0030476: Visualization, Path Tracing - Adaptive Screen Sampling leads to unstable results

OpenGl_View::runPathtrace() has been extended with alternative multi-pass
Adaptive Screen Sampling mode, not relying on atomic floating point operations.
Although atomic operations on floats allows single-pass rendering,
such operations leads to instability in case of different calculation order.
Atomic float operations are also currently supported only by single GPU vendor.

Fixed GLSL compilation on Intel drivers (follow ARB_shader_image_load_store
specs rather than EXT_shader_image_load_store).

Graphic3d_RenderingParams::AdaptiveScreenSamplingAtomic option has been added
to activate 1-pass Adaptive Screen Sampling mode when supported by hardware.

vfps command has been extended with -duration argument allowing to limit command execution time.
vactivate command has been extended with -noUpdate argument.

src/ViewerTest/ViewerTest_ViewerCommands.cxx

@@ -1264,38 +1264,40 @@ TCollection_AsciiString FindViewIdByWindowHandle(const Aspect_Handle theWindowHa
 }
 #endif
 
-//==============================================================================
-//function : ActivateView
-//purpose  : Make the view active
-//==============================================================================
-
-void ActivateView (const TCollection_AsciiString& theViewName)
+//! Make the view active
+void ActivateView (const TCollection_AsciiString& theViewName,
+                   Standard_Boolean theToUpdate = Standard_True)
 {
   const Handle(V3d_View) aView = ViewerTest_myViews.Find1(theViewName);
-  if (!aView.IsNull())
+  if (aView.IsNull())
   {
-    Handle(AIS_InteractiveContext) anAISContext = FindContextByView(aView);
-    if (!anAISContext.IsNull())
-    {
-      if (!ViewerTest::CurrentView().IsNull())
-      {
-        TCollection_AsciiString aTitle("3D View - ");
-        aTitle = aTitle + ViewerTest_myViews.Find2 (ViewerTest::CurrentView());
-        SetWindowTitle (ViewerTest::CurrentView()->Window(), aTitle.ToCString());
-      }
+    return;
+  }
 
-      ViewerTest::CurrentView (aView);
-      ViewerTest::SetAISContext (anAISContext);
-      TCollection_AsciiString aTitle = TCollection_AsciiString("3D View - ") + theViewName + "(*)";
+  Handle(AIS_InteractiveContext) anAISContext = FindContextByView(aView);
+  if (!anAISContext.IsNull())
+  {
+    if (!ViewerTest::CurrentView().IsNull())
+    {
+      TCollection_AsciiString aTitle("3D View - ");
+      aTitle = aTitle + ViewerTest_myViews.Find2 (ViewerTest::CurrentView());
       SetWindowTitle (ViewerTest::CurrentView()->Window(), aTitle.ToCString());
+    }
+
+    ViewerTest::CurrentView (aView);
+    ViewerTest::SetAISContext (anAISContext);
+    TCollection_AsciiString aTitle = TCollection_AsciiString("3D View - ") + theViewName + "(*)";
+    SetWindowTitle (ViewerTest::CurrentView()->Window(), aTitle.ToCString());
 #if defined(_WIN32)
-      VT_GetWindow() = Handle(WNT_Window)::DownCast(ViewerTest::CurrentView()->Window());
+    VT_GetWindow() = Handle(WNT_Window)::DownCast(ViewerTest::CurrentView()->Window());
 #elif defined(__APPLE__) && !defined(MACOSX_USE_GLX)
-      VT_GetWindow() = Handle(Cocoa_Window)::DownCast(ViewerTest::CurrentView()->Window());
+    VT_GetWindow() = Handle(Cocoa_Window)::DownCast(ViewerTest::CurrentView()->Window());
 #else
-      VT_GetWindow() = Handle(Xw_Window)::DownCast(ViewerTest::CurrentView()->Window());
+    VT_GetWindow() = Handle(Xw_Window)::DownCast(ViewerTest::CurrentView()->Window());
 #endif
-      SetDisplayConnection(ViewerTest::CurrentView()->Viewer()->Driver()->GetDisplayConnection());
+    SetDisplayConnection(ViewerTest::CurrentView()->Viewer()->Driver()->GetDisplayConnection());
+    if (theToUpdate)
+    {
       ViewerTest::CurrentView()->Redraw();
     }
   }
@@ -1348,16 +1350,8 @@ void ViewerTest::RemoveView (const TCollection_AsciiString& theViewName, const S
     }
     else
     {
-      Handle(V3d_View) anEmptyView;
-#if defined(_WIN32) || defined(__WIN32__)
-      Handle(WNT_Window) anEmptyWindow;
-#elif defined(__APPLE__) && !defined(MACOSX_USE_GLX)
-      Handle(Cocoa_Window) anEmptyWindow;
-#else
-      Handle(Xw_Window) anEmptyWindow;
-#endif
-      VT_GetWindow() = anEmptyWindow;
-      ViewerTest::CurrentView (anEmptyView);
+      VT_GetWindow().Nullify();
+      ViewerTest::CurrentView (Handle(V3d_View)());
       if (isContextRemoved)
       {
         Handle(AIS_InteractiveContext) anEmptyContext;
@@ -1490,45 +1484,64 @@ static int VClose (Draw_Interpretor& /*theDi*/,
 
 static int VActivate (Draw_Interpretor& theDi, Standard_Integer theArgsNb, const char** theArgVec)
 {
-  if (theArgsNb > 2)
-  {
-    theDi << theArgVec[0] << ": wrong number of command arguments.\n"
-    << "Usage: " << theArgVec[0] << " ViewID\n";
-    return 1;
-  }
-  if(theArgsNb == 1)
+  if (theArgsNb == 1)
   {
     theDi.Eval("vviewlist");
     return 0;
   }
 
-  TCollection_AsciiString aNameString(theArgVec[1]);
-  if ( strcasecmp( aNameString.ToCString(), "NONE" ) == 0 )
+  TCollection_AsciiString aNameString;
+  Standard_Boolean toUpdate = Standard_True;
+  Standard_Boolean toActivate = Standard_True;
+  for (Standard_Integer anArgIter = 1; anArgIter < theArgsNb; ++anArgIter)
   {
-    TCollection_AsciiString aTitle("3D View - ");
-    aTitle = aTitle + ViewerTest_myViews.Find2(ViewerTest::CurrentView());
-    SetWindowTitle (ViewerTest::CurrentView()->Window(), aTitle.ToCString());
-    Handle(V3d_View) anEmptyView;
-#if defined(_WIN32) || defined(__WIN32__)
-    Handle(WNT_Window) anEmptyWindow;
-#elif defined(__APPLE__) && !defined(MACOSX_USE_GLX)
-    Handle(Cocoa_Window) anEmptyWindow;
-#else
-    Handle(Xw_Window) anEmptyWindow;
-#endif
-    VT_GetWindow() = anEmptyWindow;
-    ViewerTest::CurrentView (anEmptyView);
-    ViewerTest::ResetEventManager();
-    theDi << theArgVec[0] << ": all views are inactive\n";
-    return 0;
+    TCollection_AsciiString anArg (theArgVec[anArgIter]);
+    anArg.LowerCase();
+    if (toUpdate
+     && anArg == "-noupdate")
+    {
+      toUpdate = Standard_False;
+    }
+    else if (toActivate
+          && aNameString.IsEmpty()
+          && anArg == "none")
+    {
+      TCollection_AsciiString aTitle("3D View - ");
+      aTitle = aTitle + ViewerTest_myViews.Find2(ViewerTest::CurrentView());
+      SetWindowTitle (ViewerTest::CurrentView()->Window(), aTitle.ToCString());
+      VT_GetWindow().Nullify();
+      ViewerTest::CurrentView (Handle(V3d_View)());
+      ViewerTest::ResetEventManager();
+      theDi << theArgVec[0] << ": all views are inactive\n";
+      toActivate = Standard_False;
+    }
+    else if (toActivate
+          && aNameString.IsEmpty())
+    {
+      aNameString = theArgVec[anArgIter];
+    }
+    else
+    {
+      std::cout << "Syntax error at '" << theArgVec[anArgIter] << "'\n";
+      return 1;
+    }
   }
 
-  ViewerTest_Names aViewNames(aNameString);
+  if (!toActivate)
+  {
+    return 0;
+  }
+  else if (aNameString.IsEmpty())
+  {
+    std::cout << "Syntax error: wrong number of arguments\n";
+    return 1;
+  }
 
   // Check if this view exists in the viewer with the driver
+  ViewerTest_Names aViewNames (aNameString);
   if (!ViewerTest_myViews.IsBound1(aViewNames.GetViewName()))
   {
-    theDi << "Wrong view name\n";
+    theDi << "Syntax error: wrong view name '" << aNameString << "'\n";
     return 1;
   }
 
@@ -1539,7 +1552,7 @@ static int VActivate (Draw_Interpretor& theDi, Standard_Integer theArgsNb, const
     return 0;
   }
 
-  ActivateView (aViewNames.GetViewName());
+  ActivateView (aViewNames.GetViewName(), toUpdate);
   return 0;
 }
 
@@ -5556,11 +5569,39 @@ static int VFps (Draw_Interpretor& theDI,
     return 1;
   }
 
-  Standard_Integer aFramesNb = (theArgNb > 1) ? Draw::Atoi(theArgVec[1]) : 100;
-  if (aFramesNb <= 0)
+  Standard_Integer aFramesNb = -1;
+  Standard_Real aDuration = -1.0;
+  for (Standard_Integer anArgIter = 1; anArgIter < theArgNb; ++anArgIter)
   {
-    std::cerr << "Incorrect arguments!\n";
-    return 1;
+    TCollection_AsciiString anArg (theArgVec[anArgIter]);
+    anArg.LowerCase();
+    if (aDuration < 0.0
+     && anArgIter + 1 < theArgNb
+     && (anArg == "-duration"
+      || anArg == "-dur"
+      || anArg == "-time"))
+    {
+      aDuration = Draw::Atof (theArgVec[++anArgIter]);
+    }
+    else if (aFramesNb < 0
+          && anArg.IsIntegerValue())
+    {
+      aFramesNb = anArg.IntegerValue();
+      if (aFramesNb <= 0)
+      {
+        std::cerr << "Syntax error at '" << anArg << "'\n";
+        return 1;
+      }
+    }
+    else
+    {
+      std::cerr << "Syntax error at '" << anArg << "'\n";
+      return 1;
+    }
+  }
+  if (aFramesNb < 0 && aDuration < 0.0)
+  {
+    aFramesNb = 100;
   }
 
   // the time is meaningless for first call
@@ -5570,35 +5611,39 @@ static int VFps (Draw_Interpretor& theDI,
   // redraw view in loop to estimate average values
   OSD_Timer aTimer;
   aTimer.Start();
-  for (Standard_Integer anInter = 0; anInter < aFramesNb; ++anInter)
+  Standard_Integer aFrameIter = 1;
+  for (;; ++aFrameIter)
   {
     aView->Redraw();
+    if ((aFramesNb > 0
+      && aFrameIter >= aFramesNb)
+     || (aDuration > 0.0
+      && aTimer.ElapsedTime() >= aDuration))
+    {
+      break;
+    }
   }
   aTimer.Stop();
   Standard_Real aCpu;
   const Standard_Real aTime = aTimer.ElapsedTime();
   aTimer.OSD_Chronometer::Show (aCpu);
 
-  const Standard_Real aFpsAver = Standard_Real(aFramesNb) / aTime;
-  const Standard_Real aCpuAver = aCpu / Standard_Real(aFramesNb);
+  const Standard_Real aFpsAver = Standard_Real(aFrameIter) / aTime;
+  const Standard_Real aCpuAver = aCpu / Standard_Real(aFrameIter);
 
   // return statistics
   theDI << "FPS: " << aFpsAver << "\n"
         << "CPU: " << (1000.0 * aCpuAver) << " msec\n";
 
   // compute additional statistics in ray-tracing mode
-  Graphic3d_RenderingParams& aParams = aView->ChangeRenderingParams();
-
+  const Graphic3d_RenderingParams& aParams = aView->RenderingParams();
   if (aParams.Method == Graphic3d_RM_RAYTRACING)
   {
-    Standard_Integer aSizeX;
-    Standard_Integer aSizeY;
-
-    aView->Window()->Size (aSizeX, aSizeY);
+    Graphic3d_Vec2i aWinSize (0, 0);
+    aView->Window()->Size (aWinSize.x(), aWinSize.y());
 
     // 1 shadow ray and 1 secondary ray pew each bounce
-    const Standard_Real aMRays = aSizeX * aSizeY * aFpsAver * aParams.RaytracingDepth * 2 / 1.0e6f;
-
+    const Standard_Real aMRays = aWinSize.x() * aWinSize.y() * aFpsAver * aParams.RaytracingDepth * 2 / 1.0e6f;
     theDI << "MRays/sec (upper bound): " << aMRays << "\n";
   }
 
@@ -10797,6 +10842,22 @@ static Standard_Integer VRenderParams (Draw_Interpretor& theDI,
       }
       aParams.AdaptiveScreenSampling = toEnable;
     }
+    else if (aFlag == "-issatomic")
+    {
+      if (toPrint)
+      {
+        theDI << (aParams.AdaptiveScreenSamplingAtomic ? "on" : "off") << " ";
+        continue;
+      }
+
+      Standard_Boolean toEnable = Standard_True;
+      if (++anArgIter < theArgNb
+      && !ViewerTest::ParseOnOff (theArgVec[anArgIter], toEnable))
+      {
+        --anArgIter;
+      }
+      aParams.AdaptiveScreenSamplingAtomic = toEnable;
+    }
     else if (aFlag == "-issd")
     {
       if (toPrint)
@@ -12279,7 +12340,7 @@ void ViewerTest::ViewerCommands(Draw_Interpretor& theCommands)
     " the current context is not removed.",
     __FILE__,VClose,group);
   theCommands.Add("vactivate" ,
-    "view_id"
+    "vactivate view_id [-noUpdate]"
     " - activates view(viewer window) defined by its view_id",
     __FILE__,VActivate,group);
   theCommands.Add("vviewlist",
@@ -12492,7 +12553,7 @@ void ViewerTest::ViewerCommands(Draw_Interpretor& theCommands)
     "\n\t\t: Converts the given coordinates to window/view/model space.",
     __FILE__, VConvert, group);
   theCommands.Add ("vfps",
-    "vfps [framesNb=100] : estimate average frame rate for active view",
+    "vfps [framesNb=100] [-duration seconds] : estimate average frame rate for active view",
     __FILE__, VFps, group);
   theCommands.Add ("vgldebug",
             "vgldebug [-sync {0|1}] [-debug {0|1}] [-glslWarn {0|1}]"

src/ViewerTest/ViewerTest_ViewerCommands_1.mm

@@ -37,7 +37,8 @@
 @interface Cocoa_WindowController : NSObject <NSWindowDelegate>
 @end
 
-extern void ActivateView (const TCollection_AsciiString& theViewName);
+extern void ActivateView (const TCollection_AsciiString& theViewName,
+                          Standard_Boolean theToUpdate = Standard_True);
 extern void VT_ProcessExpose();
 extern void VT_ProcessConfigure();
 extern void VT_ProcessKeyPress (const char* theBuffer);