fix: handle errors when capturing Render results to files (#461)

Author: sindharta

Editor/Scripts/Features/RenderCache/RenderCachePlayableAssetInspector.cs

@@ -275,8 +275,9 @@ internal static IEnumerator UpdateRenderCacheCoroutine(PlayableDirector director
             default:                          outputExt = "png"; break;;
         }
 
-        bool cancelled = false;
-        while (!cancelled) {            
+        bool cancelled      = false;
+        bool captureSuccessful = true;
+        while (!cancelled && captureSuccessful) {
 
             //Always recalculate from start to avoid floating point errors
             double directorTime = timelineClip.start + (fileCounter * timePerFrame);
@@ -305,10 +306,8 @@ internal static IEnumerator UpdateRenderCacheCoroutine(PlayableDirector director
 
                 //Unload texture because it may be overwritten
                 StreamingImageSequencePlugin.UnloadImageAndNotify(outputFilePath);
-                renderCapturer.CaptureToFile(outputFilePath, outputFormat);
-                
+                captureSuccessful = renderCapturer.TryCaptureToFile(outputFilePath, outputFormat);
             } 
-            Assert.IsTrue(File.Exists(outputFilePath));
 
             ++fileCounter;        
             cancelled = EditorUtility.DisplayCancelableProgressBar(
@@ -336,6 +335,10 @@ internal static IEnumerator UpdateRenderCacheCoroutine(PlayableDirector director
 
             }            
         }
+
+        if (!captureSuccessful) {
+            EditorUtility.DisplayDialog("Streaming Image Sequence", "Capturing failed", "Ok");
+        }
 
         //Notify
         FolderContentsChangedNotifier.GetInstance().Notify(outputFolder);        

Runtime/Scripts/Features/RenderCache/Components/BaseRenderCapturer.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Collections;
 using System.IO;
+using JetBrains.Annotations;
 using Unity.FilmInternalUtilities;
 using UnityEngine;
 
@@ -38,13 +39,17 @@ public abstract class BaseRenderCapturer : MonoBehaviour {
     public Texture GetInternalTexture() { return m_rt;}
 
     /// <summary>
-    /// Capture the contents of RenderTexture into file
+    /// Capture the contents of RenderTexture to file
     /// </summary>
     /// <param name="outputFilePath">The path of the file</param>
     /// <param name="outputFormat">The output file format</param>
-    public void CaptureToFile(string outputFilePath, RenderCacheOutputFormat outputFormat = RenderCacheOutputFormat.PNG) 
+    /// <returns>True if successful, false otherwise</returns>
+    public bool TryCaptureToFile(string outputFilePath, RenderCacheOutputFormat outputFormat = RenderCacheOutputFormat.PNG) 
     {
         RenderTexture rt = UpdateRenderTextureV();
+        if (null == rt)
+            return false;
+        
         TextureFormat textureFormat = TextureFormat.RGBA32;
         bool isPNG = true;
         if (RenderCacheOutputFormat.EXR == outputFormat) {
@@ -56,14 +61,29 @@ public void CaptureToFile(string outputFilePath, RenderCacheOutputFormat outputF
         if (!writeSuccess) {
             Debug.LogError($"[SIS] Can't write to file: {outputFilePath}." + Environment.NewLine);             
         }
+
+        return true;
     }
 
+    /// <summary>
+    /// Capture the contents of RenderTexture to file
+    /// </summary>
+    /// <param name="outputFilePath">The path of the file</param>
+    /// <param name="outputFormat">The output file format</param>    
+    [Obsolete("Replaced by TryCaptureToFile()")]
+    public void CaptureToFile(string outputFilePath, RenderCacheOutputFormat outputFormat = RenderCacheOutputFormat.PNG) 
+    {
+        //[TODO-sin: 2022-9-26] Remove CaptureToFile() function in 0.17.x-preview
+        TryCaptureToFile(outputFilePath, outputFormat);
+    }
+    
 //----------------------------------------------------------------------------------------------------------------------
 
     /// <summary>
     /// Updates the render texture used for the capturing process
     /// </summary>
-    /// <returns>The updated render texture</returns>
+    /// <returns>The updated render texture if successful, null otherwise</returns>
+    [CanBeNull]
     protected abstract RenderTexture UpdateRenderTextureV();
 
 

Runtime/Scripts/Features/RenderCache/Components/PencilLineRenderCapturer.cs

@@ -81,7 +81,8 @@ public override void EndCaptureV() {
     protected override RenderTexture UpdateRenderTextureV() {
 #if AT_USE_PENCILLINE
         PencilLineRenderer lineRenderer = m_pencilLineEffect.PencilRenderer;
-        Assert.IsNotNull(lineRenderer);
+        if (null == lineRenderer)
+            return null;
         Graphics.Blit(lineRenderer.Texture, m_rt);
 #endif
         return m_rt;