Datasheet

Chapter 1: Understanding Flash3D

In Chapter 2, you ’ ll find out how to obtain the Papervision3D classes and how to drill down and

examine its code. This particular code snippet is found in the

org/papervision3d/camera folder.

if (screen.visible = ( focus + s_z > 0 ))

{

s_x = vx * m11 + vy * m12 + vz * m13 + view.n14;

s_y = vx * m21 + vy * m22 + vz * m23 + view.n24;

//perspective scaling in Papervision

persp = fz / (focus + s_z);

screen.x = s_x * persp;

screen.y = s_y * persp;

screen.z = s_z.

}

The code snippet above taken from Papervision3D ’ s Camera3D class demonstrates how Papervision3D

uses perspective scaling. You ’ ll use this idea to create a 3D Flash engine in just 19 lines of code.

Coding Animation

Okay, you should now understand enough about perspective scaling to begin coding your 3D engine. In

this example, you create your code in the Flash API, but many Papervsion3D developers use either Flex

or Eclipse for their code development work. Flex and Eclipse offer superior code debugging and code

hinting capabilities over Flash, and in many instances their use speeds your code development by a

factor of 4. It ’ s worth trying one of them out.

In this exercise, you ’ ll create a circle that oscillates in and out of the screen in the z perspective direction.

Whether using the timeline or pure ActionScript, Flash in essence is an animation machine. When using

purely scripted animation, the animation process is based upon a looping (or updating) procedure

shown in Figure 1.5.

Grab Imports

Set Initial Parameters

Create Graphical

Elements

Listener

Render

Frame

Display

Frame

Alter

Frame

Figure 1-5

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