8 files changed, 57 insertions, 12 deletions
diff --git a/scene/3d/arvr_nodes.cpp b/scene/3d/arvr_nodes.cpp
index 4bff26a200..2dc500f7ab 100644
--- a/scene/3d/arvr_nodes.cpp
+++ b/scene/3d/arvr_nodes.cpp
@@ -38,14 +38,14 @@
 void ARVRCamera::_notification(int p_what) {
 	switch (p_what) {
 		case NOTIFICATION_ENTER_TREE: {
-			// need to find our ARVROrigin parent and let it know we're it's camera!
+			// need to find our ARVROrigin parent and let it know we're its camera!
 			ARVROrigin *origin = Object::cast_to<ARVROrigin>(get_parent());
 			if (origin != NULL) {
 				origin->set_tracked_camera(this);
 			}
 		}; break;
 		case NOTIFICATION_EXIT_TREE: {
-			// need to find our ARVROrigin parent and let it know we're no longer it's camera!
+			// need to find our ARVROrigin parent and let it know we're no longer its camera!
 			ARVROrigin *origin = Object::cast_to<ARVROrigin>(get_parent());
 			if (origin != NULL) {
 				origin->clear_tracked_camera_if(this);
diff --git a/scene/3d/arvr_nodes.h b/scene/3d/arvr_nodes.h
index 67fb658562..d6690676cc 100644
--- a/scene/3d/arvr_nodes.h
+++ b/scene/3d/arvr_nodes.h
@@ -62,7 +62,7 @@ public:
 };
 
 /*
-	ARVRController is a helper node that automatically updates it's position based on tracker data.
+	ARVRController is a helper node that automatically updates its position based on tracker data.
 
 	It must be a child node of our ARVROrigin node
 */
@@ -102,7 +102,7 @@ public:
 };
 
 /*
-	ARVRAnchor is a helper node that automatically updates it's position based on anchor data, it represents a real world location.
+	ARVRAnchor is a helper node that automatically updates its position based on anchor data, it represents a real world location.
 	It must be a child node of our ARVROrigin node
 */
 
diff --git a/scene/3d/light.cpp b/scene/3d/light.cpp
index 7e1d60ab8e..11d61315ba 100644
--- a/scene/3d/light.cpp
+++ b/scene/3d/light.cpp
@@ -163,11 +163,6 @@ void Light::_update_visibility() {
 	if (!is_inside_tree())
 		return;
 
-	// FIXME: Since the call to VS::instance_light_set_enabled was disabled below,
-	// the whole logic became pointless so editor_ok triggers unused variable warnings.
-	// Commenting out for now but this should be fixed/reimplemented so that editor_only
-	// works as expected (GH-17989).
-	/*
 	bool editor_ok = true;
 
 #ifdef TOOLS_ENABLED
@@ -184,8 +179,8 @@ void Light::_update_visibility() {
 	}
 #endif
 
-	//VS::get_singleton()->instance_light_set_enabled(get_instance(),is_visible_in_tree() && editor_ok);
-	*/
+	VS::get_singleton()->instance_set_visible(get_instance(), is_visible_in_tree() && editor_ok);
+
 	_change_notify("geometry/visible");
 }
 
diff --git a/scene/3d/mesh_instance.cpp b/scene/3d/mesh_instance.cpp
index 4cbf6f2de3..cf0317cd58 100644
--- a/scene/3d/mesh_instance.cpp
+++ b/scene/3d/mesh_instance.cpp
@@ -253,6 +253,11 @@ void MeshInstance::_notification(int p_what) {
 	}
 }
 
+int MeshInstance::get_surface_material_count() const {
+
+	return materials.size();
+}
+
 void MeshInstance::set_surface_material(int p_surface, const Ref<Material> &p_material) {
 
 	ERR_FAIL_INDEX(p_surface, materials.size());
@@ -359,6 +364,7 @@ void MeshInstance::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("set_skeleton_path", "skeleton_path"), &MeshInstance::set_skeleton_path);
 	ClassDB::bind_method(D_METHOD("get_skeleton_path"), &MeshInstance::get_skeleton_path);
 
+	ClassDB::bind_method(D_METHOD("get_surface_material_count"), &MeshInstance::get_surface_material_count);
 	ClassDB::bind_method(D_METHOD("set_surface_material", "surface", "material"), &MeshInstance::set_surface_material);
 	ClassDB::bind_method(D_METHOD("get_surface_material", "surface"), &MeshInstance::get_surface_material);
 
diff --git a/scene/3d/mesh_instance.h b/scene/3d/mesh_instance.h
index 0dfec538f9..0b5b4b9e7b 100644
--- a/scene/3d/mesh_instance.h
+++ b/scene/3d/mesh_instance.h
@@ -76,6 +76,7 @@ public:
 	void set_skeleton_path(const NodePath &p_skeleton);
 	NodePath get_skeleton_path();
 
+	int get_surface_material_count() const;
 	void set_surface_material(int p_surface, const Ref<Material> &p_material);
 	Ref<Material> get_surface_material(int p_surface) const;
 
diff --git a/scene/3d/path.cpp b/scene/3d/path.cpp
index e37efa0e8a..339a434a6e 100644
--- a/scene/3d/path.cpp
+++ b/scene/3d/path.cpp
@@ -43,6 +43,16 @@ void Path::_curve_changed() {
 	if (is_inside_tree()) {
 		emit_signal("curve_changed");
 	}
+
+	// update the configuration warnings of all children of type OrientedPathFollows
+	if (is_inside_tree()) {
+		for (int i = 0; i < get_child_count(); i++) {
+			OrientedPathFollow *child = Object::cast_to<OrientedPathFollow>(get_child(i));
+			if (child) {
+				child->update_configuration_warning();
+			}
+		}
+	}
 }
 
 void Path::set_curve(const Ref<Curve3D> &p_curve) {
@@ -207,6 +217,18 @@ void PathFollow::_validate_property(PropertyInfo &property) const {
 	}
 }
 
+String PathFollow::get_configuration_warning() const {
+
+	if (!is_visible_in_tree() || !is_inside_tree())
+		return String();
+
+	if (!Object::cast_to<Path>(get_parent())) {
+		return TTR("PathFollow only works when set as a child of a Path node.");
+	}
+
+	return String();
+}
+
 void PathFollow::_bind_methods() {
 
 	ClassDB::bind_method(D_METHOD("set_offset", "offset"), &PathFollow::set_offset);
@@ -444,6 +466,23 @@ void OrientedPathFollow::_validate_property(PropertyInfo &property) const {
 	}
 }
 
+String OrientedPathFollow::get_configuration_warning() const {
+
+	if (!is_visible_in_tree() || !is_inside_tree())
+		return String();
+
+	if (!Object::cast_to<Path>(get_parent())) {
+		return TTR("OrientedPathFollow only works when set as a child of a Path node.");
+	} else {
+		Path *path = Object::cast_to<Path>(get_parent());
+		if (path->get_curve().is_valid() && !path->get_curve()->is_up_vector_enabled()) {
+			return TTR("OrientedPathFollow requires up vectors enabled in its parent Path.");
+		}
+	}
+
+	return String();
+}
+
 void OrientedPathFollow::_bind_methods() {
 
 	ClassDB::bind_method(D_METHOD("set_offset", "offset"), &OrientedPathFollow::set_offset);
diff --git a/scene/3d/path.h b/scene/3d/path.h
index f73bf17dfe..beb37d9714 100644
--- a/scene/3d/path.h
+++ b/scene/3d/path.h
@@ -106,6 +106,8 @@ public:
 	void set_cubic_interpolation(bool p_enable);
 	bool get_cubic_interpolation() const;
 
+	String get_configuration_warning() const;
+
 	PathFollow();
 };
 
@@ -151,6 +153,8 @@ public:
 	void set_cubic_interpolation(bool p_enable);
 	bool get_cubic_interpolation() const;
 
+	String get_configuration_warning() const;
+
 	OrientedPathFollow();
 };
 
diff --git a/scene/3d/voxel_light_baker.cpp b/scene/3d/voxel_light_baker.cpp
index 541f6047d9..0eccbbc8f9 100644
--- a/scene/3d/voxel_light_baker.cpp
+++ b/scene/3d/voxel_light_baker.cpp
@@ -261,7 +261,7 @@ static _FORCE_INLINE_ void get_uv_and_normal(const Vector3 &p_pos, const Vector3
 void VoxelLightBaker::_plot_face(int p_idx, int p_level, int p_x, int p_y, int p_z, const Vector3 *p_vtx, const Vector3 *p_normal, const Vector2 *p_uv, const MaterialCache &p_material, const AABB &p_aabb) {
 
 	if (p_level == cell_subdiv - 1) {
-		//plot the face by guessing it's albedo and emission value
+		//plot the face by guessing its albedo and emission value
 
 		//find best axis to map to, for scanning values
 		int closest_axis = 0;