by Melissa Raissa

Created on: November 16, 2010

Rolling object animations, such as wheels or balls, can be a fun practice in learning frame-by-frame animation. This will also compel you to study the physics behind rolling objects - how the lights, shadows or reflections change as well as the direction, speed and other important factors.  

In concept, rolling objects are basically achieved by rotating a round or circular image then aligning them incrementally to depict the movement of rolling. But if you try that approach with a solid-colored circle, you’ll find that all you’ve achieved is a colored dot sliding, and not rolling, towards its destination.

Lighting is a very subtle yet important factor in animation. If there are no changes in the light-and-shadow aspect of your animation, the viewers will be able to tell based on their real-life comparison to actual moving objects. The human eye is trained in detecting these kind of subtle changes.

The addition of details such as lines, textures or illustrations can also help in depicting a certain movement. By rotating some distinct details, like a billiard ball’s number or a basketball’s lines and texture, you can already imply movement without have to worry about lighting effects.

First, you’ll need to create a sphere image then think of the approach you want in order to achieve the rolling ball animation. If you plan on using the details approach, like a billiard ball for example, you simply add a new layer for the ball number then rotate it accordingly for your GIF animation frames.

However, this effect will only work if the details are right at the center of your sphere. A non-centered detail will take a lot more effort to achieve, since the rolling effect would need the said detail to be placed in different areas and calculated angles, but it will look more sophisticated than the centered one.

As for the lighting approach, it would help to add a new layer on top of your sphere image to depict another light source such as a ceiling light reflection. When the sphere is stationary, the top light layer is clear and steady. When the sphere rolls forward, the light is blurred and turns a few angles backwards, opposite the direction of the rolling ball.

Another way to depict a rolling ball effect is through mirrored reflections of the surroundings. Of course, there are other programs that are more appropriate for these kinds of animation but it also helps to know what goes on behind the movement especially if you‘re the one who has to provide every effect.

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