Graceful-ish handling of more than 1 perception camera for visualization

TestProjects/PerceptionURP/Assets/Scenes/SampleScene.unity

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com.unity.perception/Runtime/GroundTruth/Labelers/BoundingBoxLabeler.cs

                 if (!CaptureOptions.useAsyncReadbackIfSupported && frameCount != Time.frameCount) 
                     Debug.LogWarning("Not on current frame: " + frameCount + "(" + Time.frameCount + ")");
 
-                if (visualizationEnabled) 
+                if (perceptionCamera.visualizationEnabled && visualizationEnabled)
                 {
                     Visualize();
                 }

com.unity.perception/Runtime/GroundTruth/Labelers/ObjectCountLabeler.cs

                         count = counts[i]
                     };
 
-                    if (visualizationEnabled)
+                    if (visualizationEnabled && perceptionCamera.visualizationEnabled)
                     {
                         if (entryToLabelMap == null) entryToLabelMap = new Dictionary<string, string>();
 

com.unity.perception/Runtime/GroundTruth/Labelers/RenderedObjectInfoLabeler.cs

                         visible_pixels = objectInfo.pixelCount
                     };
 
-                    if (visualizationEnabled)
+                    if (visualizationEnabled && perceptionCamera.visualizationEnabled)
                     {
                         if (entryToLabelMap == null) entryToLabelMap = new Dictionary<string, string>();
 

com.unity.perception/Runtime/GroundTruth/Labelers/SemanticSegmentationLabeler.cs

 
             var asyncRequest = Manager.Instance.CreateRequest<AsyncRequest<AsyncSemanticSegmentationWrite>>();
             
-            if (visualizationEnabled)
+            if (visualizationEnabled && perceptionCamera.visualizationEnabled)
                 VisualizeSegmentationTexture(data, targetTexture);
 
             imageReadback?.Invoke(new ImageReadbackEventArgs

com.unity.perception/Runtime/GroundTruth/PerceptionCamera.cs

-using System;
+using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
         bool m_GroundTruthRendererFeatureRun;
 
         private static Camera visualizationCamera;
+
+        /// <summary>
+        /// Should the labeling visualization routines run for this camera. This will only
+        /// be set to false if there is more than one camera in the scene, and this is
+        /// not considered the active camera.
+        /// </summary>
+        bool m_VisualizationEnabled = true;
+        public bool visualizationEnabled 
+        { 
+            get
+            {
+                return m_VisualizationEnabled;
+            }
+        }
 
         /// <summary>
         /// The <see cref="SensorHandle"/> associated with this camera. Use this to report additional annotations and metrics at runtime.
 
         void Start()
         {
-            SetupVisualizationCamera();
+            var cam = GetComponent<Camera>();
+            cam.enabled = false;
+
+            SetupVisualizationCamera(cam);
-        void SetupVisualizationCamera()
+        bool SetupVisualizationCamera(Camera cam)
+            {
-
-            var cam = GetComponent<Camera>();
-            cam.enabled = false;
+                m_VisualizationEnabled = false;
+                return false;
+            }
 
             // set up to render to a render texture instead of the screen
             var visualizationRenderTexture = new RenderTexture(new RenderTextureDescriptor(cam.pixelWidth, cam.pixelHeight, UnityEngine.Experimental.Rendering.GraphicsFormat.R8G8B8A8_UNorm, 8));
             rect.pivot = new Vector2(0.5f, 0.5f);
             rect.offsetMax = Vector2.zero;
             rect.offsetMin = Vector2.zero;
+
+            return true;
         }
 
         void CheckForRendererFeature(ScriptableRenderContext context, Camera camera)