Add magnetic field vector (#1416)

gui/src/components/widgets/IMUVisualizerWidget.tsx

@@ -28,12 +28,20 @@ export function TrackerModel({ model }: { model: string }) {
 function SceneRenderer({
   quat,
   vec,
+  mag,
   model,
 }: {
   quat: QuatObject;
   vec: Vector3Object;
+  mag: Vector3Object;
   model: string;
 }) {
+    const magDir = new Vector3(mag.x, mag.y, mag.z);
+    const magLen = magDir.length();
+    const magMag = Math.sqrt(magLen / 100); // normalize magnituge
+    if (magLen > 0)
+      magDir.multiplyScalar(1/ magLen);
+
   return (
     <Canvas
       className="container"
@@ -61,6 +69,14 @@ function SceneRenderer({
           Math.sqrt(Vector3FromVec3fT(vec).length()) * 2,
         ]}
       />
+      <arrowHelper
+        args={[
+          magDir,
+          magDir.clone().multiplyScalar(-magMag),
+          2 * magMag,
+          THREE.Color.NAMES.aqua,
+        ]}
+      />
 
       <mesh position={[0, -3, 0]} rotation={[-Math.PI / 2, 0, 0]}>
         <planeGeometry args={[50, 50, 10, 10]} />
@@ -102,6 +118,9 @@ export function IMUVisualizerWidget({ tracker }: { tracker: TrackerDataT }) {
     tracker?.linearAcceleration ||
     tracker?.rawAcceleration ||
     new THREE.Vector3();
+    const mag =
+        tracker?.rawMagneticVector ||
+        new THREE.Vector3();
 
   return (
     <div className="bg-background-70 flex flex-col p-3 rounded-lg gap-2">
@@ -143,6 +162,17 @@ export function IMUVisualizerWidget({ tracker }: { tracker: TrackerDataT }) {
         </div>
       )}
 
+      {tracker.rawMagneticVector && (
+        <div className="flex justify-between">
+          <Typography color="secondary">
+            {l10n.getString('tracker-infos-magnetometer')}
+          </Typography>
+          <Typography>
+            {formatVector3(tracker.rawMagneticVector, 1)}
+          </Typography>
+        </div>
+      )}
+
       {!enabled && (
         <Button
           variant="secondary"
@@ -175,6 +205,7 @@ export function IMUVisualizerWidget({ tracker }: { tracker: TrackerDataT }) {
             <SceneRenderer
               quat={{ ...quat }}
               vec={{ ...vec }}
+              mag={{ ...mag }}
               model={
                 isExtension ? '/models/extension.gltf' : '/models/tracker.gltf'
               }

gui/src/hooks/datafeed-config.ts

@@ -17,6 +17,7 @@ export function useDataFeedConfig() {
   trackerData.rotationReferenceAdjusted = true;
   trackerData.rotationIdentityAdjusted = true;
   trackerData.tps = true;
+  trackerData.rawMagneticVector = true;
 
   const dataMask = new DeviceDataMaskT();
   dataMask.deviceData = true;

server/core/src/main/java/dev/slimevr/protocol/datafeed/DataFeedBuilder.java

@@ -3,6 +3,7 @@ package dev.slimevr.protocol.datafeed;
 import com.google.flatbuffers.FlatBufferBuilder;
 import dev.slimevr.tracking.trackers.Device;
 import dev.slimevr.tracking.trackers.Tracker;
+import dev.slimevr.tracking.trackers.udp.MagnetometerStatus;
 import dev.slimevr.tracking.trackers.udp.UDPDevice;
 import io.github.axisangles.ktmath.Quaternion;
 import io.github.axisangles.ktmath.Vector3;
@@ -80,6 +81,16 @@ public class DataFeedBuilder {
 		return TrackerId.endTrackerId(fbb);
 	}
 
+	public static int createVec3(FlatBufferBuilder fbb, Vector3 vec) {
+		return Vec3f
+			.createVec3f(
+				fbb,
+				vec.getX(),
+				vec.getY(),
+				vec.getZ()
+			);
+	}
+
 	public static int createQuat(FlatBufferBuilder fbb, Quaternion quaternion) {
 		return Quat
 			.createQuat(
@@ -146,14 +157,7 @@ public class DataFeedBuilder {
 	}
 
 	public static int createTrackerPosition(FlatBufferBuilder fbb, Tracker tracker) {
-		Vector3 pos = tracker.getPosition();
-		return Vec3f
-			.createVec3f(
-				fbb,
-				pos.getX(),
-				pos.getY(),
-				pos.getZ()
-			);
+		return createVec3(fbb, tracker.getPosition());
 	}
 
 	public static int createTrackerRotation(FlatBufferBuilder fbb, Tracker tracker) {
@@ -161,14 +165,11 @@ public class DataFeedBuilder {
 	}
 
 	public static int createTrackerAcceleration(FlatBufferBuilder fbb, Tracker tracker) {
-		Vector3 accel = tracker.getAcceleration();
-		return Vec3f
-			.createVec3f(
-				fbb,
-				accel.getX(),
-				accel.getY(),
-				accel.getZ()
-			);
+		return createVec3(fbb, tracker.getAcceleration());
+	}
+
+	public static int createTrackerMagneticVector(FlatBufferBuilder fbb, Tracker tracker) {
+		return createVec3(fbb, tracker.getMagVector());
 	}
 
 	public static int createTrackerTemperature(FlatBufferBuilder fbb, Tracker tracker) {
@@ -233,6 +234,9 @@ public class DataFeedBuilder {
 		if (mask.getTps()) {
 			TrackerData.addTps(fbb, (int) tracker.getTps());
 		}
+		if (mask.getRawMagneticVector() && tracker.getMagStatus() == MagnetometerStatus.ENABLED) {
+			TrackerData.addRawMagneticVector(fbb, createTrackerMagneticVector(fbb, tracker));
+		}
 
 		return TrackerData.endTrackerData(fbb);
 	}

server/core/src/main/java/dev/slimevr/tracking/trackers/Tracker.kt

@@ -92,6 +92,7 @@ class Tracker @JvmOverloads constructor(
 	private var timeAtLastUpdate: Long = System.currentTimeMillis()
 	private var _rotation = Quaternion.IDENTITY
 	private var _acceleration = Vector3.NULL
+	private var _magVector = Vector3.NULL
 	var position = Vector3.NULL
 	val resetsHandler: TrackerResetsHandler = TrackerResetsHandler(this)
 	val filteringHandler: TrackerFilteringHandler = TrackerFilteringHandler()
@@ -424,6 +425,22 @@ class Tracker @JvmOverloads constructor(
 		}
 	}
 
+	/**
+	 * Gets the magnetic field vector, in mGauss.
+	 */
+	fun getMagVector() = if (needsReset) {
+		resetsHandler.getReferenceAdjustedAccel(_rotation, _magVector)
+	} else {
+		_magVector
+	}
+
+	/**
+	 * Sets the magnetic field vector.
+	 */
+	fun setMagVector(vec: Vector3) {
+		this._magVector = vec
+	}
+
 	/**
 	 * Gets the current TPS of the tracker
 	 */