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Improved logic for CharacterBody collision recovery depth

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Allows 2D character controller to work without applying gravity when
touching the ground (also more safely in 3D), and collision detection
is more flexible with different safe margin values.

Character body motion changes in 2D and 3D:
-Recovery only for depth > min contact depth to help with collision
detection consistency (rest info could be lost if recovery was too much)
-Adaptive min contact depth (based on margin) instead of space parameter

Extra CharacterBody changes:
-2D: apply changes made in 3D for stop on slope and floor snap that help
fixing some jittering cases
-3D: fix minor inconsistencies in stop on slope and floor snap logic
This commit is contained in:
PouleyKetchoupp 2021-09-16 18:38:17 -07:00
parent c1e6c2c49a
commit bf523a2b2a
14 changed files with 49 additions and 49 deletions
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2
doc/classes/CharacterBody2D.xml
View file

@ -133,7 +133,7 @@
<member name="floor_max_angle" type="float" setter="set_floor_max_angle" getter="get_floor_max_angle" default="0.785398">
Maximum angle (in radians) where a slope is still considered a floor (or a ceiling), rather than a wall, when calling [method move_and_slide]. The default value equals 45 degrees.
</member>
<member name="floor_snap_length" type="float" setter="set_floor_snap_length" getter="get_floor_snap_length" default="0.0">
<member name="floor_snap_length" type="float" setter="set_floor_snap_length" getter="get_floor_snap_length" default="1.0">
Sets a snapping distance. When set to a value different from [code]0.0[/code], the body is kept attached to slopes when calling [method move_and_slide]. The snapping vector is determined by the given distance along the opposite direction of the [member up_direction].
As long as the snapping vector is in contact with the ground and the body moves against `up_direction`, the body will remain attached to the surface. Snapping is not applied if the body moves along `up_direction`, so it will be able to detach from the ground when jumping.
</member>

2
doc/classes/PhysicsServer2D.xml
View file

@ -851,8 +851,6 @@
<constant name="SPACE_PARAM_CONSTRAINT_DEFAULT_BIAS" value="6" enum="SpaceParameter">
Constant to set/get the default solver bias for all physics constraints. A solver bias is a factor controlling how much two objects "rebound", after violating a constraint, to avoid leaving them in that state because of numerical imprecision.
</constant>
<constant name="SPACE_PARAM_TEST_MOTION_MIN_CONTACT_DEPTH" value="7" enum="SpaceParameter">
</constant>
<constant name="SHAPE_WORLD_BOUNDARY" value="0" enum="ShapeType">
This is the constant for creating world boundary shapes. A world boundary shape is an [i]infinite[/i] line with an origin point, and a normal. Thus, it can be used for front/behind checks.
</constant>

2
doc/classes/PhysicsServer3D.xml
View file

@ -1361,8 +1361,6 @@
<constant name="SPACE_PARAM_CONSTRAINT_DEFAULT_BIAS" value="7" enum="SpaceParameter">
Constant to set/get the default solver bias for all physics constraints. A solver bias is a factor controlling how much two objects "rebound", after violating a constraint, to avoid leaving them in that state because of numerical imprecision.
</constant>
<constant name="SPACE_PARAM_TEST_MOTION_MIN_CONTACT_DEPTH" value="8" enum="SpaceParameter">
</constant>
<constant name="BODY_AXIS_LINEAR_X" value="1" enum="BodyAxis">
</constant>
<constant name="BODY_AXIS_LINEAR_Y" value="2" enum="BodyAxis">

22
scene/2d/physics_body_2d.cpp
View file

@ -1089,9 +1089,7 @@ void CharacterBody2D::_move_and_slide_grounded(double p_delta, bool p_was_on_flo
if (on_floor && floor_stop_on_slope && (linear_velocity.normalized() + up_direction).length() < 0.01) {
Transform2D gt = get_global_transform();
if (result.travel.length() > margin) {
gt.elements[2] -= result.travel.slide(up_direction);
} else {
if (result.travel.length() <= margin + CMP_EPSILON) {
gt.elements[2] -= result.travel;
}
set_global_transform(gt);
@ -1110,7 +1108,7 @@ void CharacterBody2D::_move_and_slide_grounded(double p_delta, bool p_was_on_flo
// Avoid to move forward on a wall if floor_block_on_wall is true.
if (p_was_on_floor && !on_floor && !vel_dir_facing_up) {
// If the movement is large the body can be prevented from reaching the walls.
if (result.travel.length() <= margin) {
if (result.travel.length() <= margin + CMP_EPSILON) {
// Cancels the motion.
Transform2D gt = get_global_transform();
gt.elements[2] -= result.travel;
@ -1239,13 +1237,16 @@ void CharacterBody2D::_move_and_slide_free(double p_delta) {
}
void CharacterBody2D::_snap_on_floor(bool was_on_floor, bool vel_dir_facing_up) {
if (Math::is_equal_approx(floor_snap_length, 0) || on_floor || !was_on_floor || vel_dir_facing_up) {
if (on_floor || !was_on_floor || vel_dir_facing_up) {
return;
}
// Snap by at least collision margin to keep floor state consistent.
real_t length = MAX(floor_snap_length, margin);
Transform2D gt = get_global_transform();
PhysicsServer2D::MotionResult result;
if (move_and_collide(up_direction * -floor_snap_length, result, margin, true, false, true)) {
if (move_and_collide(-up_direction * length, result, margin, true, false, true)) {
bool apply = true;
if (result.get_angle(up_direction) <= floor_max_angle + FLOOR_ANGLE_THRESHOLD) {
on_floor = true;
@ -1273,12 +1274,15 @@ void CharacterBody2D::_snap_on_floor(bool was_on_floor, bool vel_dir_facing_up)
}
bool CharacterBody2D::_on_floor_if_snapped(bool was_on_floor, bool vel_dir_facing_up) {
if (Math::is_equal_approx(floor_snap_length, 0) || up_direction == Vector2() || on_floor || !was_on_floor || vel_dir_facing_up) {
if (up_direction == Vector2() || on_floor || !was_on_floor || vel_dir_facing_up) {
return false;
}
// Snap by at least collision margin to keep floor state consistent.
real_t length = MAX(floor_snap_length, margin);
PhysicsServer2D::MotionResult result;
if (move_and_collide(up_direction * -floor_snap_length, result, margin, true, false, true)) {
if (move_and_collide(-up_direction * length, result, margin, true, false, true)) {
if (result.get_angle(up_direction) <= floor_max_angle + FLOOR_ANGLE_THRESHOLD) {
return true;
}
@ -1566,7 +1570,7 @@ void CharacterBody2D::_bind_methods() {
ADD_PROPERTY(PropertyInfo(Variant::BOOL, "floor_constant_speed"), "set_floor_constant_speed_enabled", "is_floor_constant_speed_enabled");
ADD_PROPERTY(PropertyInfo(Variant::BOOL, "floor_block_on_wall"), "set_floor_block_on_wall_enabled", "is_floor_block_on_wall_enabled");
ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "floor_max_angle", PROPERTY_HINT_RANGE, "0,180,0.1,radians"), "set_floor_max_angle", "get_floor_max_angle");
ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "floor_snap_length", PROPERTY_HINT_RANGE, "0,1000,0.1"), "set_floor_snap_length", "get_floor_snap_length");
ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "floor_snap_length", PROPERTY_HINT_RANGE, "0,32,0.1,or_greater"), "set_floor_snap_length", "get_floor_snap_length");
ADD_GROUP("Moving platform", "moving_platform");
ADD_PROPERTY(PropertyInfo(Variant::INT, "moving_platform_floor_layers", PROPERTY_HINT_LAYERS_2D_PHYSICS), "set_moving_platform_floor_layers", "get_moving_platform_floor_layers");
ADD_PROPERTY(PropertyInfo(Variant::INT, "moving_platform_wall_layers", PROPERTY_HINT_LAYERS_2D_PHYSICS), "set_moving_platform_wall_layers", "get_moving_platform_wall_layers");

2
scene/2d/physics_body_2d.h
View file

@ -334,7 +334,7 @@ private:
int max_slides = 4;
int platform_layer;
real_t floor_max_angle = Math::deg2rad((real_t)45.0);
real_t floor_snap_length = 0;
real_t floor_snap_length = 1;
real_t free_mode_min_slide_angle = Math::deg2rad((real_t)15.0);
Vector2 up_direction = Vector2(0.0, -1.0);
uint32_t moving_platform_floor_layers = UINT32_MAX;

14
scene/3d/physics_body_3d.cpp
View file

@ -1145,8 +1145,7 @@ void CharacterBody3D::_move_and_slide_grounded(double p_delta, bool p_was_on_flo
if (collision_state.floor && floor_stop_on_slope && (linear_velocity.normalized() + up_direction).length() < 0.01) {
Transform3D gt = get_global_transform();
real_t travel_total = result.travel.length();
if (travel_total <= margin + CMP_EPSILON) {
if (result.travel.length() <= margin + CMP_EPSILON) {
gt.origin -= result.travel;
}
set_global_transform(gt);
@ -1185,7 +1184,7 @@ void CharacterBody3D::_move_and_slide_grounded(double p_delta, bool p_was_on_flo
Transform3D gt = get_global_transform();
real_t travel_total = result.travel.length();
real_t cancel_dist_max = MIN(0.1, margin * 20);
if (travel_total < margin + CMP_EPSILON) {
if (travel_total <= margin + CMP_EPSILON) {
gt.origin -= result.travel;
} else if (travel_total < cancel_dist_max) { // If the movement is large the body can be prevented from reaching the walls.
gt.origin -= result.travel.slide(up_direction);
@ -1376,7 +1375,9 @@ void CharacterBody3D::_snap_on_floor(bool was_on_floor, bool vel_dir_facing_up)
return;
}
// Snap by at least collision margin to keep floor state consistent.
real_t length = MAX(floor_snap_length, margin);
Transform3D gt = get_global_transform();
PhysicsServer3D::MotionResult result;
if (move_and_collide(-up_direction * length, result, margin, true, 4, false, true)) {
@ -1402,12 +1403,15 @@ void CharacterBody3D::_snap_on_floor(bool was_on_floor, bool vel_dir_facing_up)
}
bool CharacterBody3D::_on_floor_if_snapped(bool was_on_floor, bool vel_dir_facing_up) {
if (Math::is_zero_approx(floor_snap_length) || up_direction == Vector3() || collision_state.floor || !was_on_floor || vel_dir_facing_up) {
if (up_direction == Vector3() || collision_state.floor || !was_on_floor || vel_dir_facing_up) {
return false;
}
// Snap by at least collision margin to keep floor state consistent.
real_t length = MAX(floor_snap_length, margin);
PhysicsServer3D::MotionResult result;
if (move_and_collide(-up_direction * floor_snap_length, result, margin, true, 4, false, true)) {
if (move_and_collide(-up_direction * length, result, margin, true, 4, false, true)) {
CollisionState result_state;
// Don't apply direction for any type.
_set_collision_direction(result, result_state, CollisionState());

24
servers/physics_2d/space_2d_sw.cpp
View file

@ -34,6 +34,9 @@
#include "core/os/os.h"
#include "core/templates/pair.h"
#include "physics_server_2d_sw.h"
#define TEST_MOTION_MIN_CONTACT_DEPTH_FACTOR 0.05
_FORCE_INLINE_ static bool _can_collide_with(CollisionObject2DSW *p_object, uint32_t p_collision_mask, bool p_collide_with_bodies, bool p_collide_with_areas) {
if (!(p_object->get_collision_layer() & p_collision_mask)) {
return false;
@ -435,6 +438,8 @@ bool PhysicsDirectSpaceState2DSW::rest_info(RID p_shape, const Transform2D &p_sh
Shape2DSW *shape = PhysicsServer2DSW::singletonsw->shape_owner.getornull(p_shape);
ERR_FAIL_COND_V(!shape, 0);
real_t min_contact_depth = p_margin * TEST_MOTION_MIN_CONTACT_DEPTH_FACTOR;
Rect2 aabb = p_shape_xform.xform(shape->get_aabb());
aabb = aabb.merge(Rect2(aabb.position + p_motion, aabb.size)); //motion
aabb = aabb.grow(p_margin);
@ -445,7 +450,7 @@ bool PhysicsDirectSpaceState2DSW::rest_info(RID p_shape, const Transform2D &p_sh
rcd.best_len = 0;
rcd.best_object = nullptr;
rcd.best_shape = 0;
rcd.min_allowed_depth = space->test_motion_min_contact_depth;
rcd.min_allowed_depth = min_contact_depth;
for (int i = 0; i < amount; i++) {
if (!_can_collide_with(space->intersection_query_results[i], p_collision_mask, p_collide_with_bodies, p_collide_with_areas)) {
@ -569,6 +574,8 @@ bool Space2DSW::test_body_motion(Body2DSW *p_body, const Transform2D &p_from, co
ExcludedShapeSW excluded_shape_pairs[max_excluded_shape_pairs];
int excluded_shape_pair_count = 0;
real_t min_contact_depth = p_margin * TEST_MOTION_MIN_CONTACT_DEPTH_FACTOR;
real_t motion_length = p_motion.length();
Vector2 motion_normal = p_motion / motion_length;
@ -671,6 +678,8 @@ bool Space2DSW::test_body_motion(Body2DSW *p_body, const Transform2D &p_from, co
break;
}
recovered = true;
Vector2 recover_motion;
for (int i = 0; i < cbk.amount; i++) {
Vector2 a = sr[i * 2 + 0];
@ -682,9 +691,9 @@ bool Space2DSW::test_body_motion(Body2DSW *p_body, const Transform2D &p_from, co
// Compute depth on recovered motion.
real_t depth = n.dot(a + recover_motion) - d;
if (depth > 0.0) {
if (depth > min_contact_depth + CMP_EPSILON) {
// Only recover if there is penetration.
recover_motion -= n * depth * 0.4;
recover_motion -= n * (depth - min_contact_depth) * 0.4;
}
}
@ -693,8 +702,6 @@ bool Space2DSW::test_body_motion(Body2DSW *p_body, const Transform2D &p_from, co
break;
}
recovered = true;
body_transform.elements[2] += recover_motion;
body_aabb.position += recover_motion;
@ -870,7 +877,7 @@ bool Space2DSW::test_body_motion(Body2DSW *p_body, const Transform2D &p_from, co
rcd.best_shape = 0;
// Allowed depth can't be lower than motion length, in order to handle contacts at low speed.
rcd.min_allowed_depth = MIN(motion_length, test_motion_min_contact_depth);
rcd.min_allowed_depth = MIN(motion_length, min_contact_depth);
int from_shape = best_shape != -1 ? best_shape : 0;
int to_shape = best_shape != -1 ? best_shape + 1 : p_body->get_shape_count();
@ -1141,9 +1148,6 @@ void Space2DSW::set_param(PhysicsServer2D::SpaceParameter p_param, real_t p_valu
case PhysicsServer2D::SPACE_PARAM_CONSTRAINT_DEFAULT_BIAS:
constraint_bias = p_value;
break;
case PhysicsServer2D::SPACE_PARAM_TEST_MOTION_MIN_CONTACT_DEPTH:
test_motion_min_contact_depth = p_value;
break;
}
}
@ -1163,8 +1167,6 @@ real_t Space2DSW::get_param(PhysicsServer2D::SpaceParameter p_param) const {
return body_time_to_sleep;
case PhysicsServer2D::SPACE_PARAM_CONSTRAINT_DEFAULT_BIAS:
return constraint_bias;
case PhysicsServer2D::SPACE_PARAM_TEST_MOTION_MIN_CONTACT_DEPTH:
return test_motion_min_contact_depth;
}
return 0;
}

1
servers/physics_2d/space_2d_sw.h
View file

@ -102,7 +102,6 @@ private:
real_t contact_max_separation = 1.5;
real_t contact_max_allowed_penetration = 0.3;
real_t constraint_bias = 0.2;
real_t test_motion_min_contact_depth = 0.005;
enum {
INTERSECTION_QUERY_MAX = 2048

24
servers/physics_3d/space_3d_sw.cpp
View file

@ -34,6 +34,8 @@
#include "core/config/project_settings.h"
#include "physics_server_3d_sw.h"
#define TEST_MOTION_MIN_CONTACT_DEPTH_FACTOR 0.05
_FORCE_INLINE_ static bool _can_collide_with(CollisionObject3DSW *p_object, uint32_t p_collision_mask, bool p_collide_with_bodies, bool p_collide_with_areas) {
if (!(p_object->get_collision_layer() & p_collision_mask)) {
return false;
@ -488,13 +490,15 @@ bool PhysicsDirectSpaceState3DSW::rest_info(RID p_shape, const Transform3D &p_sh
Shape3DSW *shape = PhysicsServer3DSW::singletonsw->shape_owner.getornull(p_shape);
ERR_FAIL_COND_V(!shape, 0);
real_t min_contact_depth = p_margin * TEST_MOTION_MIN_CONTACT_DEPTH_FACTOR;
AABB aabb = p_shape_xform.xform(shape->get_aabb());
aabb = aabb.grow(p_margin);
int amount = space->broadphase->cull_aabb(aabb, space->intersection_query_results, Space3DSW::INTERSECTION_QUERY_MAX, space->intersection_query_subindex_results);
_RestCallbackData rcd;
rcd.min_allowed_depth = space->test_motion_min_contact_depth;
rcd.min_allowed_depth = min_contact_depth;
for (int i = 0; i < amount; i++) {
if (!_can_collide_with(space->intersection_query_results[i], p_collision_mask, p_collide_with_bodies, p_collide_with_areas)) {
@ -658,6 +662,8 @@ bool Space3DSW::test_body_motion(Body3DSW *p_body, const Transform3D &p_from, co
body_aabb = p_from.xform(p_body->get_inv_transform().xform(body_aabb));
body_aabb = body_aabb.grow(p_margin);
real_t min_contact_depth = p_margin * TEST_MOTION_MIN_CONTACT_DEPTH_FACTOR;
real_t motion_length = p_motion.length();
Vector3 motion_normal = p_motion / motion_length;
@ -711,8 +717,9 @@ bool Space3DSW::test_body_motion(Body3DSW *p_body, const Transform3D &p_from, co
break;
}
Vector3 recover_motion;
recovered = true;
Vector3 recover_motion;
for (int i = 0; i < cbk.amount; i++) {
Vector3 a = sr[i * 2 + 0];
Vector3 b = sr[i * 2 + 1];
@ -723,9 +730,9 @@ bool Space3DSW::test_body_motion(Body3DSW *p_body, const Transform3D &p_from, co
// Compute depth on recovered motion.
real_t depth = n.dot(a + recover_motion) - d;
if (depth > 0.0) {
if (depth > min_contact_depth + CMP_EPSILON) {
// Only recover if there is penetration.
recover_motion -= n * depth * 0.4;
recover_motion -= n * (depth - min_contact_depth) * 0.4;
}
}
@ -734,8 +741,6 @@ bool Space3DSW::test_body_motion(Body3DSW *p_body, const Transform3D &p_from, co
break;
}
recovered = true;
body_transform.origin += recover_motion;
body_aabb.position += recover_motion;
@ -889,7 +894,7 @@ bool Space3DSW::test_body_motion(Body3DSW *p_body, const Transform3D &p_from, co
}
// Allowed depth can't be lower than motion length, in order to handle contacts at low speed.
rcd.min_allowed_depth = MIN(motion_length, test_motion_min_contact_depth);
rcd.min_allowed_depth = MIN(motion_length, min_contact_depth);
int from_shape = best_shape != -1 ? best_shape : 0;
int to_shape = best_shape != -1 ? best_shape + 1 : p_body->get_shape_count();
@ -1158,9 +1163,6 @@ void Space3DSW::set_param(PhysicsServer3D::SpaceParameter p_param, real_t p_valu
case PhysicsServer3D::SPACE_PARAM_CONSTRAINT_DEFAULT_BIAS:
constraint_bias = p_value;
break;
case PhysicsServer3D::SPACE_PARAM_TEST_MOTION_MIN_CONTACT_DEPTH:
test_motion_min_contact_depth = p_value;
break;
}
}
@ -1182,8 +1184,6 @@ real_t Space3DSW::get_param(PhysicsServer3D::SpaceParameter p_param) const {
return body_angular_velocity_damp_ratio;
case PhysicsServer3D::SPACE_PARAM_CONSTRAINT_DEFAULT_BIAS:
return constraint_bias;
case PhysicsServer3D::SPACE_PARAM_TEST_MOTION_MIN_CONTACT_DEPTH:
return test_motion_min_contact_depth;
}
return 0;
}

1
servers/physics_3d/space_3d_sw.h
View file

@ -96,7 +96,6 @@ private:
real_t contact_max_separation = 0.05;
real_t contact_max_allowed_penetration = 0.01;
real_t constraint_bias = 0.01;
real_t test_motion_min_contact_depth = 0.00001;
enum {
INTERSECTION_QUERY_MAX = 2048

1
servers/physics_server_2d.cpp
View file

@ -670,7 +670,6 @@ void PhysicsServer2D::_bind_methods() {
BIND_ENUM_CONSTANT(SPACE_PARAM_BODY_ANGULAR_VELOCITY_SLEEP_THRESHOLD);
BIND_ENUM_CONSTANT(SPACE_PARAM_BODY_TIME_TO_SLEEP);
BIND_ENUM_CONSTANT(SPACE_PARAM_CONSTRAINT_DEFAULT_BIAS);
BIND_ENUM_CONSTANT(SPACE_PARAM_TEST_MOTION_MIN_CONTACT_DEPTH);
BIND_ENUM_CONSTANT(SHAPE_WORLD_BOUNDARY);
BIND_ENUM_CONSTANT(SHAPE_SEPARATION_RAY);

1
servers/physics_server_2d.h
View file

@ -262,7 +262,6 @@ public:
SPACE_PARAM_BODY_ANGULAR_VELOCITY_SLEEP_THRESHOLD,
SPACE_PARAM_BODY_TIME_TO_SLEEP,
SPACE_PARAM_CONSTRAINT_DEFAULT_BIAS,
SPACE_PARAM_TEST_MOTION_MIN_CONTACT_DEPTH,
};
virtual void space_set_param(RID p_space, SpaceParameter p_param, real_t p_value) = 0;

1
servers/physics_server_3d.cpp
View file

@ -867,7 +867,6 @@ void PhysicsServer3D::_bind_methods() {
BIND_ENUM_CONSTANT(SPACE_PARAM_BODY_TIME_TO_SLEEP);
BIND_ENUM_CONSTANT(SPACE_PARAM_BODY_ANGULAR_VELOCITY_DAMP_RATIO);
BIND_ENUM_CONSTANT(SPACE_PARAM_CONSTRAINT_DEFAULT_BIAS);
BIND_ENUM_CONSTANT(SPACE_PARAM_TEST_MOTION_MIN_CONTACT_DEPTH);
BIND_ENUM_CONSTANT(BODY_AXIS_LINEAR_X);
BIND_ENUM_CONSTANT(BODY_AXIS_LINEAR_Y);

1
servers/physics_server_3d.h
View file

@ -271,7 +271,6 @@ public:
SPACE_PARAM_BODY_TIME_TO_SLEEP,
SPACE_PARAM_BODY_ANGULAR_VELOCITY_DAMP_RATIO,
SPACE_PARAM_CONSTRAINT_DEFAULT_BIAS,
SPACE_PARAM_TEST_MOTION_MIN_CONTACT_DEPTH
};
virtual void space_set_param(RID p_space, SpaceParameter p_param, real_t p_value) = 0;