[usdview] add --camera cmdline arg

pxr/usdImaging/lib/usdviewq/__init__.py

@@ -79,6 +79,15 @@ def RegisterOptions(self, parser):
                             dest='primPath', type=str,
                             help='A prim path to initially select and frame')
 
+        parser.add_argument('--camera', action='store', default="main_cam",
+                            type=str, help="Which camera to set the view to on "
+                            "open - may be given as either just the camera's "
+                            "prim name (ie, just the last element in the prim "
+                            "path), or as a full prim path.  Note that if only "
+                            "the prim name is used, and more than one camera "
+                            "exists with the name, which is used will be"
+                            "effectively random")
+
         parser.add_argument('--mask', action='store', nargs='+',
                             dest='populationMask', metavar='PRIMPATH',
                             help='Limit stage population to these prims, '
@@ -141,6 +150,37 @@ def ValidateOptions(self, arg_parse_result):
             print >> sys.stderr, "WARNING: complexity %.1f is out of range [1.0, 2.0], using %.1f instead" %  \
                                  (arg_parse_result.complexity, newComplexity)
             arg_parse_result.complexity = newComplexity
+
+        # convert the camera result to an sdf path, if possible, and verify
+        # that it is "just" a prim path
+        if arg_parse_result.camera:
+            from pxr import Sdf
+            camPath = Sdf.Path(arg_parse_result.camera)
+            if camPath.isEmpty:
+                print >> sys.stderr, "ERROR: invalid camera path - %r" % \
+                                     (arg_parse_result.camera,)
+                return False
+            if not camPath.IsPrimPath():
+                print >> sys.stderr, "ERROR: invalid camera path - must be a " \
+                                     "raw prim path, without variant " \
+                                     "selections, relational attributes, etc " \
+                                     "- got: %r" % \
+                                     (arg_parse_result.camera,)
+                return False
+
+            # check if it's a path, or just a name...
+            if camPath.name != arg_parse_result.camera:
+                # it's a "real" path, store the SdfPath version
+                if not camPath.IsAbsolutePath():
+                    # perhaps we should error here? For now just pre-pending
+                    # root, and printing warning...
+                    print >> sys.stderr, "WARNING: camera path %r was not " \
+                                         "absolute, prepending %r to make " \
+                                         "it absolute" % \
+                                         (str(camPath),
+                                          str(Sdf.Path.absoluteRootPath))
+                    camPath = camPath.MakeAbsolutePath(Sdf.Path.absoluteRootPath)
+                arg_parse_result.camera = camPath
         return True
 
     def __LaunchProcess(self, arg_parse_result):

pxr/usdImaging/lib/usdviewq/mainWindow.py

@@ -300,6 +300,12 @@ def __init__(self, parent, parserData):
         self._timeSamples = None
         self._stageView = None
         self._startingPrimCamera = None
+        if isinstance(parserData.camera, Sdf.Path):
+            self._startingPrimCameraName = None
+            self._startingPrimCameraPath = parserData.camera
+        else:
+            self._startingPrimCameraName = parserData.camera
+            self._startingPrimCameraPath = None
 
         self.setWindowTitle(parserData.usdFile)
         self._statusBar = QtGui.QStatusBar(self)
@@ -2688,14 +2694,35 @@ def _refreshCameraListAndMenu(self, preserveCurrCamera):
                 preserveCurrCamera = False
 
         if not preserveCurrCamera:
-            for camera in self._allSceneCameras:
-                # XXX This logic needs to be de-pixarified.  Perhaps
-                # a "primaryCamera" attribute on UsdGeomCamera?
-                if camera.GetName() == "main_cam":
-                    self._startingPrimCamera = currCamera = camera
-                    if self._stageView:
-                        self._stageView.setCameraPrim(camera)
-                    break
+            cameraWasSet = False
+            def setCamera(camera):
+                self._startingPrimCamera = currCamera = camera
+                if self._stageView:
+                    self._stageView.setCameraPrim(camera)
+                cameraWasSet = True
+
+            if self._startingPrimCameraPath:
+                prim = self._stage.GetPrimAtPath(self._startingPrimCameraPath)
+                if not prim.IsValid():
+                    msg = sys.stderr
+                    print >> msg, "WARNING: Camera path %r did not exist in " \
+                                  "stage" % (str(self._startingPrimCameraPath),)
+                    self._startingPrimCameraPath = None
+                elif not prim.IsA(UsdGeom.Camera):
+                    msg = sys.stderr
+                    print >> msg, "WARNING: Camera path %r was not a " \
+                                  "UsdGeom.Camera" % \
+                                  (str(self._startingPrimCameraPath),)
+                    self._startingPrimCameraPath = None
+                else:
+                    setCamera(prim)
+
+            if not cameraWasSet and self._startingPrimCameraName:
+                for camera in self._allSceneCameras:
+                    if camera.GetName() == self._startingPrimCameraName:
+                        setCamera(camera)
+                        break
+
         # Now that we have the current camera and all cameras, build the menu
         self._ui.menuCamera.clear()
         for camera in self._allSceneCameras: