Motion blur is a naturally occurring visual phenomenon when objects move through space too fast for the human eye to capture full visual fidelity. On film, motion blur occurs when an object’s position changes during the interval when a camera’s shutter is open, capturing either a single still or a frame in a sequence of video and resulting in a distinctive blurring.
CGI animation and VFX content for film, TV, and games is made up completely of still images with none of the visual properties associated with movement, even if they depict a moving object. A motion blur effect in animation applies the blur effects seen in real life to content, making it appear more realistic.
In video games, the addition of motion blur can enhance the realism of the animations. Image courtesy of Blind Visual Propaganda.
Things in nature move constantly, but every frame of animation used in films, TV, and video games is perfectly still. The projecting or playback of frames in sequence over time tricks the eye into seeing movement. Because objects in the real world sometimes move faster than the human eye (just watch as you click your fingers), the motion blur effect is a feature of human visual acuity, with the brain correcting for representation of real-world physics.
Animated VFX doesn’t capture a discrete moment in time, like the eye or the camera, so it doesn’t contain motion blur when creating a completely still scene from the ground up. As a result, it can look strangely “off” because moving objects are unnaturally sharper than in real life. To address this, animators and VFX artists use software that can create and add motion effects to create a more realistic-looking CGI environment in an animated scene.
Advanced hardware allows VFX artists to apply different amounts motion blur to different elements in a scene. Image courtesy of Leviathan.
Basic motion blur in games, animations, and videos run on older hardware was done on a global basis, most commonly by gradually reducing the opacity of the previous frames while gradually increasing the opacity of the next few frames, giving the entire scene a consistent application of motion blur.
More advanced hardware has allowed for per-pixel or per-object motion blur, where the system is aware of the differences between individual visual elements from one frame to the next and applies the appropriate motion blur to them automatically—in many cases, down to the individual pixels comprising the object.
And finally, designing and deploying different types of motion blur in games or video footage will advance greatly with the development of AI motion blur algorithms that automate the whole process.
A successful motion blur effect is something VFX designers aspire to because it emulates the way viewers see the real world, making video footage more realistic. Some benefits include:
Today, a vast amount of live-action film and TV footage is augmented using animated VFX, even if it’s just for color grading or environmental effects. Any rapidly moving elements captured by a camera will show motion blur naturally, so motion effects applied to animated elements in the frame help sell the illusion, more closely matching the way objects really move.
Because the human brain is built to synthesize and filter motion blur effects the eye transmits to it in everyday life, it expects to see it everywhere. That means hard resets of frames in video content with no motion blur to smooth the transitions between them appear jagged or jumpy, a reaction that may not be completely conscious but results in the footage feeling wrong.
Like all graphical or animated effects, motion blur is used to evoke an emotional response in the viewer or player. Using it appropriately for the scene, environment, other elements in the frame, or the kinetic “personality” of the visual story being told is a handy way to elevate the audience’s experience and their investment in it.
In film, TV, or games, it’s sometimes necessary or beneficial to direct the user’s attention to a specific area of the image to guide them through the story. Because the eye tends to focus on the sharpest part of the visual field both in life and in animation, VFX designers or directors can apply motion blur everywhere in an image except where they want the viewer to pay the most attention.
Scale your studio’s rendering and simulation capabilities, while equipping artists with powerful modeling and animation tools
STEFAN LOPUSNY
Based in the Netherlands and Greece, Fat Tony Studio specializes in visualizations for the architecture industry. Created by art director Stefan Lopusny, the short film In Circles features a series of spinning tops playfully dancing around a contemporary urban kitchen. Along with designing elements, creating and lighting the scene, and animating the movement of the virtual camera and the various spinning toys, a motion blur effect was applied to reduce flickering around the edges of moving elements.
Image courtesy of Stefan Lopusny
IMPORTANT LOOKING PIRATES
The 2012 adventure film Kon-Tiki featured an arresting shot of a Great White shark dragged aboard the titular Norwegian wooden raft. The Stockholm VFX provider Important Looking Pirates animated the shark from the ground up, using multiple textures for realistic skin, photorealistic color and shading effects, and motion blur to complete background information.
Image courtesy of Important Looking Pirates
Explore the complete guide to designing and deploying motion blur in Autodesk Arnold, Autodesk’s 3D rendering tool.
This help page on Autodesk 3ds Max explains some of the methods you can use to apply motion blur to a scene, object, or frame.
Explore the complete guide to designing and deploying motion blur in Autodesk Arnold, Autodesk’s 3D rendering tool.
From Autodesk Research, TimeTunnel is a proposed system that makes editing character motion in VR easier by combining the controls for changes in spatial and temporal data.
Motion blur emulates the naturally occurring blurring effect that occurs when objects move too quickly for the human eye to see detail, adding it to animated video content in film, TV, or games.
Motion blur in games has a long and controversial history, and many gamers disable it completely when the game software allows. But like all technologies, motion blur only has a detrimental effect when misused or not implemented correctly. Often, successful motion blur is a careful compromise between frame rate refresh, the hardware available to render it, and global- versus object-based blur control. A skilled director, production company, or studio must decide where best to concentrate the available render power.
Motion blur is related to but not directly connected to frames per second (FPS), and you can apply motion blur effects regardless of the frame rate of your footage or gameplay without necessarily increasing it. Generally, motion blur can make video with a low frame rate look a little more realistic. However, the metric isn’t constant as the FPS increases because at a far higher frame rate, motion can be completely invisible or negatively affect the visual fidelity of the image.
