# World Frame and Axis {% hint style="info" %} The Gazebo version is Fortress {% endhint %} We have already seen that the root node in a `sdf` file is `` and other entities are the child node of the world. The frame of this world node is the world frame. The easiest way to visualize it is to create a box entity and set the pose to (0,0,0). If we run the command `ign gazebo shapes.sdf`, it brings a default world with shapes and the box is put at the origin of the world with an offset in z-axis. To dislay the axis, we can use click the translate button and then select the red box. **The red arrow represents the x-axis, green the y-axis, and blue the z-axis.**
Strictly speaking, the axis displayed in the figure above is the axis of the local frame of the red box. It just happens that it aligns with the world frame in the shape.sdf file. To verify it's the axis of the local frame, we can rotate the box and see the effect:
Note that if we now translate the red box, it moves along the local axis. If we want to translate a rotated entity along the world frame axis, we can hold the shift key and drag the object. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://www.learnros2.com/gazebo/world-frame-and-axis.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.