Using the Scene Hierarchy

A 3D Canvas scene is made up of a hierarchy of objects much like the hierarchy of folders and files on your computer. Understanding the 3D Canvas hierarchy is important to using 3D Canvas effectively.

 

Click the Hierarchy Tab Button-Construction-Hierarchy.gif (721 bytes) to show the Hierarchy Panel in its expanded state.

When a new scene is created it isn't entirely empty. There are a number of components that are created by default with a new scene including a Point Light, the Ambient Light, two Directional Lights and the Animation Camera.

 

TutorialHierarchy1.gif (1034 bytes)

 

A 3D Canvas scene is made up of a hierarchy of frames. Frames in 3D Canvas are much like folders are in Windows. Frames are used to organize a scene, as folders are used to organize the files on your computer. A frame can contain scene components and other frames just as a Windows folder can contain files and other folders.

Frames are represented in the hierarchy by icon-Folder.gif (891 bytes).

Click on the plus sign next to the Point Light frame to expand it. It contains a Point Light. Lights are represented in the hierarchy by Icon-Light.gif (844 bytes).

 

TutorialHierarchy2.gif (1151 bytes)

 

Drag and drop a cube on to your scene.

Now drag and drop a sphere on top of the cube.
TutorialHierarchy3.gif (15501 bytes)

 

When an object is dropped on to the scene a new frame is created for that object. The new frame will be created as a child of what it was dropped on.

We dropped the cube on the scene so it became a child of the scene. We dropped the sphere on the cube so it became a child of the cube.

Expand the new items added to see this parent-child hierarchy.

Objects are represented in the hierarchy by Icon-Mesh.gif (870 bytes).

 

TutorialHierarchy4.gif (1726 bytes)

 

The term "Frame" refers to "physical frame of reference". When you select and drag a scene component, you are not dragging the component, but its frame. This results in any frames or components contained within the frame being moved also. If you rotate a component, you are not rotating the object itself, but its frame. This behavior of frames is very useful since it permits the creation of complex objects made up of many parts that behave as a single object.

Click on the cube in your scene and drag it. The sphere moves also since it is a child of the cube.

 

TutorialHierarchy5.gif (15803 bytes)

 

Click on the sphere and drag it. The cube doesn't move. This allows you to set a relative position and orientation of the child object from its parent.
TutorialHierarchy6.gif (16393 bytes)

 

Drop another cube onto the scene. Place it next to the first cube.
TutorialHierarchy7.gif (16351 bytes)

 

Frames and components can be moved within the Scene Hierarchy much like you would move folders and files with Windows Explorer.

In the hierarchy drag the new cube on to the frame that contains the first cube.

These cubes are now siblings. If you move one cube in your scene you will move the other. The behave as a single object.

Note that even though they behave as a single object they are not a single object. You could still apply an operation to one cube but not the other. If you want them to be a single object you can merge them using the Button-Toolbar-Boolean-Merge.gif (924 bytes) Merge operation.

 

TutorialHierarchy8.gif (1952 bytes)

 

Drop a cylinder on to your scene.
TutorialHierarchy9.gif (17111 bytes)

 

In the hierarchy move the frame that contains the sphere to the frame that contains the cylinder.

You have re-parented the sphere. It is now a child of the cylinder. If you move the cylinder in the scene, the sphere will move.
TutorialHierarchy10.gif (2209 bytes)

 

Click Button-Wireframe.gif (151 bytes) on the Primary Toolbar to enter wireframe mode. Click on the cylinder.

Frames are not normally visible within your scene. Only when you select an object does its frame, represented as a small yellow box, become visible. In addition to the frame being displayed, an axis is also displayed. This axis shows the orientation of the frame.

If you need to adjust the position of an object relative to its frame rather than the frame itself, you can do so using the Shift tool. This tool is often used to produce objects that rotate about a point other than the object's center.

 

TutorialHierarchy11.gif (17996 bytes)

 

To rename a scene component, click on the name of the component.

 

TutorialHierarchy12.gif (2080 bytes)

 

Clicking on an Object, Light, or Camera in the scene hierarchy results in that item being selected within the scene. Conversely, clicking on an item within the scene will select that item in the Hierarchy.

 

TutorialHierarchy13.gif (17169 bytes)

 

3D Canvas' drag and drop features apply to the Scene Hierarchy as well as the Scene. If you want, you can drag and drop a primitive, light, or other object directly on to the Scene Hierarchy Panel.

 

TutorialHierarchy14.gif (8230 bytes)