Optical Flow

Analyses an image and visualise the movement of objects in the scene.

Method #

This node attempts to analyse an image and visualise the movement of objects in the scene, using different techniques depending on the mode selected.

Attributes

These properties control the core behaviours of the node.

Parameter	Details
Preview In Viewport	Preview the effect blended with alpha in the viewport.
Preview RGB In Viewport	Preview the colour values in the viewport.
Preview Alpha In Viewport	Preview the alpha values in the viewport.
Previous Frame Blend	How much of the previous frames blend with the current frame.
Previous Frame Directional Dependence	How much the directional movement of the previous frame affects the current frame.
Num Levels	How many levels of motion can be tracked.
Optical Flow Mode	Change the way the optical flow motion is calculated. High Quality : Uses a block matching algorithm for reasonably accurate tracking. Motion Vector Estimate : Generates smoother motion vectors but far less accurate. High Speed : A simple technique using gradients and frame differences. less accurate than high quality, but much faster. \|
Output Velocity Magnitudes	Forces the output to only show the magnitude. this only affects the output image, and not the internal motion vectors.
Output Velocity Angle And Magnitude	Outputs both the velocity angle and magnitudes. this only affects the output image, and not the internal motion vectors.
Optical Flow Scale	Scale the movement that is output.
Num Dilate Passes	How many times the dilate pass is run.

Name	Description	Typical Input
Effect Mask	Mask out areas that Post-FX applied to this node won’t be applied.	Video Loader
Alpha Image	Use a seperate video nodes luminance values to overwrite the alpha channel of the image.	Video Loader