Remove Jolt Physics project setting "Areas Detect Static Bodies"

Author: mihe

doc/classes/ProjectSettings.xml

@@ -2607,12 +2607,6 @@
 		<member name="physics/jolt_physics_3d/simulation/allow_sleep" type="bool" setter="" getter="" default="true">
 			If [code]true[/code], [RigidBody3D] nodes are allowed to go to sleep if their velocity is below the threshold defined in [member physics/jolt_physics_3d/simulation/sleep_velocity_threshold] for the duration set in [member physics/jolt_physics_3d/simulation/sleep_time_threshold]. This can improve physics simulation performance when there are non-moving [RigidBody3D] nodes, at the cost of some nodes possibly failing to wake up in certain scenarios. Consider disabling this temporarily to troubleshoot [RigidBody3D] nodes not moving when they should.
 		</member>
-		<member name="physics/jolt_physics_3d/simulation/areas_detect_static_bodies" type="bool" setter="" getter="" default="false">
-			If [code]true[/code], [Area3D] nodes are able to detect overlaps with [StaticBody3D] nodes.
-			[b]Note:[/b] Enabling this setting can come at a heavy CPU and memory cost if you allow many/large [Area3D] to overlap with complex static geometry, such as [ConcavePolygonShape3D] or [HeightMapShape3D]. It is strongly recommended that you set up your collision layers and masks in such a way that only a few small [Area3D] nodes can detect [StaticBody3D] nodes.
-			[b]Note:[/b] This also applies to overlaps with a [RigidBody3D] frozen with [constant RigidBody3D.FREEZE_MODE_STATIC].
-			[b]Note:[/b] This is not needed to detect overlaps with [AnimatableBody3D], as it is a kinematic body, despite inheriting from [StaticBody3D].
-		</member>
 		<member name="physics/jolt_physics_3d/simulation/baumgarte_stabilization_factor" type="float" setter="" getter="" default="0.2">
 			How much of the position error of a [RigidBody3D] to fix during a physics step, where [code]0.0[/code] is none and [code]1.0[/code] is the full amount. This affects things like how quickly bodies depenetrate.
 			[b]Note:[/b] Setting this value too high can make [RigidBody3D] nodes unstable.

modules/jolt_physics/jolt_project_settings.cpp

@@ -36,7 +36,6 @@ void JoltProjectSettings::register_settings() {
 	GLOBAL_DEF(PropertyInfo(Variant::INT, "physics/jolt_physics_3d/simulation/velocity_steps", PROPERTY_HINT_RANGE, U"2,16,or_greater"), 10);
 	GLOBAL_DEF(PropertyInfo(Variant::INT, "physics/jolt_physics_3d/simulation/position_steps", PROPERTY_HINT_RANGE, U"1,16,or_greater"), 2);
 	GLOBAL_DEF(PropertyInfo(Variant::BOOL, "physics/jolt_physics_3d/simulation/use_enhanced_internal_edge_removal"), true);
-	GLOBAL_DEF(PropertyInfo(Variant::BOOL, "physics/jolt_physics_3d/simulation/areas_detect_static_bodies"), false);
 	GLOBAL_DEF(PropertyInfo(Variant::BOOL, "physics/jolt_physics_3d/simulation/generate_all_kinematic_contacts"), false);
 	GLOBAL_DEF(PropertyInfo(Variant::FLOAT, "physics/jolt_physics_3d/simulation/penetration_slop", PROPERTY_HINT_RANGE, U"0,1,0.00001,or_greater,suffix:m"), 0.02f);
 	GLOBAL_DEF(PropertyInfo(Variant::FLOAT, "physics/jolt_physics_3d/simulation/speculative_contact_distance", PROPERTY_HINT_RANGE, U"0,1,0.00001,or_greater,suffix:m"), 0.02f);
@@ -81,7 +80,6 @@ void JoltProjectSettings::read_settings() {
 	simulation_velocity_steps = GLOBAL_GET("physics/jolt_physics_3d/simulation/velocity_steps");
 	simulation_position_steps = GLOBAL_GET("physics/jolt_physics_3d/simulation/position_steps");
 	use_enhanced_internal_edge_removal_for_bodies = GLOBAL_GET("physics/jolt_physics_3d/simulation/use_enhanced_internal_edge_removal");
-	areas_detect_static_bodies = GLOBAL_GET("physics/jolt_physics_3d/simulation/areas_detect_static_bodies");
 	generate_all_kinematic_contacts = GLOBAL_GET("physics/jolt_physics_3d/simulation/generate_all_kinematic_contacts");
 	penetration_slop = GLOBAL_GET("physics/jolt_physics_3d/simulation/penetration_slop");
 	speculative_contact_distance = GLOBAL_GET("physics/jolt_physics_3d/simulation/speculative_contact_distance");

modules/jolt_physics/jolt_project_settings.h

@@ -42,7 +42,6 @@ class JoltProjectSettings {
 	inline static int simulation_velocity_steps;
 	inline static int simulation_position_steps;
 	inline static bool use_enhanced_internal_edge_removal_for_bodies;
-	inline static bool areas_detect_static_bodies;
 	inline static bool generate_all_kinematic_contacts;
 	inline static float penetration_slop;
 	inline static float speculative_contact_distance;

modules/jolt_physics/objects/jolt_area_3d.cpp

@@ -72,15 +72,12 @@ void JoltArea3D::_add_to_space() {
 	jolt_settings->mCollisionGroup = JPH::CollisionGroup(nullptr, group_id, sub_group_id);
 	jolt_settings->mMotionType = _get_motion_type();
 	jolt_settings->mIsSensor = true;
+	jolt_settings->mCollideKinematicVsNonDynamic = true;
 	jolt_settings->mUseManifoldReduction = false;
 	jolt_settings->mOverrideMassProperties = JPH::EOverrideMassProperties::MassAndInertiaProvided;
 	jolt_settings->mMassPropertiesOverride.mMass = 1.0f;
 	jolt_settings->mMassPropertiesOverride.mInertia = JPH::Mat44::sIdentity();
 
-	if (JoltProjectSettings::areas_detect_static_bodies) {
-		jolt_settings->mCollideKinematicVsNonDynamic = true;
-	}
-
 	jolt_settings->SetShape(jolt_shape);
 
 	JPH::Body *new_jolt_body = space->add_rigid_body(*this, *jolt_settings, _should_sleep());

modules/jolt_physics/spaces/jolt_layers.cpp

@@ -52,28 +52,25 @@ class JoltBroadPhaseMatrix {
 		using namespace JoltBroadPhaseLayer;
 
 		allow_collision(BODY_STATIC, BODY_DYNAMIC);
+		allow_collision(BODY_STATIC, AREA_DETECTABLE);
+		allow_collision(BODY_STATIC, AREA_UNDETECTABLE);
 		allow_collision(BODY_STATIC_BIG, BODY_DYNAMIC);
+		allow_collision(BODY_STATIC_BIG, AREA_DETECTABLE);
+		allow_collision(BODY_STATIC_BIG, AREA_UNDETECTABLE);
 		allow_collision(BODY_DYNAMIC, BODY_STATIC);
 		allow_collision(BODY_DYNAMIC, BODY_STATIC_BIG);
 		allow_collision(BODY_DYNAMIC, BODY_DYNAMIC);
 		allow_collision(BODY_DYNAMIC, AREA_DETECTABLE);
 		allow_collision(BODY_DYNAMIC, AREA_UNDETECTABLE);
 		allow_collision(AREA_DETECTABLE, BODY_DYNAMIC);
+		allow_collision(AREA_DETECTABLE, BODY_STATIC);
+		allow_collision(AREA_DETECTABLE, BODY_STATIC_BIG);
 		allow_collision(AREA_DETECTABLE, AREA_DETECTABLE);
 		allow_collision(AREA_DETECTABLE, AREA_UNDETECTABLE);
 		allow_collision(AREA_UNDETECTABLE, BODY_DYNAMIC);
+		allow_collision(AREA_UNDETECTABLE, BODY_STATIC);
+		allow_collision(AREA_UNDETECTABLE, BODY_STATIC_BIG);
 		allow_collision(AREA_UNDETECTABLE, AREA_DETECTABLE);
-
-		if (JoltProjectSettings::areas_detect_static_bodies) {
-			allow_collision(BODY_STATIC, AREA_DETECTABLE);
-			allow_collision(BODY_STATIC, AREA_UNDETECTABLE);
-			allow_collision(BODY_STATIC_BIG, AREA_DETECTABLE);
-			allow_collision(BODY_STATIC_BIG, AREA_UNDETECTABLE);
-			allow_collision(AREA_DETECTABLE, BODY_STATIC);
-			allow_collision(AREA_DETECTABLE, BODY_STATIC_BIG);
-			allow_collision(AREA_UNDETECTABLE, BODY_STATIC);
-			allow_collision(AREA_UNDETECTABLE, BODY_STATIC_BIG);
-		}
 	}
 
 	void allow_collision(UnderlyingType p_layer1, UnderlyingType p_layer2) { masks[p_layer1] |= uint8_t(1U << p_layer2); }

modules/jolt_physics/spaces/jolt_space_3d.cpp

@@ -48,6 +48,8 @@
 #include "core/string/print_string.h"
 #include "core/variant/variant_utility.h"
 
+#include "Jolt/Physics/Collision/CollideShapeVsShapePerLeaf.h"
+#include "Jolt/Physics/Collision/CollisionCollectorImpl.h"
 #include "Jolt/Physics/PhysicsScene.h"
 
 namespace {
@@ -121,6 +123,18 @@ JoltSpace3D::JoltSpace3D(JPH::JobSystem *p_job_system) :
 	physics_system->SetContactListener(contact_listener);
 	physics_system->SetSoftBodyContactListener(contact_listener);
 
+	physics_system->SetSimCollideBodyVsBody([](const JPH::Body &p_body1, const JPH::Body &p_body2, JPH::Mat44Arg p_transform_com1, JPH::Mat44Arg p_transform_com2, JPH::CollideShapeSettings &p_collide_shape_settings, JPH::CollideShapeCollector &p_collector, const JPH::ShapeFilter &p_shape_filter) {
+		if (p_body1.IsSensor() || p_body2.IsSensor()) {
+			JPH::CollideShapeSettings new_collide_shape_settings = p_collide_shape_settings;
+			// Since we're breaking the sensor down into leaf shapes we'll end up stripping away our `JoltCustomDoubleSidedShape` decorator shape and thus any back-face collision, so we simply force-enable it like this rather than going through the trouble of reapplying the decorator.
+			new_collide_shape_settings.mBackFaceMode = JPH::EBackFaceMode::CollideWithBackFaces;
+			JPH::SubShapeIDCreator part1, part2;
+			JPH::CollideShapeVsShapePerLeaf<JPH::AnyHitCollisionCollector<JPH::CollideShapeCollector>>(p_body1.GetShape(), p_body2.GetShape(), JPH::Vec3::sOne(), JPH::Vec3::sOne(), p_transform_com1, p_transform_com2, part1, part2, new_collide_shape_settings, p_collector, p_shape_filter);
+		} else {
+			JPH::PhysicsSystem::sDefaultSimCollideBodyVsBody(p_body1, p_body2, p_transform_com1, p_transform_com2, p_collide_shape_settings, p_collector, p_shape_filter);
+		}
+	});
+
 	physics_system->SetCombineFriction([](const JPH::Body &p_body1, const JPH::SubShapeID &p_sub_shape_id1, const JPH::Body &p_body2, const JPH::SubShapeID &p_sub_shape_id2) {
 		return Math::abs(MIN(p_body1.GetFriction(), p_body2.GetFriction()));
 	});