make a Path class and test animation of properties

Author: rdeits

src/meshcat/animation.py

@@ -76,7 +76,7 @@ def __init__(self, clips=None, default_framerate=30):
 
     def lower(self):
         return [{
-            u"path": unicode("/" + "/".join(path)),
+            u"path": path.lower(),
             u"clip": clip.lower()
         } for (path, clip) in self.clips.items()]
 
@@ -111,8 +111,12 @@ def set_transform(self, matrix):
         clip.set_property(self.current_frame, "position", "vector3", js_position(matrix))
         clip.set_property(self.current_frame, "quaternion", "quaternion", js_quaternion(matrix))
 
+    def set_property(self, prop, jstype, value):
+        clip = self.get_clip()
+        clip.set_property(self.current_frame, prop, jstype, value)
+
     def __getitem__(self, path):
-        return AnimationFrameVisualizer(self.animation, self.path + tuple(path.split("/"), self.current_frame))
+        return AnimationFrameVisualizer(self.animation, self.path.append(path), self.current_frame)
 
     def __enter__(self):
         return self

src/meshcat/commands.py

@@ -26,7 +26,7 @@ def lower(self):
         return {
             u"type": u"set_object",
             u"object": self.object.lower(),
-            u"path": unicode("/" + "/".join(self.path))
+            u"path": self.path.lower()
         }
 
 
@@ -39,7 +39,7 @@ def __init__(self, matrix, path=[]):
     def lower(self):
         return {
             u"type": u"set_transform",
-            u"path": unicode("/" + "/".join(self.path)),
+            u"path": self.path.lower(),
             u"matrix": list(self.matrix.T.flatten())
         }
 
@@ -52,7 +52,7 @@ def __init__(self, path):
     def lower(self):
         return {
             u"type": u"delete",
-            u"path": unicode("/" + "/".join(self.path))
+            u"path": self.path.lower()
         }
 
 

src/meshcat/path.py

@@ -0,0 +1,30 @@
+from __future__ import absolute_import, division, print_function
+
+import sys
+if sys.version_info >= (3, 0):
+    unicode = str
+
+
+class Path(object):
+    __slots__ = ["entries"]
+
+    def __init__(self, entries=tuple()):
+        self.entries = entries
+
+    def append(self, other):
+        new_path = self.entries
+        for element in other.split('/'):
+            if len(element) == 0:
+                new_path = tuple()
+            else:
+                new_path = new_path + (element,)
+        return Path(new_path)
+
+    def lower(self):
+        return unicode("/" + "/".join(self.entries))
+
+    def __hash__(self):
+        return hash(self.entries)
+
+    def __eq__(self, other):
+        return self.entries == other.entries

src/meshcat/tests/test_drawing.py

@@ -101,7 +101,6 @@ def tearDown(self):
 
 class TestAnimation(VisualizerTest):
     def runTest(self):
-        self.vis.delete()
         v = self.vis["shapes"]
         v.set_transform(tf.translation_matrix([1., 0, 0]))
         v["cube"].set_object(g.Box([0.1, 0.2, 0.3]))
@@ -112,3 +111,21 @@ def runTest(self):
         with animation.at_frame(v, 30) as frame_vis:
             frame_vis.set_transform(tf.translation_matrix([2, 0, 0]).dot(tf.rotation_matrix(np.pi/2, [0, 0, 1])))
         v.set_animation(animation)
+
+
+class TestCameraAnimation(VisualizerTest):
+    def runTest(self):
+        v = self.vis["shapes"]
+        v.set_transform(tf.translation_matrix([1., 0, 0]))
+        v["cube"].set_object(g.Box([0.1, 0.2, 0.3]))
+
+        animation = meshcat.animation.Animation()
+        with animation.at_frame(v, 0) as frame_vis:
+            frame_vis.set_transform(tf.translation_matrix([0, 0, 0]))
+        with animation.at_frame(v, 30) as frame_vis:
+            frame_vis.set_transform(tf.translation_matrix([2, 0, 0]).dot(tf.rotation_matrix(np.pi/2, [0, 0, 1])))
+        with animation.at_frame(v, 0) as frame_vis:
+            frame_vis["/Cameras/default/rotated/<object>"].set_property("zoom", "number", 1)
+        with animation.at_frame(v, 30) as frame_vis:
+            frame_vis["/Cameras/default/rotated/<object>"].set_property("zoom", "number", 0.5)
+        v.set_animation(animation)

src/meshcat/visualizer.py

@@ -9,6 +9,7 @@
 import zmq
 import re
 
+from .path import Path
 from .commands import SetObject, SetTransform, Delete, SetAnimation
 from .geometry import MeshPhongMaterial
 
@@ -98,7 +99,7 @@ def __init__(self, zmq_url=None, window=None):
             self.window = ViewerWindow(zmq_url=zmq_url, start_server=(zmq_url is None))
         else:
             self.window = window
-        self.path = ("meshcat",)
+        self.path = Path(("meshcat",))
 
     @staticmethod
     def view_into(window, path):
@@ -128,7 +129,7 @@ def jupyter_cell(self):
 """.format(url=self.url()))
 
     def __getitem__(self, path):
-        return Visualizer.view_into(self.window, self.path + tuple(path.split("/")))
+        return Visualizer.view_into(self.window, self.path.append(path))
 
     def set_object(self, geometry, material=None):
         return self.window.send(SetObject(geometry, material, self.path))