The Power of Bezier Curves in Video Editing for Smoother Keyframe Interpolation

Examine the work of professional video editors carefully, and you’ll notice that their animations, zoom, and transitions are silky smooth. Step back and consider your own work – how does it compare? Are your zooms and pans abrupt and shaky? Do they look unnatural and forced? If the answer is yes, you need to understand the power of Bezier curves and how you can use them to up your video editing game, no matter what kind of project you’re working on.

What Are Bezier Curves (and Why Should I Care)?

The mathematics behind Bezier curves has been known and understood since the early 20^th century. By the mid-20^th century, they were applied to design, allowing smooth curves to be generated by the application of a few control points. These curves can be easily “scaled up,” so they’re well-suited for design applications.

In video editing and video animation, Bezier curves are an excellent way to specify the velocity of an object over time. This provides a template for objects to move smoothly or allows pans and zooms to occur in a natural, organic way. That’s a vital aid in the video editing process.

Common Bezier Curve Applications

Bezier curves are used in a variety of applications directly and indirectly related to video production and editing. Here are some of the most common ways that they’re utilized.

• Digital Graphics – Digitally created graphic elements are at the heart of many video production. Drawings and images require smooth curves that can be scaled up or down with accuracy, as well as be quickly and easily adjusted to modify the shape. Bezier curve-based drawing tools in digital graphics creation applications make these much easier to accomplish.
• Animation – When creating animation for video production and editing, smooth motion is an essential element in producing work that’s realistic. Consider your own body – if you’re performing a motion like swinging a hammer, your arm will accelerate throughout the movement. Bezier curves allow animation of this action to replicate this steady acceleration at the beginning and quick deceleration at the end.
• Video – Consider the number of effects that you may add to a video editing project. Changes in opacity, color grading, and correction, zooms, pans, transitional dissolves – all of these can benefit from the application of Bezier curves to create a smooth effect, as opposed to a constant steady-state change.

Some Common Examples of Bezier Curve Keyframe Interpolation

Let’s look at a few other real-world examples where Bezier curves play a big role in smoothing out your transitions between keyframes in the video editing process.

• Zooms and Pans – In video editing your work should be either completely obvious or so subtle that the viewer doesn’t realize you’re using an effect to influence their perception of the scene. For the first instance, consider an effect like the snap zoom. These quick zooms in and out will ratchet up the excitement of an action scene, like a chase or an aerial dogfight. An abrupt start and stop are perfectly suitable. But with more subtle zooms and pans, it’s important to vary the speed of the effect. For example, you can slowly zoom in on a character to build tension as they reveal a secret. Utilizing a Bezier curve to slowly initiate the beginning and end of the zoom creates a subtler effect.
• Text and Titling – The role of Bezier curves in smooth keyframe interpolation may not bring text and titling elements to mind, but text and titling animation can benefit from the smoother interpolation between keyframes that Bezier curves yield. Animated typography and titling sequences often employ elements of text in motion to catch the attention of viewers. The process of sliding a text block in or out of the frame of your video will look much more polished and professional if there’s a corresponding acceleration or deceleration to match the beginning and end of the movement.
• Animation Elements – Animation elements must be constructed and deployed realistically for maximum effectiveness. When the animation element is being manipulated in a 3D environment over time and distance, the smoothing motion of a Bezier curve is vital. Here’s an example: an animated vehicle approaching from a distance must accelerate in the eye of the viewer, just like you would encounter if you were watching a car approach you on a country road. A Bezier curve can provide the timing to make this process realistic.

Use Bezier Curves

You don’t need to be a mathematical genius to use Bezier curves. Most popular video editing and animation creation programs include tools that allow you to adjust your keyframe interpolation with the use of Bezier curves. As with learning any new skill set, there can be a learning curve, but once you jump in you’ll find that your progress will accelerate (like a Bezier curve) once you dig in. Search for tutorials and experiment in your work. The results will be noticeable, as your work takes on a more polished and professional look.

– Video Caddy