Pico Link / Streaming Assistant woes ;)

To be able to do PCVR you will need some piece of software that links your headset (P3 or P4 series) with SteamVR. So far, to my knowledge the options are
- Streaming Assistant (for Pico Series 3)
- Pico Link (for Pico Neo 3 Link)
- Streaming Assistant (for Pico 4)
- ALVR (Air Light VR) and it's Pico client (ALXR)
- Virtual Desktop
 
Pico Link and Streaming Assistant (SA) are Pico 'official' options, but they are quite "picky" to configure and setup and sometimes they don't want to work properly.
There is no much different between the two other than Pico Link supports DP connection (PN3L), you can use any of those on your headset (assuming you have the appropiate headset application (apk) installed.

Below is a list of some of the common problems I encounter with both software which may help people to diagnose/fix issues before asking for help. (I may use the SA term but same applies to both Pico Link and Streaming Assistant)




1. **Hardware Compatibility check failure**:
	SA checks that your machine has the minimal hardware (CPU/Memory/GPU) to be able to run. If one of the checks fails it will not let you continue.
	To do this it uses a json object stored in a `compare.json` file in its main directory
	`c:\Program Files\Streaming Assistant\compare.json`
	`c:\Program Files (x86)\Pico Link\compare.json`
	If your hardware is not listed there you will get an error and depending on the type it may not let you continue.
	To fix it:
	Edit the `assistant.ini` file in the SA main directory and make sure it looks like:
	`
	[General]
	 language=EN
	 firststart=1
	 displaylevel=1
	 mode=-1
	`

	Then edit the `compare.json` file and replace one of the existing entries with yours (like `RTX 3080` for `RTX 4090`)

	Restart SA and it should.
	Another 'dirty' option is to just change the `compare.json` file attributes to READ-ONLY without any edits.
	It should complaint about not be able to do any hardware checks, but will let you move to the next config step.


2. **Software environment check failure**.
	Here SA is checking (in theory) if you have the proper software installed (like SteamVR or the Pico SteamVR addon)
	Sometimes this fails (even if you have all as it should), or it works (if you have something missing)
	Most common error is SA not be able to find SteamVR. To do so SA checks for a couple of things on your system.

2.1 **SteamVR** 
	First it checks if SteamVR is listed as an Installed Program checking the Uninstall registry keys.
	Run the following from a command prompt:
	`reg query "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\Steam App 250820"`
	and check that the output looks like:
	`
	C:\Windows\system32>reg query "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\Steam App 250820"

	HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\Steam App 250820
		DisplayIcon    REG_SZ    C:\Program Files (x86)\Steam\steam\games\b41e5f61d7c00b9a53abf310325131d7867f4770.ico
		DisplayName    REG_SZ    SteamVR
		HelpLink    REG_SZ    https://help.steampowered.com/
		InstallLocation    REG_SZ    C:\Program Files (x86)\Steam\steamapps\common\SteamVR
		Publisher    REG_SZ    Valve
		UninstallString    REG_SZ    "C:\Program Files (x86)\Steam\steam.exe" steam://uninstall/250820
		URLInfoAbout    REG_SZ    https://steamcommunity.com/steamvr
		NoRepair    REG_DWORD    0x1
		NoModify    REG_DWORD    0x1

	C:\Windows\system32>
	`

	Next it will check the shell associations for specific binaries (SteamVR binaries).
	Run the following from the same command prompt:
	
		`reg query "HKCU\Software\Classes\vrmonitor\Shell\Open\Command"`

	Output should look like:
		`
		C:\Windows\system32>reg query "HKCU\Software\Classes\vrmonitor\Shell\Open\Command"

		HKEY_CURRENT_USER\Software\Classes\vrmonitor\Shell\Open\Command
			(Default)    REG_SZ    "C:\Program Files (x86)\Steam\steamapps\common\SteamVR\bin\win64\vrmonitor.exe" "%1"

		C:\Windows\system32>
		`

	Take notice of the command output. It should list your steamVR installation directory.
	If anty those keys are empty, SA will fail to detect your SteamVR (Even if SteamVR is working properly)
	You could either reinstall SteamVR (and check if the proper values are there) or fix it manually editing the entries with `regedit`



2.2 **Pico Addon failure**
	I never saw SA complaining here, even if the driver/addon was not properly registered but this is critical and maye is the most common issue.
	This is the driver (`external_driver`) that enables SteamVR to 'communicate' with your headset.	 
	SteamVR uses an `openvr.vrpath` file in your Windows profile directory to control which drivers/addons to load at startup.
	Run the following command from a command prompt:
		`type c:\Users\%USERNAME%\AppData\Local\openvr\openvrpaths.vrpath`
	For SA it should look something like:
		`
		C:\Windows\system32>type c:\Users\%USERNAME%\AppData\Local\openvr\openvrpaths.vrpath
		{
				"config" :
				[ 
						"c:\\program files (x86)\\steam\\config"
				],
				"external_drivers" :
				[                
						"C:/Program Files/Streaming Assistant/driver"
				],
				"jsonid" : "vrpathreg",
				"log" :
				[
						"C:\\Program Files (x86)\\Steam\\logs"         
				],
				"runtime" :
				[
						"C:\\Program Files (x86)\\Steam\\steamapps\\common\\SteamVR"
				],
				"version" : 1
		}
		C:\Windows\system32>
		`

	The `external_drivers` section is the key to get the Pico addon working.
	The Pico driver listed there should match whatever Pico app (Pico Link or SA) you use, otherwise it will not work.
	Both Pico Link and Streaming Assistant (SA) will add its own directory there, so if you have installed and run both,
	you may end with more than one entries there like:

		`
		C:\Windows\system32>type c:\Users\%USERNAME%\AppData\Local\openvr\openvrpaths.vrpath
		{
				"config" :
				[ 
						"c:\\program files (x86)\\steam\\config"
				],
				"external_drivers" :
				[
						"C:/Program Files (x86)/Pico Link/driver",
						"C:/Program Files/Streaming Assistant/driver"
				],
				"jsonid" : "vrpathreg",
				"log" :
				[
						"C:\\Program Files (x86)\\Steam\\logs"         
				],
				"runtime" :
				[
						"C:\\Program Files (x86)\\Steam\\steamapps\\common\\SteamVR"
				],
				"version" : 1
		}
		C:\Windows\system32>
		`
	Which is "problematic" as the driver/addon has the same name.

	If there is no entries in the "external_driver", it looks like:
		`
		C:\Windows\system32>type c:\Users\%USERNAME%\AppData\Local\openvr\openvrpaths.vrpath
		{
				"config" :
				[ 
						"c:\\program files (x86)\\steam\\config"
				],
				"external_drivers" : null,
				"jsonid" : "vrpathreg",
				"log" :
				[
						"C:\\Program Files (x86)\\Steam\\logs"         
				],
				"runtime" :
				[
						"C:\\Program Files (x86)\\Steam\\steamapps\\common\\SteamVR"
				],
				"version" : 1
		}
		C:\Windows\system32>
		`
	It means the Pico driver/addon is not registered, so it will not work.
	Again, either reinstall SA and run it (and check the entry is there) or manually add it to the file.



3. **Version mismatched**
	If you get pass the SA checks, it should allow you to connect, either by Wifi or USB to your headset.
	As I said before, you need to 'proper' apk been installed, Pico Link will need Pico Link app, SA will need SA otherwise you will get a message telling you that you need to upgrade (either the apk or the Windows app).
	Only way around this is to make sure your versions are in `sync`. 


4. **SteamVR not detecting the headset**
4.1 **Disabled Pico add-on**
	Another common problem is that, even if PicoLink/SA is connected to the headset, and you can see the black/3 dot screen on the headset, SteamVR fails to find the headset and it never display the Steam mountains environment.

	There could be several reason, but the most common one is that the addon (the Pico driver) is either disabled, or not registered properly.
	First, go to your SteamVR menu (click on the 3 horizontal bars icon on the left of the Stream Window).
	Choose `Settings` and then click on `MANAGAGE ADD-ONS`. (If you can see `MANAGE ADD-ONS` check that `Advanced Settings` on the bottom is set to `Show`
	In the `Manage SteamVR Add-Ons` you should see at least one entry listed as `pico` and it should be marked as `On` for the driver to work.

	SteamVR may disable the addon if it encountered an error so always check that first.

4.2 **Windows Network setting (Public/Private)**
	If the addon is enabled, but SteamVR is still failing to find the headset, check our Windows network settings.
	Try swithing your network mode from Private to Public or the other way around and restart SteamVR.

	If it still doesn't work it could be a driver (GPU) problem, try updating your GPU driver to the latest one availeble.
	Steam/Pico logs may also give you some clues.
	Check either `c:\Program Files\Streaming Assistant\Logs\` or `c:\Program Files (x86)\Steam\logs\`

5. **SteamVR previous installed headset**
	In some case, having a previous configured VR headset in SteamVR may cause troubles.
	You could always reinstall SteamVR, but a simpler method that works for me is to delete or rename the SteamVR config file at
	`c:\Program Files (x86)\Steam\config\steamvr.vrsettings`

Rename it, restart SteamVR and it should start `fresh`

6. **Controller compatibility**. 
	If you got here, you should have SA working already. There are a couple of files which controlls how SA works.
	`c:\Program Files\Streaming Assistant\assistant.ini`
	`c:\Program Files\Streaming Assistant\driver\bin\win64\RVRPlugin.ini`
	There are some options available in the SA setting but some are hidden.
	Changing `controllers=1` in the `RVRPlugin.ini` file (needs bouncing both SA and SteamVR) will give you the Quest controllers which I believe are the most compatible ones in terms of SteamVR bindings.



7. **Couple of final recomendations**: 
	1. Stick to defaul install locations (drive/directory) until you know everything works.
	2. Try 'current' versions, don't jump into trying betas or other product flauvours (like SA on Pico 3, or Pico Link on P4) until you know everything works.
	3. Disable firewalls while troubleshooting network problems. Everything steamVR uses pipes and sockets which are easly broken if there are no proper firewall exceptions.
	4. Try running as `Administrator` as your user may not have all the needed privileges for all the gears to work properly