Motion Blur


Generates artificial motion blur using optical flow analysis of movement between frames.

Item

Description

Mode

Choose between using the composition's motion blur settings or your own custom settings.

Shutter Angle

A larger shutter angle will create more motion blur. The shutter angle simulates the amount of time a real camera shutter is open.

Shutter Phase

Positions the blur in relation to the movement of objects between frames. This can be used to offset the blur in front of or behind the object. For realistic motion blur this is best kept to half the value of the shutter angle.

Samples

Motion blur is constructed by sampling the position of objects over multiple frames. A higher number of samples will result in a higher quality motion blur. Fewer samples will be faster to render but may introduce visible banding in the motion blur.

Window Size

The number of pixels around the current pixel being tracked using optical flow. Used to calculate motion of each pixel. Larger window sizes may impact performance.

Sigma

Alters the algorithm used for tracking. If footage is not being tracked successfully try adjusting the sigma.

Iterations

Number of times the optical flow algorithm is performed before converging to a solution. More iterations will result in longer calculations.

Downsamples

To avoid tracking noise within the frame multiple downsamples of the frame are created and analyzed through optical flow. More downsamples provides more data.

Start Downsample

0 = the original, full resolution frame. By default this is set to 1, which means the analysis begins with the first downsampled version, avoiding errors through analysis of noise in the frame. Starting at a higher downsample results in faster calculations but less accuracy as the analyzed frames are increasingly low resolution.