add clean-up flag for benchmark

SeeSharp/Experiments/Benchmark.cs

@@ -59,7 +59,9 @@ void RunScene(SceneConfig sceneConfig, string format, bool skipReference) {
 
         experiment.OnStartScene(scene, dir, sceneConfig.MinDepth, sceneConfig.MaxDepth);
         var methods = experiment.MakeMethods();
-        foreach (var method in methods) {
+        for (int i = 0; i < methods.Count; ++i) {
+            var method = methods[i];
+
             string path = Path.Join(dir, method.Name);
 
             Logger.Log($"Rendering {sceneConfig.Name} with {method.Name}");
@@ -78,6 +80,11 @@ void RunScene(SceneConfig sceneConfig, string format, bool skipReference) {
             scene.FrameBuffer.MetaData["RayStats"] = scene.Raytracer.Stats;
             scene.FrameBuffer.MetaData["ShadeStats"] = ShadingStats.Current;
             scene.FrameBuffer.WriteToFile();
+
+            if (experiment.DeleteMethodAfterRun) {
+                methods.RemoveAt(i);
+                i--;
+            }
         }
         experiment.OnDoneScene(scene, dir, sceneConfig.MinDepth, sceneConfig.MaxDepth);
     }

SeeSharp/Experiments/Experiment.cs

@@ -29,6 +29,12 @@ public Method(string name, Integrator integrator) {
         }
     }
 
+    /// <summary>
+    /// If true, the Benchmark will drop the method reference after execution. This allows costly integrator
+    /// data to be freed as soon as possible. Disadvantage: all integrator state will be lost. The default is false.
+    /// </summary>
+    public virtual bool DeleteMethodAfterRun => false;
+
     /// <summary>
     /// Factory function for the methods.
     /// </summary>