Disabled depth test for line and handle materials

editor/plugins/polygon_3d_editor_plugin.cpp

@@ -560,6 +560,7 @@ Polygon3DEditor::Polygon3DEditor() {
 	line_material->set_flag(StandardMaterial3D::FLAG_ALBEDO_FROM_VERTEX_COLOR, true);
 	line_material->set_flag(StandardMaterial3D::FLAG_SRGB_VERTEX_COLOR, true);
 	line_material->set_flag(StandardMaterial3D::FLAG_DISABLE_FOG, true);
+	line_material->set_flag(StandardMaterial3D::FLAG_DISABLE_DEPTH_TEST, true);
 	line_material->set_albedo(Color(1, 1, 1));
 
 	handle_material.instantiate();
@@ -569,6 +570,7 @@ Polygon3DEditor::Polygon3DEditor() {
 	handle_material->set_flag(StandardMaterial3D::FLAG_ALBEDO_FROM_VERTEX_COLOR, true);
 	handle_material->set_flag(StandardMaterial3D::FLAG_SRGB_VERTEX_COLOR, true);
 	handle_material->set_flag(StandardMaterial3D::FLAG_DISABLE_FOG, true);
+	handle_material->set_flag(StandardMaterial3D::FLAG_DISABLE_DEPTH_TEST, true);
 	Ref<Texture2D> handle = EditorNode::get_singleton()->get_editor_theme()->get_icon(SNAME("Editor3DHandle"), EditorStringName(EditorIcons));
 	handle_material->set_point_size(handle->get_width());
 	handle_material->set_texture(StandardMaterial3D::TEXTURE_ALBEDO, handle);