Meshcat-viewer: Scale of .obj meshes gets reset when transformation gets applied

[jviereck]

I've compiled the latest version of pinocchio from source and the latest meshcat-python package version. The parts of my robot are made of .obj meshes that are scaled to size. When I create a MeshcatVisualizer and load the URDF file, the .obj meshes are displayed, however, the scale seems to be ignored.

Spending some time debugging this, it looks like setting the transform

            # Update viewer configuration.
            self.viewer[visual_name].set_transform(T)

in MeshcatVisualizer::updatePlacements is causing the scaling property to be reset. When I apply the scaling once more like this:

            # Update viewer configuration.
            self.viewer[visual_name].set_transform(T)

            if visual_name in self.scales:
                self.viewer[visual_name].set_property("scale", self.scales[visual_name])

then the scale shows up properly in Meshcat. Here, self.scales is a new dict that stores the scaling values when the objects are created in MeshcatVisualizer::loadViewerGeometryObject.

Does this ring a bell for anyone?