Improved readability for failing error conditions

modules/navigation/navigation_mesh_generator.cpp

@@ -489,7 +489,7 @@ NavigationMeshGenerator::~NavigationMeshGenerator() {
 }
 
 void NavigationMeshGenerator::bake(Ref<NavigationMesh> p_nav_mesh, Node *p_node) {
-	ERR_FAIL_COND(!p_nav_mesh.is_valid());
+	ERR_FAIL_COND_MSG(!p_nav_mesh.is_valid(), "Invalid navigation mesh.");
 
 #ifdef TOOLS_ENABLED
 	EditorProgress *ep(nullptr);

scene/2d/navigation_agent_2d.cpp

@@ -184,7 +184,7 @@ Vector2 NavigationAgent2D::get_target_location() const {
 Vector2 NavigationAgent2D::get_next_location() {
 	update_navigation();
 	if (navigation_path.size() == 0) {
-		ERR_FAIL_COND_V(agent_parent == nullptr, Vector2());
+		ERR_FAIL_COND_V_MSG(agent_parent == nullptr, Vector2(), "The agent has no parent.");
 		return agent_parent->get_global_position();
 	} else {
 		return navigation_path[nav_path_index];
@@ -192,7 +192,7 @@ Vector2 NavigationAgent2D::get_next_location() {
 }
 
 real_t NavigationAgent2D::distance_to_target() const {
-	ERR_FAIL_COND_V(agent_parent == nullptr, 0.0);
+	ERR_FAIL_COND_V_MSG(agent_parent == nullptr, 0.0, "The agent has no parent.");
 	return agent_parent->get_global_position().distance_to(target_location);
 }
 

scene/3d/navigation_agent_3d.cpp

@@ -192,7 +192,7 @@ Vector3 NavigationAgent3D::get_target_location() const {
 Vector3 NavigationAgent3D::get_next_location() {
 	update_navigation();
 	if (navigation_path.size() == 0) {
-		ERR_FAIL_COND_V(agent_parent == nullptr, Vector3());
+		ERR_FAIL_COND_V_MSG(agent_parent == nullptr, Vector3(), "The agent has no parent.");
 		return agent_parent->get_global_transform().origin;
 	} else {
 		return navigation_path[nav_path_index] - Vector3(0, navigation_height_offset, 0);
@@ -200,7 +200,7 @@ Vector3 NavigationAgent3D::get_next_location() {
 }
 
 real_t NavigationAgent3D::distance_to_target() const {
-	ERR_FAIL_COND_V(agent_parent == nullptr, 0.0);
+	ERR_FAIL_COND_V_MSG(agent_parent == nullptr, 0.0, "The agent has no parent.");
 	return agent_parent->get_global_transform().origin.distance_to(target_location);
 }
 

scene/3d/navigation_region_3d.cpp

@@ -162,7 +162,7 @@ void _bake_navigation_mesh(void *p_user_data) {
 }
 
 void NavigationRegion3D::bake_navigation_mesh() {
-	ERR_FAIL_COND(bake_thread.is_started());
+	ERR_FAIL_COND_MSG(bake_thread.is_started(), "Unable to start another bake request. The navigation mesh bake thread is already baking a navigation mesh.");
 
 	BakeThreadsArgs *args = memnew(BakeThreadsArgs);
 	args->nav_region = this;