Motion Blur
The streaking or smearing of an image caused by subject or camera movement during the exposure period. Appears as directional blur along the axis of motion.
Motion blur is the phenomenon where an image stretches along the direction of movement due to displacement during exposure. Longer shutter speeds and faster velocities produce greater blur. Human vision naturally perceives motion blur, making it essential for realism in rendered imagery.
Shutter angle controls blur amount in cinematography. The film standard is 180 degrees - shutter open for 50% of the frame interval, approximately 1/48 second at 24fps.
- Linear motion blur: Caused by straight-line movement. The PSF approximates a rectangular function along the motion direction, making
deconvolutionrestoration tractable - Rotational motion blur: Produced by spinning objects like propellers. The PSF follows an arc pattern requiring specialized algorithms
- CG motion blur: Renderers compute per-pixel velocity vectors and apply blur as post-process. Higher sample counts yield smoother results at increased cost
- Deblurring: Deep learning methods restore sharp images from blurred inputs, estimating both blur kernel and latent image simultaneously
Game engines implement screen-space motion blur using velocity buffers. Separating camera from per-object blur allows independent quality control and artistic decisions.