SceneView : Add included purposes to the drawingMode menu

Changes.md

@@ -4,6 +4,9 @@
 Improvements
 ------------
 
+- Viewer : Added per-purpose control over which locations are shown in the viewer, according to their `usd:purpose` attribute.
+  - The Drawing Mode dropdown menu can be used to to choose the visible purposes.
+  - The default purposes can be specified in a startup file using `Gaffer.Metadata.registerValue( GafferSceneUI.SceneView, "drawingMode.includedPurposes.value", "userDefault", IECore.StringVectorData( [ "default", "proxy" ] ) )`.
 - StandardOptions : Added `includedPurposes` plug, to control which locations are included in a render based on the value of their `usd:purpose` attribute.
 
 API

python/GafferSceneUI/SceneViewUI.py

@@ -376,6 +376,34 @@ def __menuDefinition( self ) :
 
 		m.append( "/ComponentsDivider", { "divider" : True } )
 
+		includedPurposes = self.getPlug()["includedPurposes"]["value"].getValue()
+		includedPurposesEnabled = self.getPlug()["includedPurposes"]["enabled"].getValue()
+		allPurposes = [ "default", "render", "proxy", "guide" ]
+		for purpose in allPurposes :
+			newPurposes = IECore.StringVectorData( [
+				p for p in allPurposes
+				if
+				( p != purpose and p in includedPurposes ) or ( p == purpose and p not in includedPurposes )
+			] )
+			m.append(
+				"/Purposes/{}".format( purpose.capitalize() ),
+				{
+					"checkBox" : purpose in includedPurposes,
+					"active" : includedPurposesEnabled,
+					"command" : functools.partial( self.getPlug()["includedPurposes"]["value"].setValue, newPurposes ),
+				}
+			)
+			m.append( "/Purposes/SceneDivider", { "divider" : True } )
+			m.append(
+				"/Purposes/From Scene",
+				{
+					"checkBox" : not includedPurposesEnabled,
+					"command" : lambda checked : self.getPlug()["includedPurposes"]["enabled"].setValue( not checked ),
+				}
+			)
+
+		m.append( "/PurposesDivider", { "divider" : True } )
+
 		lightDrawingModePlug = self.getPlug()["light"]["drawingMode"]
 		for mode in ( "wireframe", "color", "texture" ) :
 			m.append(

src/GafferSceneUI/SceneView.cpp

@@ -289,23 +289,9 @@ class SceneView::DrawingMode : public Signals::Trackable
 		DrawingMode( SceneView *view )
 			:	m_view( view )
 		{
-			// We can implement many drawing mode controls via render options.
-			// They simply modify the state used to render existing
-			// renderables. Visualisers however, may generate different
-			// renderables all together and so we need to modify the in-scene
-			// attribute values rather than any renderer option, which will
-			// cause the visualisers to be re-evaluated. We use a general
-			// purpose CustomAttributes preprocessor to set globals attributes
-			// with the desired values.  This allows them to be overridden at
-			// specific locations in the user's graph if desired.
 
-			// Global attributes preprocessor
-
-			m_preprocessor = new CustomAttributes();
-			m_preprocessor->globalPlug()->setValue( true );
-			CompoundDataPlug *attr = m_preprocessor->attributesPlug();
-
-			// View plugs controlling renderer options
+			// Plugs controlling OpenGL render options. We use these to
+			// drive `SceneGadget::setOpenGLOptions()` directly.
 
 			ValuePlugPtr drawingMode = new ValuePlug( "drawingMode" );
 			m_view->addChild( drawingMode );
@@ -323,9 +309,34 @@ class SceneView::DrawingMode : public Signals::Trackable
 			drawingMode->addChild( points );
 			points->addChild( new BoolPlug( "useGLPoints", Plug::In, true ) );
 
-			// View plugs controlling attribute values
+			// A preprocessor which modifies the scene before it is displayed by
+			// the SceneGadget. We use this for drawing settings that aren't
+			// simple OpenGL options.
+
+			m_preprocessor = new SceneProcessor();
+
+			CustomAttributesPtr customAttributes = new CustomAttributes();
+			m_preprocessor->addChild( customAttributes );
+			customAttributes->inPlug()->setInput( m_preprocessor->inPlug() );
+			customAttributes->globalPlug()->setValue( true );
+			CompoundDataPlug *attr = customAttributes->attributesPlug();
 
-			// General :
+			StandardOptionsPtr standardOptions = new StandardOptions();
+			m_preprocessor->addChild( standardOptions );
+			standardOptions->inPlug()->setInput( customAttributes->outPlug() );
+			m_preprocessor->outPlug()->setInput( standardOptions->outPlug() );
+
+			// Included purposes
+
+			auto *includedPurposesPlug = standardOptions->optionsPlug()->getChild<NameValuePlug>( "includedPurposes" );
+			auto viewIncludedPurposesPlug = boost::static_pointer_cast<NameValuePlug>(
+				includedPurposesPlug->createCounterpart( "includedPurposes", Plug::In )
+			);
+			viewIncludedPurposesPlug->enabledPlug()->setValue( true );
+			drawingMode->addChild( viewIncludedPurposesPlug );
+			includedPurposesPlug->setInput( viewIncludedPurposesPlug );
+
+			// Visualiser settings.
 
 			ValuePlugPtr visualiser = new ValuePlug( "visualiser" );
 			drawingMode->addChild( visualiser );
@@ -431,7 +442,7 @@ class SceneView::DrawingMode : public Signals::Trackable
 			sceneGadget()->setOpenGLOptions( options.get() );
 		}
 
-		CustomAttributesPtr m_preprocessor;
+		SceneProcessorPtr m_preprocessor;
 
 		SceneView *m_view;
 

startup/gui/viewer.py

@@ -69,6 +69,8 @@ def __sceneView( plug ) :
 
 GafferUI.View.registerView( GafferScene.ScenePlug.staticTypeId(), __sceneView )
 
+Gaffer.Metadata.registerValue( GafferSceneUI.SceneView, "drawingMode.includedPurposes.value", "userDefault", IECore.StringVectorData( [ "default", "proxy" ] ) )
+
 # Add items to the viewer's right click menu
 
 def __viewContextMenu( viewer, view, menuDefinition ) :