Exercise: Try and make a list of more shapes like the cuboid and sphere that can be created using 3D software. Then go to the create primitives option in your software and see whether they are there. If you do not know how to do that, please refer to your software help.

How many of these objects were available as primitives in your software? Most likely all of them and perhaps some more.

This video will give a brief introduction to creating primitives. We have used Maya, but it will not be too different in most other software.

Video - Creating Primitives

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Let us get a bit more familiar with the actual process of object creation. Though we are talking of primitives, this is essentially the same for the geometry of all objects.

Inputs -  i.e. some method of telling the software what you want to create. In our example, to create the cuboid, we first let the software know it’s length, width and height, either interactively in the viewports or by entering values in the fields that the software provided. What the software does is create the geometry for you. This geometry is essentially made of

• Vertices in 3D space, each with its x, y, and z coordinates, which are all grouped together as your object
• Polygons which connect these vertices to create the faces of the object

Modifying the object - This collection of vertices and polygons can be then changed in various ways to get other shapes. We will look at this in more detail in the coming parts.

The body of Wow is a cuboid, which has been tapered so that it is narrower at the bottom to resemble an exclamation mark.

Placing it in the Virtual World - This geometry is a part of a virtual world and hence the software needs to know what are it’s ‘world co-ordinates’ in terms of position, orientation and scale. It will also need to know some other properties like visibility. This way, it can be placed in relation to other objects and becomes a part of the 3D environment.

You can see how this works in the title sequence of our modules, where Wow is standing on the diving board, which again is nothing but a cuboid shape!

This process of Creation of geometry, Modification and Placement in the World is essentially the same even if there are innumerable methods of going about it.

Please note: There is a difference in increasing the size of the object by scaling it as compared to changing the parameters of the primitive object even though both might look the same.
For example: Creating a cube with length, width and height of all 10 and scale values of x, y, and z all 1 as compared to length, width and height of all 5 and scale values of x, y, and z all 2.

So as you become more familiar with the techniques of 3D, it will also be important when you are creating a 3D object to first explore and figure out what is the best method of creating the object that you desire.

Practice creating various primitives and then modifying their values. Familiarize yourself with how and where the object properties are displayed in your software. This will be a great help later, a lot more than you can imagine.