WebXRManager: Disable left eye layer for right eye camera and vice versa (#31437)

src/renderers/webxr/WebXRManager.js

@@ -722,9 +722,10 @@ class WebXRManager extends EventDispatcher {
 
 			}
 
-			cameraL.layers.mask = camera.layers.mask | 0b010;
-			cameraR.layers.mask = camera.layers.mask | 0b100;
-			cameraXR.layers.mask = cameraL.layers.mask | cameraR.layers.mask;
+			// inherit camera layers and enable eye layers (1 = left, 2 = right)
+			cameraXR.layers.mask = camera.layers.mask | 0b110;
+			cameraL.layers.mask = cameraXR.layers.mask & 0b011;
+			cameraR.layers.mask = cameraXR.layers.mask & 0b101;
 
 			const parent = camera.parent;
 			const cameras = cameraXR.cameras;