Expose bullet shape margin to UI.

The margin value is exposed into the UI for shape ressource.
This value can be modified through set_margin and get from get_margin
or by using the property margin. Each time the margin is modified
the associated collision shape is recreated and the margin value is
used in ShapeBullet::prepare.

9 files changed, 98 insertions, 31 deletions

diff --git a/modules/bullet/bullet_physics_server.cpp b/modules/bullet/bullet_physics_server.cpp
index 6246a295ec..e767988593 100644
--- a/modules/bullet/bullet_physics_server.cpp
+++ b/modules/bullet/bullet_physics_server.cpp
@@ -159,6 +159,18 @@ Variant BulletPhysicsServer::shape_get_data(RID p_shape) const {
 	return shape->get_data();
 }
 
+void BulletPhysicsServer::shape_set_margin(RID p_shape, real_t p_margin) {
+	ShapeBullet *shape = shape_owner.get(p_shape);
+	ERR_FAIL_COND(!shape);
+	shape->set_margin(p_margin);
+}
+
+real_t BulletPhysicsServer::shape_get_margin(RID p_shape) const {
+	ShapeBullet *shape = shape_owner.get(p_shape);
+	ERR_FAIL_COND_V(!shape, 0.0);
+	return shape->get_margin();
+}
+
 real_t BulletPhysicsServer::shape_get_custom_solver_bias(RID p_shape) const {
 	//WARN_PRINT("Bias not supported by Bullet physics engine");
 	return 0.;
diff --git a/modules/bullet/bullet_physics_server.h b/modules/bullet/bullet_physics_server.h
index e931915bba..97d5c140c5 100644
--- a/modules/bullet/bullet_physics_server.h
+++ b/modules/bullet/bullet_physics_server.h
@@ -99,6 +99,9 @@ public:
 	virtual ShapeType shape_get_type(RID p_shape) const;
 	virtual Variant shape_get_data(RID p_shape) const;
 
+	virtual void shape_set_margin(RID p_shape, real_t p_margin);
+	virtual real_t shape_get_margin(RID p_shape) const;
+
 	/// Not supported
 	virtual void shape_set_custom_solver_bias(RID p_shape, real_t p_bias);
 	/// Not supported
diff --git a/modules/bullet/shape_bullet.cpp b/modules/bullet/shape_bullet.cpp
index 76d9614465..cc865bb5be 100644
--- a/modules/bullet/shape_bullet.cpp
+++ b/modules/bullet/shape_bullet.cpp
@@ -44,19 +44,20 @@
 	@author AndreaCatania
 */
 
-ShapeBullet::ShapeBullet() {}
+ShapeBullet::ShapeBullet() :
+		margin(0.04) {}
 
 ShapeBullet::~ShapeBullet() {}
 
-btCollisionShape *ShapeBullet::create_bt_shape(const Vector3 &p_implicit_scale, real_t p_margin) {
+btCollisionShape *ShapeBullet::create_bt_shape(const Vector3 &p_implicit_scale, real_t p_extra_edge) {
 	btVector3 s;
 	G_TO_B(p_implicit_scale, s);
-	return create_bt_shape(s, p_margin);
+	return create_bt_shape(s, p_extra_edge);
 }
 
 btCollisionShape *ShapeBullet::prepare(btCollisionShape *p_btShape) const {
 	p_btShape->setUserPointer(const_cast<ShapeBullet *>(this));
-	p_btShape->setMargin(0.);
+	p_btShape->setMargin(margin);
 	return p_btShape;
 }
 
@@ -93,6 +94,15 @@ const Map<ShapeOwnerBullet *, int> &ShapeBullet::get_owners() const {
 	return owners;
 }
 
+void ShapeBullet::set_margin(real_t p_margin) {
+	margin = p_margin;
+	notifyShapeChanged();
+}
+
+real_t ShapeBullet::get_margin() const {
+	return margin;
+}
+
 btEmptyShape *ShapeBullet::create_shape_empty() {
 	return bulletnew(btEmptyShape);
 }
@@ -162,7 +172,7 @@ void PlaneShapeBullet::setup(const Plane &p_plane) {
 	notifyShapeChanged();
 }
 
-btCollisionShape *PlaneShapeBullet::create_bt_shape(const btVector3 &p_implicit_scale, real_t p_margin) {
+btCollisionShape *PlaneShapeBullet::create_bt_shape(const btVector3 &p_implicit_scale, real_t p_extra_edge) {
 	btVector3 btPlaneNormal;
 	G_TO_B(plane.normal, btPlaneNormal);
 	return prepare(PlaneShapeBullet::create_shape_plane(btPlaneNormal, plane.d));
@@ -190,8 +200,8 @@ void SphereShapeBullet::setup(real_t p_radius) {
 	notifyShapeChanged();
 }
 
-btCollisionShape *SphereShapeBullet::create_bt_shape(const btVector3 &p_implicit_scale, real_t p_margin) {
-	return prepare(ShapeBullet::create_shape_sphere(radius * p_implicit_scale[0] + p_margin));
+btCollisionShape *SphereShapeBullet::create_bt_shape(const btVector3 &p_implicit_scale, real_t p_extra_edge) {
+	return prepare(ShapeBullet::create_shape_sphere(radius * p_implicit_scale[0] + p_extra_edge));
 }
 
 /* Box */
@@ -217,8 +227,8 @@ void BoxShapeBullet::setup(const Vector3 &p_half_extents) {
 	notifyShapeChanged();
 }
 
-btCollisionShape *BoxShapeBullet::create_bt_shape(const btVector3 &p_implicit_scale, real_t p_margin) {
-	return prepare(ShapeBullet::create_shape_box((half_extents * p_implicit_scale) + btVector3(p_margin, p_margin, p_margin)));
+btCollisionShape *BoxShapeBullet::create_bt_shape(const btVector3 &p_implicit_scale, real_t p_extra_edge) {
+	return prepare(ShapeBullet::create_shape_box((half_extents * p_implicit_scale) + btVector3(p_extra_edge, p_extra_edge, p_extra_edge)));
 }
 
 /* Capsule */
@@ -250,8 +260,8 @@ void CapsuleShapeBullet::setup(real_t p_height, real_t p_radius) {
 	notifyShapeChanged();
 }
 
-btCollisionShape *CapsuleShapeBullet::create_bt_shape(const btVector3 &p_implicit_scale, real_t p_margin) {
-	return prepare(ShapeBullet::create_shape_capsule(radius * p_implicit_scale[0] + p_margin, height * p_implicit_scale[1] + p_margin));
+btCollisionShape *CapsuleShapeBullet::create_bt_shape(const btVector3 &p_implicit_scale, real_t p_extra_edge) {
+	return prepare(ShapeBullet::create_shape_capsule(radius * p_implicit_scale[0] + p_extra_edge, height * p_implicit_scale[1] + p_extra_edge));
 }
 
 /* Convex polygon */
@@ -292,11 +302,10 @@ void ConvexPolygonShapeBullet::setup(const Vector<Vector3> &p_vertices) {
 	notifyShapeChanged();
 }
 
-btCollisionShape *ConvexPolygonShapeBullet::create_bt_shape(const btVector3 &p_implicit_scale, real_t p_margin) {
+btCollisionShape *ConvexPolygonShapeBullet::create_bt_shape(const btVector3 &p_implicit_scale, real_t p_extra_edge) {
 	btCollisionShape *cs(ShapeBullet::create_shape_convex(vertices));
 	cs->setLocalScaling(p_implicit_scale);
 	prepare(cs);
-	cs->setMargin(p_margin);
 	return cs;
 }
 
@@ -365,14 +374,13 @@ void ConcavePolygonShapeBullet::setup(PoolVector<Vector3> p_faces) {
 	notifyShapeChanged();
 }
 
-btCollisionShape *ConcavePolygonShapeBullet::create_bt_shape(const btVector3 &p_implicit_scale, real_t p_margin) {
+btCollisionShape *ConcavePolygonShapeBullet::create_bt_shape(const btVector3 &p_implicit_scale, real_t p_extra_edge) {
 	btCollisionShape *cs = ShapeBullet::create_shape_concave(meshShape);
 	if (!cs)
 		// This is necessary since if 0 faces the creation of concave return NULL
 		cs = ShapeBullet::create_shape_empty();
 	cs->setLocalScaling(p_implicit_scale);
 	prepare(cs);
-	cs->setMargin(p_margin);
 	return cs;
 }
 
@@ -458,11 +466,10 @@ void HeightMapShapeBullet::setup(PoolVector<real_t> &p_heights, int p_width, int
 	notifyShapeChanged();
 }
 
-btCollisionShape *HeightMapShapeBullet::create_bt_shape(const btVector3 &p_implicit_scale, real_t p_margin) {
+btCollisionShape *HeightMapShapeBullet::create_bt_shape(const btVector3 &p_implicit_scale, real_t p_extra_edge) {
 	btCollisionShape *cs(ShapeBullet::create_shape_height_field(heights, width, depth, min_height, max_height));
 	cs->setLocalScaling(p_implicit_scale);
 	prepare(cs);
-	cs->setMargin(p_margin);
 	return cs;
 }
 
@@ -496,6 +503,6 @@ void RayShapeBullet::setup(real_t p_length, bool p_slips_on_slope) {
 	notifyShapeChanged();
 }
 
-btCollisionShape *RayShapeBullet::create_bt_shape(const btVector3 &p_implicit_scale, real_t p_margin) {
-	return prepare(ShapeBullet::create_shape_ray(length * p_implicit_scale[1] + p_margin, slips_on_slope));
+btCollisionShape *RayShapeBullet::create_bt_shape(const btVector3 &p_implicit_scale, real_t p_extra_edge) {
+	return prepare(ShapeBullet::create_shape_ray(length * p_implicit_scale[1] + p_extra_edge, slips_on_slope));
 }
diff --git a/modules/bullet/shape_bullet.h b/modules/bullet/shape_bullet.h
index abeea0f9ce..ac20008262 100644
--- a/modules/bullet/shape_bullet.h
+++ b/modules/bullet/shape_bullet.h
@@ -52,6 +52,7 @@ class btBvhTriangleMeshShape;
 class ShapeBullet : public RIDBullet {
 
 	Map<ShapeOwnerBullet *, int> owners;
+	real_t margin;
 
 protected:
 	/// return self
@@ -62,14 +63,17 @@ public:
 	ShapeBullet();
 	virtual ~ShapeBullet();
 
-	btCollisionShape *create_bt_shape(const Vector3 &p_implicit_scale, real_t p_margin = 0);
-	virtual btCollisionShape *create_bt_shape(const btVector3 &p_implicit_scale, real_t p_margin = 0) = 0;
+	btCollisionShape *create_bt_shape(const Vector3 &p_implicit_scale, real_t p_extra_edge = 0);
+	virtual btCollisionShape *create_bt_shape(const btVector3 &p_implicit_scale, real_t p_extra_edge = 0) = 0;
 
 	void add_owner(ShapeOwnerBullet *p_owner);
 	void remove_owner(ShapeOwnerBullet *p_owner, bool p_permanentlyFromThisBody = false);
 	bool is_owner(ShapeOwnerBullet *p_owner) const;
 	const Map<ShapeOwnerBullet *, int> &get_owners() const;
 
+	void set_margin(real_t p_margin);
+	real_t get_margin() const;
+
 	/// Setup the shape
 	virtual void set_data(const Variant &p_data) = 0;
 	virtual Variant get_data() const = 0;
@@ -99,7 +103,7 @@ public:
 	virtual void set_data(const Variant &p_data);
 	virtual Variant get_data() const;
 	virtual PhysicsServer::ShapeType get_type() const;
-	virtual btCollisionShape *create_bt_shape(const btVector3 &p_implicit_scale, real_t p_margin = 0);
+	virtual btCollisionShape *create_bt_shape(const btVector3 &p_implicit_scale, real_t p_extra_edge = 0);
 
 private:
 	void setup(const Plane &p_plane);
@@ -116,7 +120,7 @@ public:
 	virtual void set_data(const Variant &p_data);
 	virtual Variant get_data() const;
 	virtual PhysicsServer::ShapeType get_type() const;
-	virtual btCollisionShape *create_bt_shape(const btVector3 &p_implicit_scale, real_t p_margin = 0);
+	virtual btCollisionShape *create_bt_shape(const btVector3 &p_implicit_scale, real_t p_extra_edge = 0);
 
 private:
 	void setup(real_t p_radius);
@@ -133,7 +137,7 @@ public:
 	virtual void set_data(const Variant &p_data);
 	virtual Variant get_data() const;
 	virtual PhysicsServer::ShapeType get_type() const;
-	virtual btCollisionShape *create_bt_shape(const btVector3 &p_implicit_scale, real_t p_margin = 0);
+	virtual btCollisionShape *create_bt_shape(const btVector3 &p_implicit_scale, real_t p_extra_edge = 0);
 
 private:
 	void setup(const Vector3 &p_half_extents);
@@ -152,7 +156,7 @@ public:
 	virtual void set_data(const Variant &p_data);
 	virtual Variant get_data() const;
 	virtual PhysicsServer::ShapeType get_type() const;
-	virtual btCollisionShape *create_bt_shape(const btVector3 &p_implicit_scale, real_t p_margin = 0);
+	virtual btCollisionShape *create_bt_shape(const btVector3 &p_implicit_scale, real_t p_extra_edge = 0);
 
 private:
 	void setup(real_t p_height, real_t p_radius);
@@ -169,7 +173,7 @@ public:
 	void get_vertices(Vector<Vector3> &out_vertices);
 	virtual Variant get_data() const;
 	virtual PhysicsServer::ShapeType get_type() const;
-	virtual btCollisionShape *create_bt_shape(const btVector3 &p_implicit_scale, real_t p_margin = 0);
+	virtual btCollisionShape *create_bt_shape(const btVector3 &p_implicit_scale, real_t p_extra_edge = 0);
 
 private:
 	void setup(const Vector<Vector3> &p_vertices);
@@ -187,7 +191,7 @@ public:
 	virtual void set_data(const Variant &p_data);
 	virtual Variant get_data() const;
 	virtual PhysicsServer::ShapeType get_type() const;
-	virtual btCollisionShape *create_bt_shape(const btVector3 &p_implicit_scale, real_t p_margin = 0);
+	virtual btCollisionShape *create_bt_shape(const btVector3 &p_implicit_scale, real_t p_extra_edge = 0);
 
 private:
 	void setup(PoolVector<Vector3> p_faces);
@@ -207,7 +211,7 @@ public:
 	virtual void set_data(const Variant &p_data);
 	virtual Variant get_data() const;
 	virtual PhysicsServer::ShapeType get_type() const;
-	virtual btCollisionShape *create_bt_shape(const btVector3 &p_implicit_scale, real_t p_margin = 0);
+	virtual btCollisionShape *create_bt_shape(const btVector3 &p_implicit_scale, real_t p_extra_edge = 0);
 
 private:
 	void setup(PoolVector<real_t> &p_heights, int p_width, int p_depth, real_t p_min_height, real_t p_max_height);
@@ -224,7 +228,7 @@ public:
 	virtual void set_data(const Variant &p_data);
 	virtual Variant get_data() const;
 	virtual PhysicsServer::ShapeType get_type() const;
-	virtual btCollisionShape *create_bt_shape(const btVector3 &p_implicit_scale, real_t p_margin = 0);
+	virtual btCollisionShape *create_bt_shape(const btVector3 &p_implicit_scale, real_t p_extra_edge = 0);
 
 private:
 	void setup(real_t p_length, bool p_slips_on_slope);
diff --git a/scene/resources/shape.cpp b/scene/resources/shape.cpp
index 418d8ce819..a48ce0564b 100644
--- a/scene/resources/shape.cpp
+++ b/scene/resources/shape.cpp
@@ -50,6 +50,15 @@ void Shape::add_vertices_to_array(PoolVector<Vector3> &array, const Transform &p
 	}
 }
 
+real_t Shape::get_margin() const {
+	return margin;
+}
+
+void Shape::set_margin(real_t p_margin) {
+	margin = p_margin;
+	PhysicsServer::get_singleton()->shape_set_margin(shape, margin);
+}
+
 Ref<ArrayMesh> Shape::get_debug_mesh() {
 
 	if (debug_mesh_cache.is_valid())
@@ -87,12 +96,22 @@ Ref<ArrayMesh> Shape::get_debug_mesh() {
 	return debug_mesh_cache;
 }
 
-Shape::Shape() {
+void Shape::_bind_methods() {
+
+	ClassDB::bind_method(D_METHOD("set_margin", "margin"), &Shape::set_margin);
+	ClassDB::bind_method(D_METHOD("get_margin"), &Shape::get_margin);
+
+	ADD_PROPERTY(PropertyInfo(Variant::REAL, "margin", PROPERTY_HINT_RANGE, "0.04,10,0.01"), "set_margin", "get_margin");
+}
+
+Shape::Shape() :
+		margin(0.04) {
 
 	ERR_PRINT("Constructor must not be called!");
 }
 
-Shape::Shape(RID p_shape) {
+Shape::Shape(RID p_shape) :
+		margin(0.04) {
 
 	shape = p_shape;
 }
diff --git a/scene/resources/shape.h b/scene/resources/shape.h
index ad87a69679..0c44b86e92 100644
--- a/scene/resources/shape.h
+++ b/scene/resources/shape.h
@@ -40,10 +40,13 @@ class Shape : public Resource {
 	OBJ_SAVE_TYPE(Shape);
 	RES_BASE_EXTENSION("shape");
 	RID shape;
+	real_t margin;
 
 	Ref<ArrayMesh> debug_mesh_cache;
 
 protected:
+	static void _bind_methods();
+
 	_FORCE_INLINE_ RID get_shape() const { return shape; }
 	Shape(RID p_shape);
 
@@ -55,6 +58,9 @@ public:
 
 	void add_vertices_to_array(PoolVector<Vector3> &array, const Transform &p_xform);
 
+	real_t get_margin() const;
+	void set_margin(real_t p_margin);
+
 	Shape();
 	~Shape();
 };
diff --git a/servers/physics/physics_server_sw.cpp b/servers/physics/physics_server_sw.cpp
index f2dbb635f8..7a2d773944 100644
--- a/servers/physics/physics_server_sw.cpp
+++ b/servers/physics/physics_server_sw.cpp
@@ -119,6 +119,13 @@ Variant PhysicsServerSW::shape_get_data(RID p_shape) const {
 	return shape->get_data();
 };
 
+void PhysicsServerSW::shape_set_margin(RID p_shape, real_t p_margin) {
+}
+
+real_t PhysicsServerSW::shape_get_margin(RID p_shape) const {
+	return 0.0;
+}
+
 real_t PhysicsServerSW::shape_get_custom_solver_bias(RID p_shape) const {
 
 	const ShapeSW *shape = shape_owner.get(p_shape);
@@ -287,6 +294,7 @@ void PhysicsServerSW::area_set_shape(RID p_area, int p_shape_idx, RID p_shape) {
 
 	area->set_shape(p_shape_idx, shape);
 }
+
 void PhysicsServerSW::area_set_shape_transform(RID p_area, int p_shape_idx, const Transform &p_transform) {
 
 	AreaSW *area = area_owner.get(p_area);
diff --git a/servers/physics/physics_server_sw.h b/servers/physics/physics_server_sw.h
index 3f56ba26d0..c2a4744757 100644
--- a/servers/physics/physics_server_sw.h
+++ b/servers/physics/physics_server_sw.h
@@ -85,6 +85,10 @@ public:
 
 	virtual ShapeType shape_get_type(RID p_shape) const;
 	virtual Variant shape_get_data(RID p_shape) const;
+
+	virtual void shape_set_margin(RID p_shape, real_t p_margin);
+	virtual real_t shape_get_margin(RID p_shape) const;
+
 	virtual real_t shape_get_custom_solver_bias(RID p_shape) const;
 
 	/* SPACE API */
diff --git a/servers/physics_server.h b/servers/physics_server.h
index 6712bee8dc..f8e7e694f6 100644
--- a/servers/physics_server.h
+++ b/servers/physics_server.h
@@ -240,6 +240,10 @@ public:
 
 	virtual ShapeType shape_get_type(RID p_shape) const = 0;
 	virtual Variant shape_get_data(RID p_shape) const = 0;
+
+	virtual void shape_set_margin(RID p_shape, real_t p_margin) = 0;
+	virtual real_t shape_get_margin(RID p_shape) const = 0;
+
 	virtual real_t shape_get_custom_solver_bias(RID p_shape) const = 0;
 
 	/* SPACE API */