Merge pull request #20908 from AndreaCatania/kiSlope

Improved move_and_slide function stay on slope

modules/bullet/bullet_physics_server.cpp

@@ -869,6 +869,14 @@ bool BulletPhysicsServer::body_test_motion(RID p_body, const Transform &p_from,
 	return body->get_space()->test_body_motion(body, p_from, p_motion, p_infinite_inertia, r_result);
 }
 
+int BulletPhysicsServer::body_test_ray_separation(RID p_body, const Transform &p_transform, bool p_infinite_inertia, Vector3 &r_recover_motion, SeparationResult *r_results, int p_result_max, float p_margin) {
+	RigidBodyBullet *body = rigid_body_owner.get(p_body);
+	ERR_FAIL_COND_V(!body, 0);
+	ERR_FAIL_COND_V(!body->get_space(), 0);
+
+	return body->get_space()->test_ray_separation(body, p_transform, p_infinite_inertia, r_recover_motion, r_results, p_result_max, p_margin);
+}
+
 RID BulletPhysicsServer::soft_body_create(bool p_init_sleeping) {
 	SoftBodyBullet *body = bulletnew(SoftBodyBullet);
 	body->set_collision_layer(1);

modules/bullet/bullet_physics_server.h

@@ -259,6 +259,7 @@ public:
 	virtual PhysicsDirectBodyState *body_get_direct_state(RID p_body);
 
 	virtual bool body_test_motion(RID p_body, const Transform &p_from, const Vector3 &p_motion, bool p_infinite_inertia, MotionResult *r_result = NULL);
+	virtual int body_test_ray_separation(RID p_body, const Transform &p_transform, bool p_infinite_inertia, Vector3 &r_recover_motion, SeparationResult *r_results, int p_result_max, float p_margin = 0.001);
 
 	/* SOFT BODY API */
 

modules/bullet/godot_result_callbacks.cpp

@@ -260,10 +260,19 @@ void GodotDeepPenetrationContactResultCallback::addContactPoint(const btVector3
 
 	if (m_penetration_distance > depth) { // Has penetration?
 
-		bool isSwapped = m_manifoldPtr->getBody0() != m_body0Wrap->getCollisionObject();
+		const bool isSwapped = m_manifoldPtr->getBody0() != m_body0Wrap->getCollisionObject();
 		m_penetration_distance = depth;
 		m_other_compound_shape_index = isSwapped ? m_index0 : m_index1;
-		m_pointNormalWorld = isSwapped ? normalOnBInWorld * -1 : normalOnBInWorld;
 		m_pointWorld = isSwapped ? (pointInWorldOnB + (normalOnBInWorld * depth)) : pointInWorldOnB;
+
+		const btCollisionObjectWrapper *bw0 = m_body0Wrap;
+		if (isSwapped)
+			bw0 = m_body1Wrap;
+
+		if (bw0->getCollisionShape()->getShapeType() == CUSTOM_CONVEX_SHAPE_TYPE) {
+			m_pointNormalWorld = bw0->m_worldTransform.getBasis().transpose() * btVector3(0, 0, 1);
+		} else {
+			m_pointNormalWorld = isSwapped ? normalOnBInWorld * -1 : normalOnBInWorld;
+		}
 	}
 }

modules/bullet/space_bullet.cpp

@@ -894,6 +894,12 @@ bool SpaceBullet::test_body_motion(RigidBodyBullet *p_body, const Transform &p_f
 				// Skip no convex shape
 				continue;
 			}
+
+			if (p_body->get_bt_shape(shIndex)->getShapeType() == CUSTOM_CONVEX_SHAPE_TYPE) {
+				// Skip rayshape in order to implement custom separation process
+				continue;
+			}
+
 			btConvexShape *convex_shape_test(static_cast<btConvexShape *>(p_body->get_bt_shape(shIndex)));
 
 			btTransform shape_world_from = body_transform * p_body->get_kinematic_utilities()->shapes[shIndex].transform;
@@ -924,11 +930,11 @@ bool SpaceBullet::test_body_motion(RigidBodyBullet *p_body, const Transform &p_f
 		btVector3 __rec(0, 0, 0);
 		RecoverResult r_recover_result;
 
-		has_penetration = recover_from_penetration(p_body, body_transform, 0, p_infinite_inertia, __rec, &r_recover_result);
+		has_penetration = recover_from_penetration(p_body, body_transform, 1, p_infinite_inertia, __rec, &r_recover_result);
 
 		// Parse results
 		if (r_result) {
-			B_TO_G(motion + initial_recover_motion, r_result->motion);
+			B_TO_G(motion + initial_recover_motion + __rec, r_result->motion);
 
 			if (has_penetration) {
 
@@ -964,6 +970,39 @@ bool SpaceBullet::test_body_motion(RigidBodyBullet *p_body, const Transform &p_f
 	return has_penetration;
 }
 
+int SpaceBullet::test_ray_separation(RigidBodyBullet *p_body, const Transform &p_transform, bool p_infinite_inertia, Vector3 &r_recover_motion, PhysicsServer::SeparationResult *r_results, int p_result_max, float p_margin) {
+
+	btTransform body_transform;
+	G_TO_B(p_transform, body_transform);
+	UNSCALE_BT_BASIS(body_transform);
+
+	btVector3 recover_motion(0, 0, 0);
+
+	int rays_found;
+
+	for (int t(RECOVERING_MOVEMENT_CYCLES); 0 < t; --t) {
+		int last_ray_index = recover_from_penetration_ray(p_body, body_transform, RECOVERING_MOVEMENT_SCALE, p_infinite_inertia, p_result_max, recover_motion, r_results);
+
+		rays_found = MAX(last_ray_index, rays_found);
+		if (!rays_found) {
+			break;
+		} else {
+			body_transform.getOrigin() += recover_motion;
+		}
+	}
+
+	//optimize results (remove non colliding)
+	for (int i = 0; i < rays_found; i++) {
+		if (r_results[i].collision_depth >= 0) {
+			rays_found--;
+			SWAP(r_results[i], r_results[rays_found]);
+		}
+	}
+
+	B_TO_G(recover_motion, r_recover_motion);
+	return rays_found;
+}
+
 struct RecoverPenetrationBroadPhaseCallback : public btBroadphaseAabbCallback {
 private:
 	const btCollisionObject *self_collision_object;
@@ -1020,6 +1059,11 @@ bool SpaceBullet::recover_from_penetration(RigidBodyBullet *p_body, const btTran
 			continue;
 		}
 
+		if (kin_shape.shape->getShapeType() == CUSTOM_CONVEX_SHAPE_TYPE) {
+			// Skip rayshape in order to implement custom separation process
+			continue;
+		}
+
 		body_shape_position = p_body_position * kin_shape.transform;
 		body_shape_position_recovered = body_shape_position;
 		body_shape_position_recovered.getOrigin() += r_delta_recover_movement;
@@ -1122,7 +1166,6 @@ bool SpaceBullet::RFP_convex_world_test(const btConvexShape *p_shapeA, const btC
 
 		if (contactPointResult.hasHit()) {
 			r_delta_recover_movement += contactPointResult.m_pointNormalWorld * (contactPointResult.m_penetration_distance * -1 * p_recover_movement_scale);
-
 			if (r_recover_result) {
 				if (contactPointResult.m_penetration_distance < r_recover_result->penetration_distance) {
 					r_recover_result->hasPenetration = true;
@@ -1138,3 +1181,79 @@ bool SpaceBullet::RFP_convex_world_test(const btConvexShape *p_shapeA, const btC
 	}
 	return false;
 }
+
+int SpaceBullet::recover_from_penetration_ray(RigidBodyBullet *p_body, const btTransform &p_body_position, btScalar p_recover_movement_scale, bool p_infinite_inertia, int p_result_max, btVector3 &r_delta_recover_movement, PhysicsServer::SeparationResult *r_results) {
+
+	RecoverPenetrationBroadPhaseCallback recover_broad_result(p_body->get_bt_collision_object(), p_body->get_collision_layer(), p_body->get_collision_mask());
+
+	btTransform body_shape_position;
+	btTransform body_shape_position_recovered;
+
+	// Broad phase support
+	btVector3 minAabb, maxAabb;
+
+	int ray_index = 0;
+
+	// For each shape
+	for (int kinIndex = p_body->get_kinematic_utilities()->shapes.size() - 1; 0 <= kinIndex; --kinIndex) {
+
+		recover_broad_result.reset();
+
+		if (ray_index >= p_result_max) {
+			break;
+		}
+
+		const RigidBodyBullet::KinematicShape &kin_shape(p_body->get_kinematic_utilities()->shapes[kinIndex]);
+		if (!kin_shape.is_active()) {
+			continue;
+		}
+
+		if (kin_shape.shape->getShapeType() != CUSTOM_CONVEX_SHAPE_TYPE) {
+			continue;
+		}
+
+		body_shape_position = p_body_position * kin_shape.transform;
+		body_shape_position_recovered = body_shape_position;
+		body_shape_position_recovered.getOrigin() += r_delta_recover_movement;
+
+		kin_shape.shape->getAabb(body_shape_position_recovered, minAabb, maxAabb);
+		dynamicsWorld->getBroadphase()->aabbTest(minAabb, maxAabb, recover_broad_result);
+
+		for (int i = recover_broad_result.result_collision_objects.size() - 1; 0 <= i; --i) {
+			btCollisionObject *otherObject = recover_broad_result.result_collision_objects[i];
+			if (p_infinite_inertia && !otherObject->isStaticOrKinematicObject()) {
+				otherObject->activate(); // Force activation of hitten rigid, soft body
+				continue;
+			} else if (!p_body->get_bt_collision_object()->checkCollideWith(otherObject) || !otherObject->checkCollideWith(p_body->get_bt_collision_object()))
+				continue;
+
+			if (otherObject->getCollisionShape()->isCompound()) {
+
+				// Each convex shape
+				btCompoundShape *cs = static_cast<btCompoundShape *>(otherObject->getCollisionShape());
+				for (int x = cs->getNumChildShapes() - 1; 0 <= x; --x) {
+
+					RecoverResult r_recover_result;
+					if (RFP_convex_world_test(kin_shape.shape, cs->getChildShape(x), p_body->get_bt_collision_object(), otherObject, kinIndex, x, body_shape_position, otherObject->getWorldTransform() * cs->getChildTransform(x), p_recover_movement_scale, r_delta_recover_movement, &r_recover_result)) {
+
+						const btRigidBody *btRigid = static_cast<const btRigidBody *>(otherObject);
+						CollisionObjectBullet *collisionObject = static_cast<CollisionObjectBullet *>(otherObject->getUserPointer());
+
+						r_results[ray_index].collision_depth = r_recover_result.penetration_distance;
+						B_TO_G(r_recover_result.pointWorld, r_results[ray_index].collision_point);
+						B_TO_G(r_recover_result.normal, r_results[ray_index].collision_normal);
+						B_TO_G(btRigid->getVelocityInLocalPoint(r_recover_result.pointWorld - btRigid->getWorldTransform().getOrigin()), r_results[ray_index].collider_velocity);
+						r_results[ray_index].collision_local_shape = kinIndex;
+						r_results[ray_index].collider_id = collisionObject->get_instance_id();
+						r_results[ray_index].collider = collisionObject->get_self();
+						r_results[ray_index].collider_shape = r_recover_result.other_compound_shape_index;
+					}
+				}
+			}
+		}
+
+		++ray_index;
+	}
+
+	return ray_index;
+}

modules/bullet/space_bullet.h

@@ -175,6 +175,7 @@ public:
 	void update_gravity();
 
 	bool test_body_motion(RigidBodyBullet *p_body, const Transform &p_from, const Vector3 &p_motion, bool p_infinite_inertia, PhysicsServer::MotionResult *r_result);
+	int test_ray_separation(RigidBodyBullet *p_body, const Transform &p_transform, bool p_infinite_inertia, Vector3 &r_recover_motion, PhysicsServer::SeparationResult *r_results, int p_result_max, float p_margin);
 
 private:
 	void create_empty_world(bool p_create_soft_world);
@@ -208,5 +209,7 @@ private:
 	/// This is an API that recover a kinematic object from penetration
 	/// Using this we leave Bullet to select the best algorithm, For example GJK in case we have Convex Convex, or a Bullet accelerated algorithm
 	bool RFP_convex_world_test(const btConvexShape *p_shapeA, const btCollisionShape *p_shapeB, btCollisionObject *p_objectA, btCollisionObject *p_objectB, int p_shapeId_A, int p_shapeId_B, const btTransform &p_transformA, const btTransform &p_transformB, btScalar p_recover_movement_scale, btVector3 &r_delta_recover_movement, RecoverResult *r_recover_result = NULL);
+
+	int recover_from_penetration_ray(RigidBodyBullet *p_body, const btTransform &p_body_position, btScalar p_recover_movement_scale, bool p_infinite_inertia, int p_result_max, btVector3 &r_delta_recover_movement, PhysicsServer::SeparationResult *r_results);
 };
 #endif

scene/2d/physics_body_2d.cpp

@@ -1207,7 +1207,7 @@ bool KinematicBody2D::move_and_collide(const Vector2 &p_motion, bool p_infinite_
 //so, if you pass 45 as limit, avoid numerical precision erros when angle is 45.
 #define FLOOR_ANGLE_THRESHOLD 0.01
 
-Vector2 KinematicBody2D::move_and_slide(const Vector2 &p_linear_velocity, const Vector2 &p_floor_direction, bool p_infinite_inertia, float p_slope_stop_min_velocity, int p_max_slides, float p_floor_max_angle) {
+Vector2 KinematicBody2D::move_and_slide(const Vector2 &p_linear_velocity, const Vector2 &p_floor_direction, bool p_infinite_inertia, bool p_stop_on_slope, int p_max_slides, float p_floor_max_angle) {
 
 	Vector2 floor_motion = floor_velocity;
 	if (on_floor && on_floor_body.is_valid()) {
@@ -1228,6 +1228,8 @@ Vector2 KinematicBody2D::move_and_slide(const Vector2 &p_linear_velocity, const
 	colliders.clear();
 	floor_velocity = Vector2();
 
+	Vector2 lv_n = p_linear_velocity.normalized();
+
 	while (p_max_slides) {
 
 		Collision collision;
@@ -1254,8 +1256,10 @@ Vector2 KinematicBody2D::move_and_slide(const Vector2 &p_linear_velocity, const
 
 			if (collided) {
 
+				colliders.push_back(collision);
 				motion = collision.remainder;
 
+				bool is_on_slope = false;
 				if (p_floor_direction == Vector2()) {
 					//all is a wall
 					on_wall = true;
@@ -1266,15 +1270,17 @@ Vector2 KinematicBody2D::move_and_slide(const Vector2 &p_linear_velocity, const
 						on_floor_body = collision.collider_rid;
 						floor_velocity = collision.collider_vel;
 
-						Vector2 rel_v = lv - floor_velocity;
-						Vector2 hv = rel_v - p_floor_direction * p_floor_direction.dot(rel_v);
-
-						if (collision.travel.length() < 1 && hv.length() < p_slope_stop_min_velocity) {
-							Transform2D gt = get_global_transform();
-							gt.elements[2] -= collision.travel;
-							set_global_transform(gt);
-							return Vector2();
+						if (p_stop_on_slope) {
+							if (Vector2() == lv_n + p_floor_direction) {
+								Transform2D gt = get_global_transform();
+								gt.elements[2] -= collision.travel;
+								set_global_transform(gt);
+								return Vector2();
+							}
 						}
+
+						is_on_slope = true;
+
 					} else if (collision.normal.dot(-p_floor_direction) >= Math::cos(p_floor_max_angle + FLOOR_ANGLE_THRESHOLD)) { //ceiling
 						on_ceiling = true;
 					} else {
@@ -1282,12 +1288,18 @@ Vector2 KinematicBody2D::move_and_slide(const Vector2 &p_linear_velocity, const
 					}
 				}
 
-				Vector2 n = collision.normal;
-				motion = motion.slide(n);
-				lv = lv.slide(n);
-
-				colliders.push_back(collision);
+				if (p_stop_on_slope && is_on_slope) {
+					motion = motion.slide(p_floor_direction);
+					lv = lv.slide(p_floor_direction);
+				} else {
+					Vector2 n = collision.normal;
+					motion = motion.slide(n);
+					lv = lv.slide(n);
+				}
 			}
+
+			if (p_stop_on_slope)
+				break;
 		}
 
 		if (!found_collision) {
@@ -1301,11 +1313,11 @@ Vector2 KinematicBody2D::move_and_slide(const Vector2 &p_linear_velocity, const
 	return lv;
 }
 
-Vector2 KinematicBody2D::move_and_slide_with_snap(const Vector2 &p_linear_velocity, const Vector2 &p_snap, const Vector2 &p_floor_direction, bool p_infinite_inertia, float p_slope_stop_min_velocity, int p_max_slides, float p_floor_max_angle) {
+Vector2 KinematicBody2D::move_and_slide_with_snap(const Vector2 &p_linear_velocity, const Vector2 &p_snap, const Vector2 &p_floor_direction, bool p_infinite_inertia, bool p_stop_on_slope, int p_max_slides, float p_floor_max_angle) {
 
 	bool was_on_floor = on_floor;
 
-	Vector2 ret = move_and_slide(p_linear_velocity, p_floor_direction, p_infinite_inertia, p_slope_stop_min_velocity, p_max_slides, p_floor_max_angle);
+	Vector2 ret = move_and_slide(p_linear_velocity, p_floor_direction, p_infinite_inertia, p_stop_on_slope, p_max_slides, p_floor_max_angle);
 	if (!was_on_floor || p_snap == Vector2()) {
 		return ret;
 	}
@@ -1439,8 +1451,8 @@ void KinematicBody2D::_notification(int p_what) {
 void KinematicBody2D::_bind_methods() {
 
 	ClassDB::bind_method(D_METHOD("move_and_collide", "rel_vec", "infinite_inertia", "exclude_raycast_shapes", "test_only"), &KinematicBody2D::_move, DEFVAL(true), DEFVAL(true), DEFVAL(false));
-	ClassDB::bind_method(D_METHOD("move_and_slide", "linear_velocity", "floor_normal", "infinite_inertia", "slope_stop_min_velocity", "max_bounces", "floor_max_angle"), &KinematicBody2D::move_and_slide, DEFVAL(Vector2(0, 0)), DEFVAL(true), DEFVAL(5), DEFVAL(4), DEFVAL(Math::deg2rad((float)45)));
-	ClassDB::bind_method(D_METHOD("move_and_slide_with_snap", "linear_velocity", "snap", "floor_normal", "infinite_inertia", "slope_stop_min_velocity", "max_bounces", "floor_max_angle"), &KinematicBody2D::move_and_slide_with_snap, DEFVAL(Vector2(0, 0)), DEFVAL(true), DEFVAL(5), DEFVAL(4), DEFVAL(Math::deg2rad((float)45)));
+	ClassDB::bind_method(D_METHOD("move_and_slide", "linear_velocity", "floor_normal", "infinite_inertia", "stop_on_slope", "max_bounces", "floor_max_angle"), &KinematicBody2D::move_and_slide, DEFVAL(Vector2(0, 0)), DEFVAL(true), DEFVAL(false), DEFVAL(4), DEFVAL(Math::deg2rad((float)45)));
+	ClassDB::bind_method(D_METHOD("move_and_slide_with_snap", "linear_velocity", "snap", "floor_normal", "infinite_inertia", "stop_on_slope", "max_bounces", "floor_max_angle"), &KinematicBody2D::move_and_slide_with_snap, DEFVAL(Vector2(0, 0)), DEFVAL(true), DEFVAL(false), DEFVAL(4), DEFVAL(Math::deg2rad((float)45)));
 
 	ClassDB::bind_method(D_METHOD("test_move", "from", "rel_vec", "infinite_inertia"), &KinematicBody2D::test_move);
 

scene/2d/physics_body_2d.h

@@ -338,8 +338,8 @@ public:
 	void set_safe_margin(float p_margin);
 	float get_safe_margin() const;
 
-	Vector2 move_and_slide(const Vector2 &p_linear_velocity, const Vector2 &p_floor_direction = Vector2(0, 0), bool p_infinite_inertia = true, float p_slope_stop_min_velocity = 5, int p_max_slides = 4, float p_floor_max_angle = Math::deg2rad((float)45));
-	Vector2 move_and_slide_with_snap(const Vector2 &p_linear_velocity, const Vector2 &p_snap, const Vector2 &p_floor_direction = Vector2(0, 0), bool p_infinite_inertia = true, float p_slope_stop_min_velocity = 5, int p_max_slides = 4, float p_floor_max_angle = Math::deg2rad((float)45));
+	Vector2 move_and_slide(const Vector2 &p_linear_velocity, const Vector2 &p_floor_direction = Vector2(0, 0), bool p_infinite_inertia = true, bool p_stop_on_slope = false, int p_max_slides = 4, float p_floor_max_angle = Math::deg2rad((float)45));
+	Vector2 move_and_slide_with_snap(const Vector2 &p_linear_velocity, const Vector2 &p_snap, const Vector2 &p_floor_direction = Vector2(0, 0), bool p_infinite_inertia = true, bool p_stop_on_slope = false, int p_max_slides = 4, float p_floor_max_angle = Math::deg2rad((float)45));
 	bool is_on_floor() const;
 	bool is_on_wall() const;
 	bool is_on_ceiling() const;

scene/3d/physics_body.cpp

@@ -1078,10 +1078,10 @@ void RigidBody::_reload_physics_characteristics() {
 //////////////////////////////////////////////////////
 //////////////////////////
 
-Ref<KinematicCollision> KinematicBody::_move(const Vector3 &p_motion, bool p_infinite_inertia) {
+Ref<KinematicCollision> KinematicBody::_move(const Vector3 &p_motion, bool p_infinite_inertia, bool p_test_only) {
 
 	Collision col;
-	if (move_and_collide(p_motion, p_infinite_inertia, col)) {
+	if (move_and_collide(p_motion, p_infinite_inertia, col, p_test_only)) {
 		if (motion_cache.is_null()) {
 			motion_cache.instance();
 			motion_cache->owner = this;
@@ -1095,7 +1095,7 @@ Ref<KinematicCollision> KinematicBody::_move(const Vector3 &p_motion, bool p_inf
 	return Ref<KinematicCollision>();
 }
 
-bool KinematicBody::move_and_collide(const Vector3 &p_motion, bool p_infinite_inertia, Collision &r_collision) {
+bool KinematicBody::move_and_collide(const Vector3 &p_motion, bool p_infinite_inertia, Collision &r_collision, bool p_test_only) {
 
 	Transform gt = get_global_transform();
 	PhysicsServer::MotionResult result;
@@ -1108,6 +1108,7 @@ bool KinematicBody::move_and_collide(const Vector3 &p_motion, bool p_infinite_in
 		r_collision.collision = result.collision_point;
 		r_collision.normal = result.collision_normal;
 		r_collision.collider = result.collider_id;
+		r_collision.collider_rid = result.collider;
 		r_collision.travel = result.motion;
 		r_collision.remainder = result.remainder;
 		r_collision.local_shape = result.collision_local_shape;
@@ -1119,8 +1120,10 @@ bool KinematicBody::move_and_collide(const Vector3 &p_motion, bool p_infinite_in
 		}
 	}
 
-	gt.origin += result.motion;
-	set_global_transform(gt);
+	if (!p_test_only) {
+		gt.origin += result.motion;
+		set_global_transform(gt);
+	}
 
 	return colliding;
 }
@@ -1128,7 +1131,7 @@ bool KinematicBody::move_and_collide(const Vector3 &p_motion, bool p_infinite_in
 //so, if you pass 45 as limit, avoid numerical precision erros when angle is 45.
 #define FLOOR_ANGLE_THRESHOLD 0.01
 
-Vector3 KinematicBody::move_and_slide(const Vector3 &p_linear_velocity, const Vector3 &p_floor_direction, float p_slope_stop_min_velocity, int p_max_slides, float p_floor_max_angle, bool p_infinite_inertia) {
+Vector3 KinematicBody::move_and_slide(const Vector3 &p_linear_velocity, const Vector3 &p_floor_direction, bool p_stop_on_slope, int p_max_slides, float p_floor_max_angle, bool p_infinite_inertia) {
 
 	Vector3 lv = p_linear_velocity;
 
@@ -1146,69 +1149,127 @@ Vector3 KinematicBody::move_and_slide(const Vector3 &p_linear_velocity, const Ve
 	colliders.clear();
 	floor_velocity = Vector3();
 
+	Vector3 lv_n = p_linear_velocity.normalized();
+
 	while (p_max_slides) {
 
 		Collision collision;
 
-		bool collided = move_and_collide(motion, p_infinite_inertia, collision);
-
-		if (collided) {
+		bool found_collision = false;
 
-			motion = collision.remainder;
+		int test_type = 0;
 
-			if (p_floor_direction == Vector3()) {
-				//all is a wall
-				on_wall = true;
+		do {
+			bool collided;
+			if (test_type == 0) { //collide
+				collided = move_and_collide(motion, p_infinite_inertia, collision);
+				if (!collided) {
+					motion = Vector3(); //clear because no collision happened and motion completed
+				}
 			} else {
-				if (collision.normal.dot(p_floor_direction) >= Math::cos(p_floor_max_angle + FLOOR_ANGLE_THRESHOLD)) { //floor
+				collided = separate_raycast_shapes(p_infinite_inertia, collision);
+				if (collided) {
+					collision.remainder = motion; //keep
+					collision.travel = Vector3();
+				}
+			}
 
-					on_floor = true;
-					floor_velocity = collision.collider_vel;
+			if (collided) {
+				found_collision = true;
+			}
 
-					Vector3 rel_v = lv - floor_velocity;
-					Vector3 hv = rel_v - p_floor_direction * p_floor_direction.dot(rel_v);
+			if (collided) {
 
-					if (collision.travel.length() < 0.05 && hv.length() < p_slope_stop_min_velocity) {
-						Transform gt = get_global_transform();
-						gt.origin -= collision.travel;
-						set_global_transform(gt);
-						return floor_velocity - p_floor_direction * p_floor_direction.dot(floor_velocity);
-					}
-				} else if (collision.normal.dot(-p_floor_direction) >= Math::cos(p_floor_max_angle + FLOOR_ANGLE_THRESHOLD)) { //ceiling
-					on_ceiling = true;
-				} else {
+				colliders.push_back(collision);
+				motion = collision.remainder;
+
+				bool is_on_slope = false;
+				if (p_floor_direction == Vector3()) {
+					//all is a wall
 					on_wall = true;
+				} else {
+					if (collision.normal.dot(p_floor_direction) >= Math::cos(p_floor_max_angle + FLOOR_ANGLE_THRESHOLD)) { //floor
+
+						on_floor = true;
+						on_floor_body = collision.collider_rid;
+						floor_velocity = collision.collider_vel;
+
+						if (p_stop_on_slope) {
+							if (Vector3() == lv_n + p_floor_direction) {
+								Transform gt = get_global_transform();
+								gt.origin -= collision.travel;
+								set_global_transform(gt);
+								return Vector3();
+							}
+						}
+
+						is_on_slope = true;
+
+					} else if (collision.normal.dot(-p_floor_direction) >= Math::cos(p_floor_max_angle + FLOOR_ANGLE_THRESHOLD)) { //ceiling
+						on_ceiling = true;
+					} else {
+						on_wall = true;
+					}
 				}
-			}
 
-			Vector3 n = collision.normal;
-			motion = motion.slide(n);
-			lv = lv.slide(n);
+				if (p_stop_on_slope && is_on_slope) {
+					motion = motion.slide(p_floor_direction);
+					lv = lv.slide(p_floor_direction);
+				} else {
+					Vector3 n = collision.normal;
+					motion = motion.slide(n);
+					lv = lv.slide(n);
+				}
 
-			for (int i = 0; i < 3; i++) {
-				if (locked_axis & (1 << i)) {
-					lv[i] = 0;
+				for (int i = 0; i < 3; i++) {
+					if (locked_axis & (1 << i)) {
+						lv[i] = 0;
+					}
 				}
 			}
 
-			colliders.push_back(collision);
+			++test_type;
+		} while (!p_stop_on_slope && test_type < 2);
 
-		} else {
+		if (!found_collision || motion == Vector3())
 			break;
-		}
 
-		p_max_slides--;
-		if (motion == Vector3())
-			break;
+		--p_max_slides;
 	}
 
 	return lv;
 }
 
+Vector3 KinematicBody::move_and_slide_with_snap(const Vector3 &p_linear_velocity, const Vector3 &p_snap, const Vector3 &p_floor_direction, bool p_infinite_inertia, bool p_stop_on_slope, int p_max_slides, float p_floor_max_angle) {
+
+	bool was_on_floor = on_floor;
+
+	Vector3 ret = move_and_slide(p_linear_velocity, p_floor_direction, p_stop_on_slope, p_max_slides, p_floor_max_angle, p_infinite_inertia);
+	if (!was_on_floor || p_snap == Vector3()) {
+		return ret;
+	}
+
+	Collision col;
+	Transform gt = get_global_transform();
+
+	if (move_and_collide(p_snap, p_infinite_inertia, col, true)) {
+		gt.origin += col.travel;
+		if (p_floor_direction != Vector3() && Math::acos(p_floor_direction.normalized().dot(col.normal)) < p_floor_max_angle) {
+			on_floor = true;
+			on_floor_body = col.collider_rid;
+			floor_velocity = col.collider_vel;
+		}
+		set_global_transform(gt);
+	}
+
+	return ret;
+}
+
 bool KinematicBody::is_on_floor() const {
 
 	return on_floor;
 }
+
 bool KinematicBody::is_on_wall() const {
 
 	return on_wall;
@@ -1230,6 +1291,43 @@ bool KinematicBody::test_move(const Transform &p_from, const Vector3 &p_motion,
 	return PhysicsServer::get_singleton()->body_test_motion(get_rid(), p_from, p_motion, p_infinite_inertia);
 }
 
+bool KinematicBody::separate_raycast_shapes(bool p_infinite_inertia, Collision &r_collision) {
+
+	PhysicsServer::SeparationResult sep_res[8]; //max 8 rays
+
+	Transform gt = get_global_transform();
+
+	Vector3 recover;
+	int hits = PhysicsServer::get_singleton()->body_test_ray_separation(get_rid(), gt, p_infinite_inertia, recover, sep_res, 8, margin);
+	int deepest = -1;
+	float deepest_depth;
+	for (int i = 0; i < hits; i++) {
+		if (deepest == -1 || sep_res[i].collision_depth > deepest_depth) {
+			deepest = i;
+			deepest_depth = sep_res[i].collision_depth;
+		}
+	}
+
+	gt.origin += recover;
+	set_global_transform(gt);
+
+	if (deepest != -1) {
+		r_collision.collider = sep_res[deepest].collider_id;
+		r_collision.collider_metadata = sep_res[deepest].collider_metadata;
+		r_collision.collider_shape = sep_res[deepest].collider_shape;
+		r_collision.collider_vel = sep_res[deepest].collider_velocity;
+		r_collision.collision = sep_res[deepest].collision_point;
+		r_collision.normal = sep_res[deepest].collision_normal;
+		r_collision.local_shape = sep_res[deepest].collision_local_shape;
+		r_collision.travel = recover;
+		r_collision.remainder = Vector3();
+
+		return true;
+	} else {
+		return false;
+	}
+}
+
 void KinematicBody::set_axis_lock(PhysicsServer::BodyAxis p_axis, bool p_lock) {
 	PhysicsServer::get_singleton()->body_set_axis_lock(get_rid(), p_axis, p_lock);
 }
@@ -1276,8 +1374,9 @@ Ref<KinematicCollision> KinematicBody::_get_slide_collision(int p_bounce) {
 
 void KinematicBody::_bind_methods() {
 
-	ClassDB::bind_method(D_METHOD("move_and_collide", "rel_vec", "infinite_inertia"), &KinematicBody::_move, DEFVAL(true));
-	ClassDB::bind_method(D_METHOD("move_and_slide", "linear_velocity", "floor_normal", "slope_stop_min_velocity", "max_slides", "floor_max_angle", "infinite_inertia"), &KinematicBody::move_and_slide, DEFVAL(Vector3(0, 0, 0)), DEFVAL(0.05), DEFVAL(4), DEFVAL(Math::deg2rad((float)45)), DEFVAL(true));
+	ClassDB::bind_method(D_METHOD("move_and_collide", "rel_vec", "infinite_inertia", "test_only"), &KinematicBody::_move, DEFVAL(true), DEFVAL(false));
+	ClassDB::bind_method(D_METHOD("move_and_slide", "linear_velocity", "floor_normal", "stop_on_slope", "max_slides", "floor_max_angle", "infinite_inertia"), &KinematicBody::move_and_slide, DEFVAL(Vector3(0, 0, 0)), DEFVAL(false), DEFVAL(4), DEFVAL(Math::deg2rad((float)45)), DEFVAL(true));
+	ClassDB::bind_method(D_METHOD("move_and_slide_with_snap", "linear_velocity", "snap", "floor_normal", "infinite_inertia", "stop_on_slope", "max_bounces", "floor_max_angle"), &KinematicBody::move_and_slide_with_snap, DEFVAL(Vector3(0, 0, 0)), DEFVAL(true), DEFVAL(false), DEFVAL(4), DEFVAL(Math::deg2rad((float)45)));
 
 	ClassDB::bind_method(D_METHOD("test_move", "from", "rel_vec", "infinite_inertia"), &KinematicBody::test_move);
 

scene/3d/physics_body.h

@@ -285,6 +285,7 @@ public:
 		Vector3 normal;
 		Vector3 collider_vel;
 		ObjectID collider;
+		RID collider_rid;
 		int collider_shape;
 		Variant collider_metadata;
 		Vector3 remainder;
@@ -298,6 +299,7 @@ private:
 	float margin;
 
 	Vector3 floor_velocity;
+	RID on_floor_body;
 	bool on_floor;
 	bool on_ceiling;
 	bool on_wall;
@@ -307,23 +309,26 @@ private:
 
 	_FORCE_INLINE_ bool _ignores_mode(PhysicsServer::BodyMode) const;
 
-	Ref<KinematicCollision> _move(const Vector3 &p_motion, bool p_infinite_inertia = true);
+	Ref<KinematicCollision> _move(const Vector3 &p_motion, bool p_infinite_inertia = true, bool p_test_only = false);
 	Ref<KinematicCollision> _get_slide_collision(int p_bounce);
 
 protected:
 	static void _bind_methods();
 
 public:
-	bool move_and_collide(const Vector3 &p_motion, bool p_infinite_inertia, Collision &r_collisionz);
+	bool move_and_collide(const Vector3 &p_motion, bool p_infinite_inertia, Collision &r_collisionz, bool p_test_only = false);
 	bool test_move(const Transform &p_from, const Vector3 &p_motion, bool p_infinite_inertia);
 
+	bool separate_raycast_shapes(bool p_infinite_inertia, Collision &r_collision);
+
 	void set_axis_lock(PhysicsServer::BodyAxis p_axis, bool p_lock);
 	bool get_axis_lock(PhysicsServer::BodyAxis p_axis) const;
 
 	void set_safe_margin(float p_margin);
 	float get_safe_margin() const;
 
-	Vector3 move_and_slide(const Vector3 &p_linear_velocity, const Vector3 &p_floor_direction = Vector3(0, 0, 0), float p_slope_stop_min_velocity = 0.05, int p_max_slides = 4, float p_floor_max_angle = Math::deg2rad((float)45), bool p_infinite_inertia = true);
+	Vector3 move_and_slide(const Vector3 &p_linear_velocity, const Vector3 &p_floor_direction = Vector3(0, 0, 0), bool p_stop_on_slope = false, int p_max_slides = 4, float p_floor_max_angle = Math::deg2rad((float)45), bool p_infinite_inertia = true);
+	Vector3 move_and_slide_with_snap(const Vector3 &p_linear_velocity, const Vector3 &p_snap, const Vector3 &p_floor_direction = Vector3(0, 0, 0), bool p_infinite_inertia = true, bool p_stop_on_slope = false, int p_max_slides = 4, float p_floor_max_angle = Math::deg2rad((float)45));
 	bool is_on_floor() const;
 	bool is_on_wall() const;
 	bool is_on_ceiling() const;

servers/physics/physics_server_sw.h

@@ -231,6 +231,7 @@ public:
 	virtual bool body_is_ray_pickable(RID p_body) const;
 
 	virtual bool body_test_motion(RID p_body, const Transform &p_from, const Vector3 &p_motion, bool p_infinite_inertia, MotionResult *r_result = NULL);
+	virtual int body_test_ray_separation(RID p_body, const Transform &p_transform, bool p_infinite_inertia, Vector3 &r_recover_motion, SeparationResult *r_results, int p_result_max, float p_margin = 0.001) { return 0; }
 
 	// this function only works on physics process, errors and returns null otherwise
 	virtual PhysicsDirectBodyState *body_get_direct_state(RID p_body);

servers/physics_server.h

@@ -484,6 +484,21 @@ public:
 
 	virtual bool body_test_motion(RID p_body, const Transform &p_from, const Vector3 &p_motion, bool p_infinite_inertia, MotionResult *r_result = NULL) = 0;
 
+	struct SeparationResult {
+
+		float collision_depth;
+		Vector3 collision_point;
+		Vector3 collision_normal;
+		Vector3 collider_velocity;
+		int collision_local_shape;
+		ObjectID collider_id;
+		RID collider;
+		int collider_shape;
+		Variant collider_metadata;
+	};
+
+	virtual int body_test_ray_separation(RID p_body, const Transform &p_transform, bool p_infinite_inertia, Vector3 &r_recover_motion, SeparationResult *r_results, int p_result_max, float p_margin = 0.001) = 0;
+
 	/* SOFT BODY */
 
 	virtual RID soft_body_create(bool p_init_sleeping = false) = 0;