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# Node Structure
RealityHub visualizes Engine entities as nodes inside the Nodegraph/Actions module.
To set an example, RealityHub reads Reality Engine nodes and visualizes them inside its Nodegraph. Then, depending on the logical connections between nodes, it creates a node tree, triggers functions & sends commands to a targeted pipeline in real-time.
Node Structure
A node has various visual attributes, as shown in the image above.
### Debugging Mode
In RealityHub terminology, debugging mode refers to a **unique state** which activates several features such as visualization.
Not all nodes support debugging mode. The most common debugging uses **`Cyclorama`**, **`ProjectionCube`**, **`Camera`**, and Lights in a live production workflow.
The reason behind the Debugging Mode is to help you adjust various features of your live production scene without going back and forth to the Reality Engine.
### GamePad
This feature provides input to various nodes to control them in a three-dimensional space. This feature becomes useful when you want to change, for instance, the X, Y, Z, Roll, Yaw, and Pitch axis of a **`Camera`** inside your scene via RealityHub.
Instead of typing inputs manually, GamePad allows you to change your **`Camera`** axis into a free look (a.k.a, mouselook) like playing a first-person shooter game.
To use GamePad:
* Select a **`Camera`** node
* Click on the **`GamePad`** **Activation Button**
As soon as you click on the **`GamePad`** activation button:
1. The **GamePad Navigation Tool** inside the Nodegraph view gets activated
2. **`GamePad`** button turns to blue, as shown in the image above
* Click and hold your right mouse button on the GamePad Navigation Tool
* Using **WASDQE** keys transforms you into a 3d space
* Moving your mouse gives you the ability to freelook
### Active and Passive Attributes
As shown in the image above, active, and passive node elements differ from one another.
### Pin Coloring
RealityHub reflects the actual state inside the Reality Engine, and each node can be connected to the **associated node**(s).
You can establish a connection between **logically matching nodes**. To help you distinguish node classes, RealityHub utilizes the Pin Coloring method, as shown in the image above.