Tutorial Home / Assemble Scene / Naming and Grouping

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Overview

It is important to group together associated objects and also name those groups and objects that you later intend to animate. As your scene becomes increasingly complex, named groups of objects enable you to order your scene in a logical hierarchy. This hierarchy is also called the scene tree or scene graph.

In Cosmo Worlds the scene tree is viewed in the Outline Editor. The Outline Editor is usually visible by default but if not you can reactivate it with the icon

The Outline Editor displays each node and its Transform grouping. You can "drill-down" into the properties and sub-nodes by expanding each node.

Scene Tree Terminology: the Root Node is the grouping node at the top level of the hierarchy and may contain one or more Children. A Parent group may contain any number of Children and each Child can also be referred to as a Sibling of each other.

Example Scene Tree:

given this scene tree ... we can state the following ...
  • myHouse
    • roof
    • patio
    • kitchen
      • fridge
      • bench
      • sink
    • bedroom
      • bed
      • wardrobe
      • dresser
    • loungeRoom
      • sofa
      • coffeeTable     
      • tv
      • video

myHouse is the Root Node

kitchen is a Child of myHouse

kitchen is a Sibling of bedroom

both roof and patio have no Children

sofa and video are both Children of loungeRoom

bedroom is the Parent of bed, wardrobe and dresser

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Required Files

Download and unzip the following file (using WinZip) into the relevant folder of your working directory.

models_imported..zip (48.9Kb)

This file contains:

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Tutorial

Launch Cosmo Worlds and Open the file camera_imported.wrl

In this tutorial we're going to work from the outside-in, grouping and naming each object then hiding it so we can access underlying objects.

Conventions: the naming convention in VRML is to capitalise the second and subsequent words of a name. You cannot use spaces in a name but you may use underscore _ or hyphen - instead.

Example: Mode Dial would become modeDial.

 

Select the memory stick cover and in the Property Inspector type the name memoryStick_cover.

Hide the object.

Select the memory stick and name it memoryStick.

Hide the object.

Repeat the preceding steps to name both the battery and its cover.

Select the 3 logos on the front of the camera, Group them and name the group logos.

Hide the selected group.

Select the 2 pieces of the mode dial on the left of the camera, Group them and name the group modeDial.

Hide the selected group.

Select the 8 pieces that comprise the lens, Group and name them lens.

Important: Make sure you get all the small pieces otherwise when we set up the lens rotation later they won't rotate with the rest of the group. You'll find it easier if you select the smaller pieces first.

Hide the selected group.

Select the LED on the power button and name it powerLED. Select the button and name it powerButton.

Select both the LED and the button, Group and name them powerButtonGroup.

Hide the selected group.

Select the flash LED on the back, upper-left of the camera and name it flashLED.

Note: the LED's default state is unlit so it's a little hard to see. Refer to the illustration for its approximate location.
Select the button directly below the LED and name it flashButton.

Show All objects, Select Menu > Select All, Group and name the group camera.

Note: This step groups together all the small objects that comprise the camera, allowing us to manipulate the camera as a whole.
You can go through and name some of the remaining sub-objects of the camera but it is really only necessary to identify those objects that we are going to animate or interact with.  


Now that you have grouped everything, experiment with the other icons on the Selection Toolbar to navigate around the scene tree.

Selection Priority Highest (select groups)

Selection Priority Lowest (select objects within groups)

Select Parent Group

Select Child Object

Select Previous Sibling in Group

Select Next Sibling in Group

 
Save your work.  
Preview in Cosmo Player.  

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