Motion blur
Motion blur is the streaky blur that follows the direction of objects in a motion relative to the camera movement. This is due to long exposure or object/camera rapid motion. Adding this simulation to the composite image also adds realism.
The Vector Blur node
The Vector Blur node in Blender provides an effective motion blur solution in compositing. This node requires vector data and depth data connected to Speed and Z, respectively.
Tip
Transform information of a specific point travelled in relation to the previous and next frames is stored as a vector pass, also called Motion Vectors.
The following is list of the Vector Blur node attributes:
Samples: This defines the quality of the blur
Blur: This specifies the amount of the blur in pixels
Min: This is the threshold for the slowest moving points of the image
Max: This is the threshold for the fastest moving points of the image
The following screenshot illustrates Motion Blur, simulated using the Vector Blur node: