_motion);
ClassDB::bind_method(D_METHOD("get_motion_remainder"), &PhysicsTestMotionResult2D::get_motion_remainder);
@ -497,6 +509,9 @@ void PhysicsTestMotionResult2D::_bind_methods() {
ClassDB::bind_method(D_METHOD("get_collider_rid"), &PhysicsTestMotionResult2D::get_collider_rid);
ClassDB::bind_method(D_METHOD("get_collider"), &PhysicsTestMotionResult2D::get_collider);
ClassDB::bind_method(D_METHOD("get_collider_shape"), &PhysicsTestMotionResult2D::get_collider_shape);
ClassDB::bind_method(D_METHOD("get_collision_depth"), &PhysicsTestMotionResult2D::get_collision_depth);
ClassDB::bind_method(D_METHOD("get_collision_safe_fraction"), &PhysicsTestMotionResult2D::get_collision_safe_fraction);
ClassDB::bind_method(D_METHOD("get_collision_unsafe_fraction"), &PhysicsTestMotionResult2D::get_collision_unsafe_fraction);
ADD_PROPERTY(PropertyInfo(Variant::VECTOR2, "motion"), "", "get_motion");
ADD_PROPERTY(PropertyInfo(Variant::VECTOR2, "motion_remainder"), "", "get_motion_remainder");
@ -507,6 +522,9 @@ void PhysicsTestMotionResult2D::_bind_methods() {
ADD_PROPERTY(PropertyInfo(Variant::RID, "collider_rid"), "", "get_collider_rid");
ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "collider"), "", "get_collider");
ADD_PROPERTY(PropertyInfo(Variant::INT, "collider_shape"), "", "get_collider_shape");
ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "collision_depth"), "", "get_collision_depth");
ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "collision_safe_fraction"), "", "get_collision_safe_fraction");
ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "collision_unsafe_fraction"), "", "get_collision_unsafe_fraction");
}
///////////////////////////////////////

6
servers/physics_server_2d.h
View File

@ -493,6 +493,9 @@ public:
Vector2 collision_point;
Vector2 collision_normal;
Vector2 collider_velocity;
real_t collision_depth = 0.0;
real_t collision_safe_fraction = 0.0;
real_t collision_unsafe_fraction = 0.0;
int collision_local_shape = 0;
ObjectID collider_id;
RID collider;
@ -619,6 +622,9 @@ public:
RID get_collider_rid() const;
Object *get_collider() const;
int get_collider_shape() const;
real_t get_collision_depth() const;
real_t get_collision_safe_fraction() const;
real_t get_collision_unsafe_fraction() const;
};
typedef PhysicsServer2D *(*CreatePhysicsServer2DCallback)();

3
servers/physics_server_3d.h
View File

@ -497,6 +497,9 @@ public:
Vector3 collision_point;
Vector3 collision_normal;
Vector3 collider_velocity;
real_t collision_depth = 0.0;
real_t collision_safe_fraction = 0.0;
real_t collision_unsafe_fraction = 0.0;
int collision_local_shape = 0;
ObjectID collider_id;
RID collider;