O3A Directional Mask

O3A Directional Mask

Host Support

Host TypeSupport





This plugin modifies levels in a 3D O3A mix to emphasise or de-emphasise sound in a particular direction. It is similar to the O3A Directional Emphasis plugin.

The emphasis (or de-emphasis) direction can be set using the azimuth and elevation controls, or the control surface, where the direction is indicated by the crosshairs.

The algorithm used is a "passive" one and should not colour the frequency content of the sound significantly.

This plugin takes a fairly simple approach, providing control in one direction and just one further control parameter. For more sophisticated manipulations you may want to use the O3A Spatial Mask plugin.

The plugin is available in the O3A Manipulators plugin library.

View Support

When used with O3A View Sync from the O3A View library, this plugin can be connected to the separate View or ViewVR applications.

When this option is available, a 'View' button appears at the top right of the plugin's user interface.

View button

When this is pressed, the plugin is connected to the View or ViewVR application and is displayed there.

View SupportViewVR Support

The current direction is shown using a cross.

Hold the left mouse button to set the azimuth and elevation.

The current direction is shown using a beam and cross.

Hold a VR controller trigger to set the azimuth and elevation.


Controls: Azimuth and Elevation

Azimuth and Elevation control the direction to modified.

Azimuth is the horizontal angle, between -180 to +180 degrees, measured anticlockwise (left) from the front. Elevation is a vertical angle between -90 and +90 degrees, measured with positive upwards and 0 on the horizontal.

For instance, the direction for azimuth +90 and elevation +45 can be found by turning 90 degrees to the left and then looking up by 45 degrees.

Control: Sharpness

This controls the sharpness and strength of the emphasis or de-emphasis.

A value of zero means that no modification is made to the stream.

Positive values leave sound in the chosen direction as it is but reduce sound elsewhere, so that the direction is emphasised. Values near +1 provide the sharpest emphasis.

Negative values reduce the sound in the chosen direction, so it is de-emphasised.