Python <-> Rust bridge fixes (#42)

* Python SDK: fix log_points without colors

* Python SDK: Fix: copy numpy views -> log_points_rs

* Python example: increase to 40 samples again

crates/re_sdk_python/example.py

@@ -12,7 +12,7 @@
 
 def log_dummy_data(args):
     """Log a few frames of generated dummy data to show how the Rerun SDK is used."""
-    NUM_FRAMES = 20
+    NUM_FRAMES = 40
 
     for sample in generate_dummy_data(num_frames=NUM_FRAMES):
         # This will assign logged objects a "time source" called `frame_nr`.
@@ -22,10 +22,7 @@ def log_dummy_data(args):
         # The depth image is in millimeters, so we set meter=1000
         rerun.log_depth_image("depth", sample.depth_image_mm, meter=1000)
 
-        # TODO(nikolausWest): Make setting the color here optional
-        rgba = [200, 0, 100, 200]
-        colors = np.array([rgba])
-        rerun.log_points("depth3D", sample.point_cloud.copy(), colors)
+        rerun.log_points("depth3D", sample.point_cloud)
 
         rerun.log_image("rgb", sample.rgb_image)
 

crates/re_sdk_python/python/rerun_sdk/__init__.py

@@ -106,7 +106,10 @@ def log_points(obj_path, positions, colors=None, space=None):
     If no `space` is given, the space name "2D" or "3D" will be used,
     depending on the dimensionality of the data.
     """
-    if colors is not None:
+    if colors is None:
+        # An empty array represents no colors.
+        colors = np.array((), dtype=np.uint8)
+    else:
         # Rust expects colors in 0-255 uint8
         if colors.dtype in ['float32', 'float64']:
             if np.amax(colors) < 1.1:
@@ -119,6 +122,10 @@ def log_points(obj_path, positions, colors=None, space=None):
 
     positions.astype('float32')
 
+    # Workaround to handle that `rerun_rs` can't handle numpy views correctly.
+    # TODO(nikolausWest): Remove this extra copy once underlying issue in Rust SDK is fixed.
+    positions = positions if positions.base is None else positions.copy()
+
     rerun_rs.log_points_rs(obj_path, positions, colors, space)
 
 

crates/re_sdk_python/src/python_bridge.rs

@@ -192,7 +192,7 @@ fn log_bbox(
 fn log_points_rs(
     obj_path: &str,
     positions: numpy::PyReadonlyArray2<'_, f64>,
-    colors: numpy::PyReadonlyArray2<'_, u8>,
+    colors: numpy::PyReadonlyArrayDyn<'_, u8>,
     space: Option<String>,
 ) -> PyResult<()> {
     if positions.is_empty() {