Using a Camera in 3D - Flash 3D: Animation, Interactivity, and Games - page 252

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// set the viewer destination coordinates

viewer.dx = thisObj.x;

viewer.dy = thisObj.y;

viewer.dz = thisObj.z/2;

// prepare for zooming in on the flag

zoomIn = true;

// identify the flag number

mySelection = k;

// store its z-coordinate and depth

zdata[numberOfObjects] = zdata[mySelection-1]

myDepth = thisObj.getDepth();

thisObj.swapDepths(30000);

break; // break out of the loop

Step 6: Complete the script for zooming in

The onEnterFrame handler is where the actual work of zooming in takes place. There
is a fair amount of new code here, and everything between the lines

// move the viewer towards the selected flag

and

// zoom out when the background has been clicked

should be deleted and replaced with the script shown here.

We begin by moving the viewer towards the selected flag as before. We define vari-
ables diffx , diffy , and diffz , which are measures of the difference between the
destination and current positions of the viewer in the x-direction, y-direction, and
z-direction respectively (lines 144-146). A variable difft , which is a rough measure
of the total difference, is also defined (line 147). The first three variables are used to
move the viewer toward the flag and are the same as previously, just written differ-
ently (lines 149-151).

The variable difft is used to determine basically when the viewer has reached the
destination position. When this number is small enough, less than 6 in this case, and
if zoomIn has been set to true, then we will start to zoom in on the flag (line 155).

The process of zooming the flag is done in equal increments. Each time the frame is
entered, step is incremented by 1 (line 157). The z-coordinate of the flag is updated