Ambi Encoder Point

s3g Ambi Encoder Point is a variable 1-to-64-point ambisonic encoder. Each mono input lane is treated as a point source with azimuth, elevation, distance, gain, mute, and solo state. New instances start with 16 active points.

The selectable output spans first- through seventh-order ambisonics in ACN/SN3D. The plugin is for point-source placement and motion-controlled spatial scenes, not for generic channel fold-down.

Workflow

1. Set the REAPER track to 64 channels, insert s3g Ambi Encoder Point, select the ambisonic ORDER, choose POINTS from 1 to 64, and route mono source lanes to the corresponding inputs.
2. Follow it with an ambisonic decoder.
3. Place each active point with azimuth, elevation, distance, and gain.
4. Use MOTION: OFF / MANUAL for direct editing or REAPER automation, or choose a motion engine and compatible style.
5. Use the field, mixer, and physics views to refine the point relationships.

Field View

The FIELD page is the main spatial display. It draws active points, point IDs, a nearest-neighbor analysis graph, and the selected point readout.

• TOP view uses the project convention: 0 degrees at the top, 180 at the bottom, -90 right, and +90 left.
• SIDE view draws positive elevation upward.
• 3/4 view is for inspection. Drag blank space to rotate the camera.
• - / + zoom buttons change only the camera view, not AED distance values.
• Click a point to select it. Click blank space to deselect all points.

The nearest-neighbor lines are an analysis and physics readout, not fixed audio routing. In scenes that use bonds, the lines show which points are currently connected by the internal point network. When a Geist strike breaks local bonds, those lines disappear and fade back as the network heals.

Point Editing

Points can be edited directly in views where the mouse plane maps clearly to AED.

• In TOP, dragging a point edits azimuth and distance while preserving elevation.
• In SIDE, dragging a point edits elevation and the side axis while preserving the hidden depth component.
• In 3/4 or manually rotated views, clicking selects points and blank-field dragging rotates the view.

The right-side POINT panel edits the selected point. POINTS sets the active range from 1 to 64 without discarding the position, gain, mute, or solo state of temporarily inactive points. The MIXER page provides gain, mute, and solo controls in four 16-point banks.

Scenes and Automation

MOTION selects the motion engine. The STYLE menu directly below it shows only behaviors that belong to that engine. Editing a motion or physics trim changes the current style to CUSTOM without changing the selected motion engine.

Active Points and every point's azimuth, elevation, distance, gain, mute, and solo are exposed to REAPER automation. All 64 point parameter IDs remain available even when their points are outside the active range, so prepared scenes can be edited before those lanes are activated. GUI-only selection is not meant to be an automation target.

Spatial Score Automation

The Spatial Score browser utility in s3g-mc can compose larger point-motion scores outside REAPER. Export the Spatial Score JSON, focus an instance of s3g Ambi Encoder Point, set MOTION to OFF / MANUAL, then run Load Spatial Score JSON from s3g-mc. The loader writes the score's azimuth, elevation, and distance lanes to the matching Encoder Point parameters; if the score contains more point paths than the plugin exposes, the first available points are used.

Motion and Physics Controls

The MOTION panel shapes all internal motion styles. The collision, impact, and Geist controls are primarily meaningful in PHYS. Physics styles use a persistent point world with boundary rebound, collision events, optional nearest-neighbor springs, and an automatable POLTER / Poltergeist cue-ball source.

POLTER also dissolves neighbor physics. At 0%, a scene keeps its normal nearest-neighbor behavior. At 100%, no nearest-neighbor springs are applied, so motion is driven by the Geist, point collisions, boundary rebound, and scene forces.

Reading Geist Motion

The Geist source is shown as a small grayscale marker in the FIELD view. The three-ring sphere around it is the active 3D influence radius, not a flat screen overlay. When a point enters that sphere, the force begins at the sphere edge and increases inward. If HEMISPHERE is set to upper hemisphere, the Geist path is also constrained upward and the lower half of its influence sphere is clipped from the view.

• POLTER sets Geist strength and dissolves neighbor bonds.
• G-RATE sets Geist movement speed.
• G-REACH sets how far the Geist travels through the 3D point field, including elevation travel.
• G-RAD sets the Geist influence radius.
• G-CHAOS adds irregularity and extends bond-break time.

When the Geist strikes a point, local bonds are erased for at least two seconds, scaling up toward five seconds with higher POLTER, G-CHAOS, and strike energy. Broken bonds disappear from the nearest-neighbor drawing and fade back as they heal. Released points get a subtle dashed outline.

Collision and strike energy change outline and link brightness, but point size stays stable so the display does not imply gain or distance changes.

SCALE expands or compresses the animated motion reach. Scene presets default to 1.0, which keeps animated points inside the normal unit sphere. Values above 1.0 deliberately let the scene move farther outward. This is separate from camera zoom: SCALE changes animated point positions used by the encoder, while camera zoom changes only the view.

HEMISPHERE is global. When set to upper hemisphere, points and auxiliary motion sources are constrained to non-negative elevation.

Order and Routing

The plugin exposes fixed 64-channel input and output buses, matching the other encoders. POINTS determines how many leading mono input lanes are encoded, while ORDER selects 1OA through 7OA; inactive inputs are ignored and output channels above the selected order are cleared. Keep the REAPER track and pin connectors at 64 channels, and place decoding or field analysis after the encoder.