Add raycast options to hit when starting inside / hit back faces

Makes the results consistent for all shape types with options to set
the desired behavior.

7 files changed, 59 insertions, 43 deletions

diff --git a/servers/physics_3d/godot_body_pair_3d.cpp b/servers/physics_3d/godot_body_pair_3d.cpp
index f7d9ed9ee9..f0002870ae 100644
--- a/servers/physics_3d/godot_body_pair_3d.cpp
+++ b/servers/physics_3d/godot_body_pair_3d.cpp
@@ -191,7 +191,7 @@ bool GodotBodyPair3D::_test_ccd(real_t p_step, GodotBody3D *p_A, int p_shape_A,
 	Vector3 local_to = from_inv.xform(to);
 
 	Vector3 rpos, rnorm;
-	if (!p_B->get_shape(p_shape_B)->intersect_segment(local_from, local_to, rpos, rnorm)) {
+	if (!p_B->get_shape(p_shape_B)->intersect_segment(local_from, local_to, rpos, rnorm, true)) {
 		return false;
 	}
 
diff --git a/servers/physics_3d/godot_collision_solver_3d.cpp b/servers/physics_3d/godot_collision_solver_3d.cpp
index b9f2f7506b..686f3e4d59 100644
--- a/servers/physics_3d/godot_collision_solver_3d.cpp
+++ b/servers/physics_3d/godot_collision_solver_3d.cpp
@@ -102,7 +102,7 @@ bool GodotCollisionSolver3D::solve_separation_ray(const GodotShape3D *p_shape_A,
 	to = ai.xform(to);
 
 	Vector3 p, n;
-	if (!p_shape_B->intersect_segment(from, to, p, n)) {
+	if (!p_shape_B->intersect_segment(from, to, p, n, true)) {
 		return false;
 	}
 
diff --git a/servers/physics_3d/godot_shape_3d.cpp b/servers/physics_3d/godot_shape_3d.cpp
index 4c12a5a948..b520ee45c7 100644
--- a/servers/physics_3d/godot_shape_3d.cpp
+++ b/servers/physics_3d/godot_shape_3d.cpp
@@ -119,7 +119,7 @@ Vector3 GodotWorldBoundaryShape3D::get_support(const Vector3 &p_normal) const {
 	return p_normal * 1e15;
 }
 
-bool GodotWorldBoundaryShape3D::intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal) const {
+bool GodotWorldBoundaryShape3D::intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal, bool p_hit_back_faces) const {
 	bool inters = plane.intersects_segment(p_begin, p_end, &r_result);
 	if (inters) {
 		r_normal = plane.normal;
@@ -200,7 +200,7 @@ void GodotSeparationRayShape3D::get_supports(const Vector3 &p_normal, int p_max,
 	}
 }
 
-bool GodotSeparationRayShape3D::intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal) const {
+bool GodotSeparationRayShape3D::intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal, bool p_hit_back_faces) const {
 	return false; //simply not possible
 }
 
@@ -268,7 +268,7 @@ void GodotSphereShape3D::get_supports(const Vector3 &p_normal, int p_max, Vector
 	r_type = FEATURE_POINT;
 }
 
-bool GodotSphereShape3D::intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal) const {
+bool GodotSphereShape3D::intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal, bool p_hit_back_faces) const {
 	return Geometry3D::segment_intersects_sphere(p_begin, p_end, Vector3(), radius, &r_result, &r_normal);
 }
 
@@ -410,7 +410,7 @@ void GodotBoxShape3D::get_supports(const Vector3 &p_normal, int p_max, Vector3 *
 	r_supports[0] = point;
 }
 
-bool GodotBoxShape3D::intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal) const {
+bool GodotBoxShape3D::intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal, bool p_hit_back_faces) const {
 	AABB aabb(-half_extents, half_extents * 2.0);
 
 	return aabb.intersects_segment(p_begin, p_end, &r_result, &r_normal);
@@ -546,7 +546,7 @@ void GodotCapsuleShape3D::get_supports(const Vector3 &p_normal, int p_max, Vecto
 	}
 }
 
-bool GodotCapsuleShape3D::intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal) const {
+bool GodotCapsuleShape3D::intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal, bool p_hit_back_faces) const {
 	Vector3 norm = (p_end - p_begin).normalized();
 	real_t min_d = 1e20;
 
@@ -761,7 +761,7 @@ void GodotCylinderShape3D::get_supports(const Vector3 &p_normal, int p_max, Vect
 	}
 }
 
-bool GodotCylinderShape3D::intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal) const {
+bool GodotCylinderShape3D::intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal, bool p_hit_back_faces) const {
 	return Geometry3D::segment_intersects_cylinder(p_begin, p_end, height, radius, &r_result, &r_normal, 1);
 }
 
@@ -954,7 +954,7 @@ void GodotConvexPolygonShape3D::get_supports(const Vector3 &p_normal, int p_max,
 	r_type = FEATURE_POINT;
 }
 
-bool GodotConvexPolygonShape3D::intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal) const {
+bool GodotConvexPolygonShape3D::intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal, bool p_hit_back_faces) const {
 	const Geometry3D::MeshData::Face *faces = mesh.faces.ptr();
 	int fc = mesh.faces.size();
 
@@ -1188,12 +1188,12 @@ void GodotFaceShape3D::get_supports(const Vector3 &p_normal, int p_max, Vector3
 	r_supports[0] = vertex[vert_support_idx];
 }
 
-bool GodotFaceShape3D::intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal) const {
+bool GodotFaceShape3D::intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal, bool p_hit_back_faces) const {
 	bool c = Geometry3D::segment_intersects_triangle(p_begin, p_end, vertex[0], vertex[1], vertex[2], &r_result);
 	if (c) {
 		r_normal = Plane(vertex[0], vertex[1], vertex[2]).normal;
 		if (r_normal.dot(p_end - p_begin) > 0) {
-			if (backface_collision) {
+			if (backface_collision && p_hit_back_faces) {
 				r_normal = -r_normal;
 			} else {
 				c = false;
@@ -1304,7 +1304,7 @@ void GodotConcavePolygonShape3D::_cull_segment(int p_idx, _SegmentCullParams *p_
 
 		Vector3 res;
 		Vector3 normal;
-		if (face->intersect_segment(p_params->from, p_params->to, res, normal)) {
+		if (face->intersect_segment(p_params->from, p_params->to, res, normal, true)) {
 			real_t d = p_params->dir.dot(res) - p_params->dir.dot(p_params->from);
 			if ((d > 0) && (d < p_params->min_d)) {
 				p_params->min_d = d;
@@ -1323,7 +1323,7 @@ void GodotConcavePolygonShape3D::_cull_segment(int p_idx, _SegmentCullParams *p_
 	}
 }
 
-bool GodotConcavePolygonShape3D::intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal) const {
+bool GodotConcavePolygonShape3D::intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal, bool p_hit_back_faces) const {
 	if (faces.size() == 0) {
 		return false;
 	}
@@ -1334,7 +1334,7 @@ bool GodotConcavePolygonShape3D::intersect_segment(const Vector3 &p_begin, const
 	const BVH *br = bvh.ptr();
 
 	GodotFaceShape3D face;
-	face.backface_collision = backface_collision;
+	face.backface_collision = backface_collision && p_hit_back_faces;
 
 	_SegmentCullParams params;
 	params.from = p_begin;
@@ -1675,7 +1675,7 @@ struct _HeightmapGridCullState {
 _FORCE_INLINE_ bool _heightmap_face_cull_segment(_HeightmapSegmentCullParams &p_params) {
 	Vector3 res;
 	Vector3 normal;
-	if (p_params.face->intersect_segment(p_params.from, p_params.to, res, normal)) {
+	if (p_params.face->intersect_segment(p_params.from, p_params.to, res, normal, true)) {
 		p_params.result = res;
 		p_params.normal = normal;
 		return true;
@@ -1881,7 +1881,7 @@ bool GodotHeightMapShape3D::_intersect_grid_segment(ProcessFunction &p_process,
 	return false;
 }
 
-bool GodotHeightMapShape3D::intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_point, Vector3 &r_normal) const {
+bool GodotHeightMapShape3D::intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_point, Vector3 &r_normal, bool p_hit_back_faces) const {
 	if (heights.is_empty()) {
 		return false;
 	}
@@ -1899,7 +1899,7 @@ bool GodotHeightMapShape3D::intersect_segment(const Vector3 &p_begin, const Vect
 		// Simple case for rays that don't traverse the grid horizontally.
 		// Just perform a test on the given cell.
 		GodotFaceShape3D face;
-		face.backface_collision = false;
+		face.backface_collision = p_hit_back_faces;
 
 		_HeightmapSegmentCullParams params;
 		params.from = p_begin;
diff --git a/servers/physics_3d/godot_shape_3d.h b/servers/physics_3d/godot_shape_3d.h
index 1bbcd903f7..7a32b69166 100644
--- a/servers/physics_3d/godot_shape_3d.h
+++ b/servers/physics_3d/godot_shape_3d.h
@@ -80,7 +80,7 @@ public:
 	virtual Vector3 get_support(const Vector3 &p_normal) const;
 	virtual void get_supports(const Vector3 &p_normal, int p_max, Vector3 *r_supports, int &r_amount, FeatureType &r_type) const = 0;
 	virtual Vector3 get_closest_point_to(const Vector3 &p_point) const = 0;
-	virtual bool intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_point, Vector3 &r_normal) const = 0;
+	virtual bool intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_point, Vector3 &r_normal, bool p_hit_back_faces) const = 0;
 	virtual bool intersect_point(const Vector3 &p_point) const = 0;
 	virtual Vector3 get_moment_of_inertia(real_t p_mass) const = 0;
 
@@ -126,7 +126,7 @@ public:
 	virtual Vector3 get_support(const Vector3 &p_normal) const override;
 	virtual void get_supports(const Vector3 &p_normal, int p_max, Vector3 *r_supports, int &r_amount, FeatureType &r_type) const override { r_amount = 0; }
 
-	virtual bool intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal) const override;
+	virtual bool intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal, bool p_hit_back_faces) const override;
 	virtual bool intersect_point(const Vector3 &p_point) const override;
 	virtual Vector3 get_closest_point_to(const Vector3 &p_point) const override;
 	virtual Vector3 get_moment_of_inertia(real_t p_mass) const override;
@@ -153,7 +153,7 @@ public:
 	virtual Vector3 get_support(const Vector3 &p_normal) const override;
 	virtual void get_supports(const Vector3 &p_normal, int p_max, Vector3 *r_supports, int &r_amount, FeatureType &r_type) const override;
 
-	virtual bool intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal) const override;
+	virtual bool intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal, bool p_hit_back_faces) const override;
 	virtual bool intersect_point(const Vector3 &p_point) const override;
 	virtual Vector3 get_closest_point_to(const Vector3 &p_point) const override;
 
@@ -180,7 +180,7 @@ public:
 	virtual void project_range(const Vector3 &p_normal, const Transform3D &p_transform, real_t &r_min, real_t &r_max) const override;
 	virtual Vector3 get_support(const Vector3 &p_normal) const override;
 	virtual void get_supports(const Vector3 &p_normal, int p_max, Vector3 *r_supports, int &r_amount, FeatureType &r_type) const override;
-	virtual bool intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal) const override;
+	virtual bool intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal, bool p_hit_back_faces) const override;
 	virtual bool intersect_point(const Vector3 &p_point) const override;
 	virtual Vector3 get_closest_point_to(const Vector3 &p_point) const override;
 
@@ -205,7 +205,7 @@ public:
 	virtual void project_range(const Vector3 &p_normal, const Transform3D &p_transform, real_t &r_min, real_t &r_max) const override;
 	virtual Vector3 get_support(const Vector3 &p_normal) const override;
 	virtual void get_supports(const Vector3 &p_normal, int p_max, Vector3 *r_supports, int &r_amount, FeatureType &r_type) const override;
-	virtual bool intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal) const override;
+	virtual bool intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal, bool p_hit_back_faces) const override;
 	virtual bool intersect_point(const Vector3 &p_point) const override;
 	virtual Vector3 get_closest_point_to(const Vector3 &p_point) const override;
 
@@ -234,7 +234,7 @@ public:
 	virtual void project_range(const Vector3 &p_normal, const Transform3D &p_transform, real_t &r_min, real_t &r_max) const override;
 	virtual Vector3 get_support(const Vector3 &p_normal) const override;
 	virtual void get_supports(const Vector3 &p_normal, int p_max, Vector3 *r_supports, int &r_amount, FeatureType &r_type) const override;
-	virtual bool intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal) const override;
+	virtual bool intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal, bool p_hit_back_faces) const override;
 	virtual bool intersect_point(const Vector3 &p_point) const override;
 	virtual Vector3 get_closest_point_to(const Vector3 &p_point) const override;
 
@@ -263,7 +263,7 @@ public:
 	virtual void project_range(const Vector3 &p_normal, const Transform3D &p_transform, real_t &r_min, real_t &r_max) const override;
 	virtual Vector3 get_support(const Vector3 &p_normal) const override;
 	virtual void get_supports(const Vector3 &p_normal, int p_max, Vector3 *r_supports, int &r_amount, FeatureType &r_type) const override;
-	virtual bool intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal) const override;
+	virtual bool intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal, bool p_hit_back_faces) const override;
 	virtual bool intersect_point(const Vector3 &p_point) const override;
 	virtual Vector3 get_closest_point_to(const Vector3 &p_point) const override;
 
@@ -288,7 +288,7 @@ public:
 	virtual void project_range(const Vector3 &p_normal, const Transform3D &p_transform, real_t &r_min, real_t &r_max) const override;
 	virtual Vector3 get_support(const Vector3 &p_normal) const override;
 	virtual void get_supports(const Vector3 &p_normal, int p_max, Vector3 *r_supports, int &r_amount, FeatureType &r_type) const override;
-	virtual bool intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal) const override;
+	virtual bool intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal, bool p_hit_back_faces) const override;
 	virtual bool intersect_point(const Vector3 &p_point) const override;
 	virtual Vector3 get_closest_point_to(const Vector3 &p_point) const override;
 
@@ -366,7 +366,7 @@ public:
 	virtual void project_range(const Vector3 &p_normal, const Transform3D &p_transform, real_t &r_min, real_t &r_max) const override;
 	virtual Vector3 get_support(const Vector3 &p_normal) const override;
 
-	virtual bool intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal) const override;
+	virtual bool intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal, bool p_hit_back_faces) const override;
 	virtual bool intersect_point(const Vector3 &p_point) const override;
 	virtual Vector3 get_closest_point_to(const Vector3 &p_point) const override;
 
@@ -429,7 +429,7 @@ public:
 
 	virtual void project_range(const Vector3 &p_normal, const Transform3D &p_transform, real_t &r_min, real_t &r_max) const override;
 	virtual Vector3 get_support(const Vector3 &p_normal) const override;
-	virtual bool intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_point, Vector3 &r_normal) const override;
+	virtual bool intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_point, Vector3 &r_normal, bool p_hit_back_faces) const override;
 	virtual bool intersect_point(const Vector3 &p_point) const override;
 
 	virtual Vector3 get_closest_point_to(const Vector3 &p_point) const override;
@@ -456,7 +456,7 @@ struct GodotFaceShape3D : public GodotShape3D {
 	virtual void project_range(const Vector3 &p_normal, const Transform3D &p_transform, real_t &r_min, real_t &r_max) const override;
 	virtual Vector3 get_support(const Vector3 &p_normal) const override;
 	virtual void get_supports(const Vector3 &p_normal, int p_max, Vector3 *r_supports, int &r_amount, FeatureType &r_type) const override;
-	virtual bool intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal) const override;
+	virtual bool intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal, bool p_hit_back_faces) const override;
 	virtual bool intersect_point(const Vector3 &p_point) const override;
 	virtual Vector3 get_closest_point_to(const Vector3 &p_point) const override;
 
@@ -495,7 +495,7 @@ struct GodotMotionShape3D : public GodotShape3D {
 	}
 
 	virtual void get_supports(const Vector3 &p_normal, int p_max, Vector3 *r_supports, int &r_amount, FeatureType &r_type) const override { r_amount = 0; }
-	virtual bool intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal) const override { return false; }
+	virtual bool intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal, bool p_hit_back_faces) const override { return false; }
 	virtual bool intersect_point(const Vector3 &p_point) const override { return false; }
 	virtual Vector3 get_closest_point_to(const Vector3 &p_point) const override { return p_point; }
 
diff --git a/servers/physics_3d/godot_soft_body_3d.cpp b/servers/physics_3d/godot_soft_body_3d.cpp
index 4b3e8cc0d9..3a55870f06 100644
--- a/servers/physics_3d/godot_soft_body_3d.cpp
+++ b/servers/physics_3d/godot_soft_body_3d.cpp
@@ -1300,7 +1300,7 @@ struct _SoftBodyIntersectSegmentInfo {
 	}
 };
 
-bool GodotSoftBodyShape3D::intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal) const {
+bool GodotSoftBodyShape3D::intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal, bool p_hit_back_faces) const {
 	_SoftBodyIntersectSegmentInfo query_info;
 	query_info.soft_body = soft_body;
 	query_info.from = p_begin;
diff --git a/servers/physics_3d/godot_soft_body_3d.h b/servers/physics_3d/godot_soft_body_3d.h
index 008d5dddb8..b42fefee62 100644
--- a/servers/physics_3d/godot_soft_body_3d.h
+++ b/servers/physics_3d/godot_soft_body_3d.h
@@ -257,18 +257,18 @@ class GodotSoftBodyShape3D : public GodotShape3D {
 public:
 	GodotSoftBody3D *get_soft_body() const { return soft_body; }
 
-	virtual PhysicsServer3D::ShapeType get_type() const { return PhysicsServer3D::SHAPE_SOFT_BODY; }
-	virtual void project_range(const Vector3 &p_normal, const Transform3D &p_transform, real_t &r_min, real_t &r_max) const { r_min = r_max = 0.0; }
-	virtual Vector3 get_support(const Vector3 &p_normal) const { return Vector3(); }
-	virtual void get_supports(const Vector3 &p_normal, int p_max, Vector3 *r_supports, int &r_amount, FeatureType &r_type) const { r_amount = 0; }
-
-	virtual bool intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal) const;
-	virtual bool intersect_point(const Vector3 &p_point) const;
-	virtual Vector3 get_closest_point_to(const Vector3 &p_point) const;
-	virtual Vector3 get_moment_of_inertia(real_t p_mass) const { return Vector3(); }
-
-	virtual void set_data(const Variant &p_data) {}
-	virtual Variant get_data() const { return Variant(); }
+	virtual PhysicsServer3D::ShapeType get_type() const override { return PhysicsServer3D::SHAPE_SOFT_BODY; }
+	virtual void project_range(const Vector3 &p_normal, const Transform3D &p_transform, real_t &r_min, real_t &r_max) const override { r_min = r_max = 0.0; }
+	virtual Vector3 get_support(const Vector3 &p_normal) const override { return Vector3(); }
+	virtual void get_supports(const Vector3 &p_normal, int p_max, Vector3 *r_supports, int &r_amount, FeatureType &r_type) const override { r_amount = 0; }
+
+	virtual bool intersect_segment(const Vector3 &p_begin, const Vector3 &p_end, Vector3 &r_result, Vector3 &r_normal, bool p_hit_back_faces) const override;
+	virtual bool intersect_point(const Vector3 &p_point) const override;
+	virtual Vector3 get_closest_point_to(const Vector3 &p_point) const override;
+	virtual Vector3 get_moment_of_inertia(real_t p_mass) const override { return Vector3(); }
+
+	virtual void set_data(const Variant &p_data) override {}
+	virtual Variant get_data() const override { return Variant(); }
 
 	void update_bounds();
 
diff --git a/servers/physics_3d/godot_space_3d.cpp b/servers/physics_3d/godot_space_3d.cpp
index 77b37a2353..e2f90b90ad 100644
--- a/servers/physics_3d/godot_space_3d.cpp
+++ b/servers/physics_3d/godot_space_3d.cpp
@@ -148,7 +148,23 @@ bool GodotPhysicsDirectSpaceState3D::intersect_ray(const RayParameters &p_parame
 
 		Vector3 shape_point, shape_normal;
 
-		if (shape->intersect_segment(local_from, local_to, shape_point, shape_normal)) {
+		if (shape->intersect_point(local_from)) {
+			if (p_parameters.hit_from_inside) {
+				// Hit shape at starting point.
+				min_d = 0;
+				res_point = local_from;
+				res_normal = Vector3();
+				res_shape = shape_idx;
+				res_obj = col_obj;
+				collided = true;
+				break;
+			} else {
+				// Ignore shape when starting inside.
+				continue;
+			}
+		}
+
+		if (shape->intersect_segment(local_from, local_to, shape_point, shape_normal, p_parameters.hit_back_faces)) {
 			Transform3D xform = col_obj->get_transform() * col_obj->get_shape_transform(shape_idx);
 			shape_point = xform.xform(shape_point);