PowerPoint Animation – Tracked Vehicles 1

In the previous post, I showed you how to adapt a “rolling wheel” effect to construct conveyor belts that could be used to create lively animations that demonstrate concepts and processes.

This post is about tracked vehicles using the rolling wheel effect; here are the basics:

The wheels have a 1.0 in diameter so they will “roll” without appearing to slip if the wheel moves 3.14 in horizontally to the right while the wheels rotate 360º clockwise. The track (green outline) simply moves without additional effects. All the motions have the same duration (2 sec).  Other dimensions will work as long as the path length is 3.14 times the wheel diameter.

Here’s the animation pane:

The default Line animation Smooth Start/Stop values are set to zero in this example for simplicity.

Here’s a vehicle (bulldozer/earth mover) that I adapted from an illustration on the web:

I “traced” over the various parts of the original illustration using Freeforms and standard Shapes:

Some notes:

• The wheels use three concentric circles and a Star:10 points. The wheels must have some detail; otherwise you can’t see the rotations.
• If you are uncomfortable drawing FreeForms, you can combine standard shapes (Rectangles, Triangles, etc.) to form the component shapes (as I have done in previous posts.)
• Don’t overdo it. Exact dimensions and tiny detail are not important. You want a flat “icon style” image and enough detail to avoid a cartoon look.
• I used the Fill/Eyedropper to steal colors from the original image. Or, you can use your color scheme.

Here’s the animation:

The wheel dimensions and travel distance are the same as the previous example. The blade assembly (a Group) is animated (motion path) separately since it is in front of the track assembly which is in front of the vehicle body.

I used the Animation Painter to make the animation a little easier; here are the steps:

• First, I applied the Right motion path to the blade assembly. For this example it moves 3.14 in as in the example above.

• Next, using the Animation Painter, I copied this motion path to other parts of the machine (the body and belt assembly); the paths are identical so that the parts maintain their relationships:

• Next, I copied the motion path to the first wheel and  added the Spin animation:

• I completed the animation by copying the animations for the first wheel (Spin and motion path) to the other wheels.

Unfortunately, The Animation Painter copies all the animations of an object to a second object, replacing all of the animations of the second object. That’s why I did things in this order.

Motion paths have options called Smooth start and Smooth end. These apply an interval of acceleration and deceleration to the motion path; that is, the object starts and ends slowly.

I usually discard these options since they make it difficult to coordinate motion paths with other animations. However, in this case, the Spin animation also has this option so I can apply “smooth” motion to both the Spin and the motion path for realistic motion:

The animations have a duration of 3 seconds; the interval for the Smooth start and end is 1 sec.

Here’s an application of the bulldozer; the folks over at Acme want to eliminate your legacy technology:

Here’s the layout for this animation:

The red outlines at the right show where the blade assembly and the block will end up. For convenience, I have set the distance at 5 revolutions of the 1 in wheel (3.14).

The trick to this animation is determining when to start the motion of the stone block. You can do this by trial and error or by doing a little arithmetic. Here’s the arithmetic approach:

• The blade moves a distance of 5 times the wheel circumference (3.14 in) in 5 seconds; its speed is 3.14 in/sec.
• I added an outline of the position of the blade when it contacts the block:

• I drew an object to measure the distance the blade travels to reach this position; the distance is 6.3 in.
• The time for the blade to travel this distance is the distance divided by the speed: 6.3/3.14= 2.00 sec (I didn’t plan this convenient number). So, I began the motion of the block at 2 sec; it ends at 5 sec like the other motions.

If you work this out by trial and error, use the tools in the animation pane to adjust the start time.

Here’s an exercise for the reader: make an animation like this where the stone block breaks and piles up in front of the advancing blade.

Another familiar tracked vehicle is the military tank. Here’s one I copied from a web illustration as before:

This time, the tank is made from standard shapes. The turret uses a couple of Chord shapes to supply the curves. The track is a Union of two Rounded Rectangles and two Right Triangles. The tank track slopes upwards at both ends (to assist in climbing obstacles, I guess).

Here’s an animation:

The larger wheels are 0.8 in diameter; the distance traveled for one revolution is 2.51 in. I chose to have the tank travel three times this distance in 4 seconds so the larger wheels will rotate 3 times. The smaller wheels are half the diameter so they rotate 6 times. I used the Animation Painter as before.

Here’s the Animation Pane:

Tanks sometimes travel over rough ground – here’s a simulation of that action:

I replaced the Line motion paths for the wheels, track and track background with Zig-zag paths. However, a single Zig-zag path does not provide enough oscillations for the effect I wanted so  I used two Zig-zags back-to-back. Here’s the process:

Notes:

• I started with the “track.” After determining the length of the zig zag path, I added the motion path and extended the path to the right to the appropriate length.
• Using the handles, I re-sized/compressed the path vertically to get a smaller “bounce.”
• Since a motion path can’t be copied and pasted (!!), I added another identical path from scratch and attached it to the first half.
• Using the Animation Painter as before, a copied the path to other elements and added rotations where needed.

NOTE: You can move, re-size and rotate motion paths as if they were objects; this is sometimes simpler than editing the points of a motion path.

Another challenge for you is to represent the motion by moving the background. Here’s inspiration from an earlier post:

The “track” in these examples doesn’t move around the wheels; this is a challenge I will address in the next post. In the meantime, see the previous post for a “flicker” effect that provides an illusion of movement.

If you want to see more details, use the link below and click on the PowerPoint icon to download a free “source” PowerPoint file containing these projects:

powerpointyblog tracked vehicles 1

See this page for more on downloading files.

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