Mach1 Spatial Headtracking Examples

Demos

List of already deployed demos utilizing concepts of Mach1 Spatial and facetracking

• Dual Layer Mach1Spatial (Branch: /demo-example/dual-layer)
• Mach1Spatial + Stereo Object (Branch: /demo-example/depth-object)
• Content Demos

Description

A consolidated web spatial audio player for Mach1 Spatial playback with two goals:

• Exploration of different methods of orientation sensing and best practices for headtracking UX as an ongoing R&D project for spatial and multichannel audio playback
• Simplified playback tool that in concert with Mach1Transcode API can aggregate all soundfield formats and play them back with a simple single player object

Setup

• Use ./download-audiofiles.sh (or ./download-audiofiles.bat if on WIN) to download some prepared debug playback audio

Usage

We have exposed some settings to extend usability of the facetracker mode.

• yawMultiplier - Multiplies the yaw rotation to allow experimentation with extending the limited range of motion from "facetracking", making it 1.0 is recommended for natural headtracking however raising it up to 2.0 is still believable in terms of associating the audio results with your headtracking motion; anything past 2.0 breaks immersion
• pitchMultiplier - Multiplies the pitch rotation to allow experimentation with extending the limited range of motion from "facetracking", we found it to be best to keep it as close to 1.0 as possible
• rollMultiplier - Multiplies the roll rotation to allow experimentation with extending the limited range of motion from "facetracking", we found it to be best to keep it as close to 1.0 as possible
• FOV - We clamp the yaw range from "facetracking" to lessen low confidence results from causing large rotation jumps when unable to view full face
• filterSpeed - An additional filter to smooth results applied to Mach1Decode during audio playback to stereo
• oneEuroFilterBeta - The filter beta for the 1Euro implementation

Orientation Inputs

Facetracking

After exploring several web based facetrackers we have had the most success with MediaPipe FaceMesh. Landmark tracking with FaceMesh wasn't designed for us to calculate orientation rotations to be applied to something as sensitive as spatial audio playback, so we had to apply a filter to the motion results to "smooth" out any low frequency jitters. This can be seen via the 1Euro filter implementation:

window.createOneEuroFilters = function createOneEuroFilters() {
    fYaw = OneEuroFilter(60, 1.0, window.controls.oneEuroFilterBeta, 1.0);
    fPitch = OneEuroFilter(60, 1.0, window.controls.oneEuroFilterBeta, 1.0);
    fRoll = OneEuroFilter(60, 1.0, window.controls.oneEuroFilterBeta, 1.0);
};

Mobile Device IMU

Running this demo on a mobile device will now use the device's IMU sensor with gimbal rotations to ensure holding in portrait mode will have a smooth and expected full 3DOF rotations.

Mouse UI

When utilizing Touch mode a simple mouse control bound to width of window will be used as the input orientation for the Mach1Decode object(s) and for the OSC output.

Bose AR IMU

When utilizing Bose AR mode a connection prompt and handler supplied by the BoseAR Web SDK will be utilized for the input orientation for the Mach1Decode object(s) and for the OSC output.

License

Use of the Mach1Decode API in this example falls under the license supplied in this repo and derived from the Mach1 Spatial SDK viewable here