Spent some time figuring this out and just wanted to share:

The use-case

I have a desktop PC running Windows and some software for 3D modelling. For when I am at my desk, I have a 3dConnexion Space Explorer. I often work remotely, connecting to this PC via RDP using Remmina. Works great, only 3D navigation is annoyingly slow… Therefore, I'd like to have an additional SpaceMouse which I can use with my mobile laptop running Fedora Linux.

The problem now is to pass the USB device through the RDP connection such that it appears at my desktop as input device.

The remote connection is set up using the RemoteDesktop feature of Windows and Remmina on Fedora Linux. There are plenty tutorials out there covering this setup. The following deals only with the additional settings needed for the USB passthrough.

Setup of the host PC (running windows)

The instructions were found provides drivers for all 3dConnexion 6dof devices. This makes an installation of the drivers from 3dConnexion on the Linux machine obsolete. (You still need them on the windows machine)

At first, install spnavcfg and spnavd, e.g. using sudo dnf install spnavcfg spnavd.

Check whether the daemon is running: sudo systemctl status spacenavd.service

If you need to start the daemon, just run

• sudo systemctl enable spacenavd.service
• sudo systemctl start spacenavd.service

Through the GUI spnavcfg, you can now tweak all settings of the space mouse (much nicer than with the proprietary driver, imho).

The LED at the space mouse should be illuminated and you should be able to navigate with it, e.g. in FreeCad or Blender. Unlike on Windows, it's not possible to use it as a mouse wheel for scrolling…

In order to set up the USB pass-through, the following steps are needed:

1. query idVendor and idProduct of the SpaceMouse

Use lsusb to find the vendor and product id of the mouse. The correct line could look like so:

user@pc:~$ lsusb ... Bus 003 Device 011: ID 046d:c627 Logitech, Inc. 3Dconnexion Space Explorer 3D Mouse ... 

The part ID idVendor:idProduct (here: ID 046d:c627) is important, take note of your respective idVendor and idProduct.

2. Set up a new user group to allow rw access to the device

In order to access the device with remmina, the user needs rw access to the raw device. This is accomplished through a new user group, I called it 3dmouse. Create the new group and add yourself:

sudo groupadd 3dmouse sudo usermod -aG 3dmouse your_username 

3. udev rule for correct group association

Now you need to set up a udev rule which adds the device to the correct user group upon mounting. Create it as sudo under /etc/udev/rules.d/50-3dmouse.rules with this content:

SUBSYSTEM=="usb", ATTRS{idVendor}=="046d", ATTRS{idProduct}=="c627", GROUP="3dmouse" 

Make sure to replace the numbers for idVendor and idProduct with the correct values for your specific model!

Now restart (or logout and back in) for the udev rule to take effect.

4. Check if group was set correctly

Run lsusb again to get the current bus and device numbers, e.g. Bus 003 Device 011. This gives the path to the device as /dev/bus/usb/003/011. Bus and device numbers change with every plug or boot, so make sure to run lsusb again after the reboot. Now you can run ls -al /dev/bus/usb/003/011. This should show the file's permissions set to rw-rw----

5. Set up remmina

In remmina, right click on your connection and go to Connection profile -> Redirection of USB devices. Here you can enter the device's idVendor and idProduct in this pattern: id:idVendor:idProduct (example with my IDs: id:046d:c627).

Save and establish the connection. You should now be able to control your software with the CAD mouse on the remote machine.

I'd be happy to hear if there are any hints on how to improve this! If somebody has experience with this workflow in combination with wireless devices from 3dConnexion, I'd also be happy to hear about that (thinking about getting one of the wireless mice…)