Added SceneReaderPathPreview class.

This allows scene caches to be previewed in the browser and view apps. A node toolbar provides options for adding a camera to the scene and having it track a particular object.

Fixes #416 and fixes #636 by way of demonstrating how it can be done.

python/GafferSceneUI/SceneReaderPathPreview.py

@@ -0,0 +1,177 @@
+##########################################################################
+#  
+#  Copyright (c) 2014, Image Engine Design Inc. All rights reserved.
+#  
+#  Redistribution and use in source and binary forms, with or without
+#  modification, are permitted provided that the following conditions are
+#  met:
+#  
+#      * Redistributions of source code must retain the above
+#        copyright notice, this list of conditions and the following
+#        disclaimer.
+#  
+#      * Redistributions in binary form must reproduce the above
+#        copyright notice, this list of conditions and the following
+#        disclaimer in the documentation and/or other materials provided with
+#        the distribution.
+#  
+#      * Neither the name of John Haddon nor the names of
+#        any other contributors to this software may be used to endorse or
+#        promote products derived from this software without specific prior
+#        written permission.
+#  
+#  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
+#  IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+#  THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+#  PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+#  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+#  EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+#  PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+#  PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+#  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+#  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+#  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#  
+##########################################################################
+
+import IECore
+
+import Gaffer
+import GafferUI
+
+import GafferScene
+
+class SceneReaderPathPreview( GafferUI.PathPreviewWidget ) :
+
+	def __init__( self, path ) :
+
+		column = GafferUI.SplitContainer( GafferUI.SplitContainer.Orientation.Vertical )
+
+		GafferUI.PathPreviewWidget.__init__( self, column, path )
+
+		self.__script = Gaffer.ScriptNode( "scenePreview" )
+		self.__script["reader"] = GafferScene.SceneReader()
+
+		self.__script["camera"] = _Camera()
+		self.__script["camera"]["in"].setInput( self.__script["reader"]["out"] )
+
+		column.append( GafferUI.Viewer( self.__script ) )
+		column.append( GafferUI.Timeline( self.__script ) )
+
+		self.__script.selection().add( self.__script["camera"] )
+
+		self._updateFromPath()
+
+	def isValid( self ) :
+
+		if not isinstance( self.getPath(), Gaffer.FileSystemPath ) or not self.getPath().isLeaf() :
+			return False
+
+		return str( self.getPath() ).split( "." )[-1] in GafferScene.SceneReader.supportedExtensions()
+
+	def _updateFromPath( self ) :
+
+		if not self.isValid() :
+			self.__script["reader"]["fileName"].setValue( "" )
+			return
+
+		fileName = str( self.getPath() )
+		self.__script["reader"]["fileName"].setValue( fileName )
+
+		scene = IECore.SharedSceneInterfaces.get( fileName )
+		if hasattr( scene, "numBoundSamples" ) :
+			numSamples = scene.numBoundSamples()
+			if numSamples > 1 :
+				startFrame = int( scene.boundSampleTime( 0 ) * 24.0 )
+				endFrame = int( scene.boundSampleTime( numSamples - 1 ) * 24.0 )
+				self.__script["frameRange"]["start"].setValue( startFrame )
+				self.__script["frameRange"]["end"].setValue( endFrame )
+				GafferUI.Playback.acquire( self.__script.context() ).setFrameRange( startFrame, endFrame )
+
+GafferUI.PathPreviewWidget.registerType( "Scene", SceneReaderPathPreview )
+
+class _Camera( Gaffer.Node ) :
+
+	def __init__( self, name = "_Camera" ) :
+
+		Gaffer.Node.__init__( self, name )
+
+		self["in"] = GafferScene.ScenePlug()
+		self["addCamera"] = Gaffer.BoolPlug( defaultValue = False )
+		self["lookAt"] = Gaffer.StringPlug( defaultValue = "/" )
+		self["depth"] = Gaffer.FloatPlug( defaultValue = 20, minValue = 0 )
+		self["angle"] = Gaffer.FloatPlug()
+		self["elevation"] = Gaffer.FloatPlug( defaultValue = 10, minValue = -90, maxValue = 90 )
+
+		self["camera"] = GafferScene.Camera()
+		self["camera"]["name"].setValue( "previewCamera" )
+
+		self["parent"] = GafferScene.Parent()
+		self["parent"]["in"].setInput( self["in"] )
+		self["parent"]["parent"].setValue( "/" )
+		self["parent"]["child"].setInput( self["camera"]["out"] )
+
+		self["cameraFilter"] = GafferScene.PathFilter()
+		self["cameraFilter"]["paths"].setValue( IECore.StringVectorData( [ "/previewCamera" ] ) )
+
+		self["parentConstraint"] = GafferScene.ParentConstraint()
+		self["parentConstraint"]["in"].setInput( self["parent"]["out"] )
+		self["parentConstraint"]["target"].setInput( self["lookAt"] )
+		self["parentConstraint"]["targetMode"].setValue( self["parentConstraint"].TargetMode.BoundCenter )
+		self["parentConstraint"]["filter"].setInput( self["cameraFilter"]["match"] )
+
+		self["cameraRotate"] = GafferScene.Transform()
+		self["cameraRotate"]["in"].setInput( self["parentConstraint"]["out"] )
+		self["cameraRotate"]["transform"]["rotate"]["y"].setInput( self["angle"] )
+		self["cameraRotate"]["space"].setValue( self["cameraRotate"].Space.Object )
+		self["cameraRotate"]["filter"].setInput( self["cameraFilter"]["match"] )
+
+		self["elevationExpression"] = Gaffer.Expression()
+		self["elevationExpression"]["engine"].setValue( "python" )
+		self["elevationExpression"]["expression"].setValue( 'parent["cameraRotate"]["transform"]["rotate"]["x"] = -parent["elevation"]' )
+
+		self["cameraTranslate"] = GafferScene.Transform()
+		self["cameraTranslate"]["in"].setInput( self["cameraRotate"]["out"] )
+		self["cameraTranslate"]["transform"]["translate"]["z"].setInput( self["depth"] )
+		self["cameraTranslate"]["space"].setValue( self["cameraRotate"].Space.Object )
+		self["cameraTranslate"]["filter"].setInput( self["cameraFilter"]["match"] )
+
+		self["options"] = GafferScene.StandardOptions()
+		self["options"]["options"]["renderCamera"]["enabled"].setValue( True )
+		self["options"]["options"]["renderCamera"]["value"].setValue( "/previewCamera" )
+		self["options"]["in"].setInput( self["cameraTranslate"]["out"] )
+
+		self["switch"] = GafferScene.SceneSwitch()
+		self["switch"]["in"].setInput( self["in"] )
+		self["switch"]["in1"].setInput( self["options"]["out"] )
+		self["switch"]["index"].setInput( self["addCamera"] )
+
+		self["out"] = GafferScene.ScenePlug( direction = Gaffer.Plug.Direction.Out )
+		self["out"].setInput( self["switch"]["out"] )
+
+IECore.registerRunTimeTyped( _Camera )
+
+GafferUI.NodeToolbar.registerCreator( _Camera.staticTypeId(), GafferUI.StandardNodeToolbar )
+GafferUI.PlugValueWidget.registerCreator( _Camera.staticTypeId(), "in", None )
+GafferUI.PlugValueWidget.registerCreator( _Camera.staticTypeId(), "out", None )
+GafferUI.PlugValueWidget.registerCreator( _Camera.staticTypeId(), "user", None )
+
+GafferUI.PlugValueWidget.registerCreator(
+	_Camera.staticTypeId(),
+	"lookAt",
+	lambda plug : GafferUI.PathPlugValueWidget(
+		plug,
+		path = GafferScene.ScenePath( plug.node()["in"], plug.node().scriptNode().context(), "/" ),
+	),
+)
+
+def __fixedWidthNumericPlugValueWidget( plug ) :
+
+	result = GafferUI.NumericPlugValueWidget( plug )
+	result.numericWidget().setFixedCharacterWidth( 5 )
+
+	return result
+
+GafferUI.PlugValueWidget.registerCreator( _Camera.staticTypeId(), "depth", __fixedWidthNumericPlugValueWidget )
+GafferUI.PlugValueWidget.registerCreator( _Camera.staticTypeId(), "angle", __fixedWidthNumericPlugValueWidget )
+GafferUI.PlugValueWidget.registerCreator( _Camera.staticTypeId(), "elevation", __fixedWidthNumericPlugValueWidget )

python/GafferSceneUI/__init__.py

@@ -72,3 +72,4 @@
 import ShaderAssignmentUI
 import ParentConstraintUI
 import ParentUI
+from SceneReaderPathPreview import SceneReaderPathPreview