Netplay

This page is still under construction. It's constantly being edited and reorganized to be more clear, accurate and easier to read during this alpha testing. These are our first drafts.

On this page you'll learn everything about Netplay in EmuVR: what can you do, what you need to do, what works, what does not work, and how to troubleshoot any issues.

Quick Steps

After reading this page, this will be burned into your mind:

1. Not all consoles and games support netplay
2. You need to have the same exact ROM as your friend
3. Hold Menu for half a second to show the Netplay Menu, then click Host
4. Click to Copy your code, then send it to your friend
5. Your friend clicks Paste, then clicks Connect
6. Play video games together!

But this TL;DR is the equivalent of "draw two circles, and now draw the rest of the damn owl". Keep reading this page to learn what you actually need to know to play!

The Basics

You're able to invite friends to your own customized room, where you'll see each other and play or watch games together.

Everyone will see your room as you do, with all custom textures, posters, walls, bed, and even game labels.

Anyone in the room can spawn objects or games, move them around, insert games into consoles, change cables; everything you already do in single player mode.

You can start or stop hosting at will, without the need to restart EmuVR, to reload any room, or to even restart any game you're already playing.

Your friends can join you mid-game, and all your running games will be synced to them (if they have the same games).

Even while friends are visiting you, you can still save and load your rooms as a host, change the season, time of day.

You and your friends can play together in desktop and VR mode.

* There is no integrated voice chat currently. You'll need to use a third party solution like Discord, Oculus Parties Voice Chat or Steam Voice Chat to communicate.

Playing games

1. Not every game or console supports netplay.
2. Everyone must have the same game to be able to play it.

Basically, anyone in the room can "grab the controller" and control any game as player 1 or player 2 or how many players that game support, like Arcade games with four players such as Teenage Mutant Ninja Turtles, or multitap games like Super Bomberman 5. Anyone can "pass the controller" and swap who's controlling who on the fly.

Some example scenarios:

• Play a 2-player game with your friend, versus or co-op.
• Play a single player game while your friends watch. You can pass the controller on the fly and anyone can continue the game while you watch.
• Each player plays a single player on each TV side by side. Different games, or how about a speedrun race of the same game?
• Several pair of players play different multiplayer games each, at same time on different TVs in the same room. Anyone can switch controllers, change pairs, and control any other game at any time.

The limit is your hardware power and internet speed and quality. The one player with worse internet or hardware might bring others' experiences down.

Again, not every game or console supports netplay, and everyone must have the same exact game to play or even watch it.

Requirements

Netplay has some specific requirements to work.

1. Everyone needs the same EmuVR version.
2. Everyone needs the same Retroarch version (Already taken care of for you)
3. Everyone needs the same exact Cores, same versions. (Already taken care of for you)
4. Everyone needs the same Retroarch settings. (Already taken care of for you, to some extent)
5. Everyone needs the same exact ROM files. (We don't provide ROMs, don't ask and don't share)
6. The host's computer needs to be directly reachable on the internet, through port forwarding or UPnP.

You don't need to have all the same games. If you're missing some specific game, others that do have it will still be able to play it, and only you will see a blank TV for that game.

Matching Games

To be able to play or even watch a game, you and your friend will need to have the same exact ROM file for that game.

File names or paths do not matter. What only matters for matching games are the actual file contents, which are detected when scanning them (calculating their CRC hashes).

Again, to be clear: it doesn't matter if they're zipped or not, if they have totally different file names or are in differently named folders.

Inventory

Joining a host is analogous to visiting a friend's house: you'll see their room with all their games, not yours.

That's what you see in your own inventory while visiting a host: their own games, with their own labels, the same they see while playing offline by themselves.

If you don't have some of the host's games, they'll still show up in your inventory menu, they still exist in the room as carts / CDs with (the host's) labels, and are interactable as usual. They just won't play on TVs for you, but the host or any other visiting friend that does have that matching game will be able to see and play it on TVs.

If anyone currently in the room doesn't have a game, that cartridge / CD will display a little "broken connection" icon for everyone.

• If you're the one without the matching game, you'll see a orange icon. You can interact with the physical media, but it won't play on TVs.
• If you do have the matching game and someone else does not, you'll see a green icon, even if you're the host. This will let you know that someone in the room won't be able to play that game, but you and others with the green icon will.
• If there's no icon at all on the game, it means everyone in the room has it.

TL;DR: See Orange WiFi icon on a game, you don't have it on your machine and can't play or watch it.
See Green WiFi icon on a game, someone else in the room doesn't have it but you do. Only Green-icon friends can play or watch that game with you.

Netplay Menu

To show the Netplay Menu, you can navigate to it from the Settings Menu, or simply use the Netplay Menu Shortcut: hold Menu for half a second.

Point to anything there and you'll see a tooltip with explanations.

There you'll be able to set your nickname, your player color, host your room, join another room, check other players' status and, if you're the host, kick them out.

If you don't write in any name, you'll be named "Player 1", "Player 2", etc.

If you don't pick any color (or click Reset Color), as a host you'll be the default blue color, and as a client you'll be assigned a random color each time you join a room.

Click Host to start accepting friends. Click Copy to grab your Address Code, and send them to your friends.

Your Address Code is generated from your external IP. If your IP hasn't changed, you'll always see the same code. Actual IP addresses can be used to connect as well.

To join a host, click Paste or write the code or IP you've received, write the password if needed, then click Connect. Attention: by clicking Connect, you'll reload your latest saved (or default) room state, even if your connection attempt fails.

The Players List to the right will show all players in the room, their names, color, ping, and a button to kick them if you're the host.

Notice you can still edit the password field even after you've started

Pay attention the Log panel to see helpful messages and solutions regarding issues you might be having related to Netplay.

* Currently there's no ingame keyboard, so you'll need to use your real keyboard to write in them for now, or the virtual keyboards available in Oculus Dash, SteamVR or Virtual Desktop.

TL;DR Quick Steps

1. Hold Netplay Menu Shortcut
2. Click 'Host
3. Click Copy to grab your room Code
4. Send the Code to your friends
5. As a client, Paste the code, then click Connect

If you're having trouble and no one can connect to you, check the Port Forwarding section.

Controlling Games

Hosts and clients can Focus and Unfocus games as usual.

The first person to focus into a game will get the Player 1 controller, the next one will be Player 2, and so on. When you unfocus the game, you'll free that player slot, and anyone focusing on that TV will use the first available controller.

Examples:

• Two players focused to a game, P1 unfocus it, freeing P1 slot
• A third person could focus into it and become the new P1, while P2 continues to be P2, and the old P1 is now a spectator
• Alternatively, P2 can quickly unfocus and focus again on the game, becoming P1
• Following the case above, if the previous P1 tries to focus input back again, the first available slot for them will be a P2 controller, so they've effectively swapped controllers

When focusing or unfocusing into a game, the screen will show a message letting you know, by their set nickname, who is controlling that game, and with which controller.

Important: Just by joining a room, you're always connected through Retroarch's netplay on all games currently running, even if no one is controlling them.

Port Forwarding

If you're hosting, you'll need to open some specific ports or your friends won't be able to connect to you.

For most modern routers, you won't need to do anything, as the ports will be automatically opened for you through UPnP / NAT Punch-through. You might still need to enable UPnP on your router, so please refer to your router manual.

If that doesn't work in your case, you'll need to manually forward the following ports:

• Port 4700 UDP (For EmuVR)
• Port 4700 to 4730 TCP (For multiple Retroarch instances)

The above means port 4700, 4701, 4702 ... 4729, 4730, TCP.

That's one port for each console you're planning to play simultaneously.

Notice that port 4700 needs to be forwarded for both UDP and TCP. (TCP 4700 is reserved for textures and cores syncing)

If you never plan to play more than 10 games simultaneously, you can open up to port 4710. If you have a super machine and plan to play 99 games simultaneously with friends that have super machines too, you should open up to port 4799.

To make it clear, each time you start a console, it will take up one slot, and after shutting it down, it will free that slot. If you play 50 games but one at a time, you'll use only one port, 4701.

Since each router brand and model has a very different kind of interface, it's impossible to write a universal guide. Unfortunately this might not be easy for the inexperienced user. Here are some guides on port forwarding for several interfaces: [1], [2], [3], [4], [5]. (Avoid downloading any software claiming to help you with it)

If your ISP somehow doesn't allow you to forward ports on your router, you won't be able to host a room in EmuVR unfortunately, but you can still connect to other players.

You'll need to allow EmuVR.exe and Retroarch.exe on your Firewall rules as well. Here's a guide for adding Firewall exceptions on Windows, and here's another one. If you're using a third party antivirus, it might have its own firewall settings.

Supported Systems and Games

Not every game or console supports netplay.

EmuVR relied on Retroarch's own netplay for the games. Not every core supports netplay.

The rule of thumb is: If it's newer than PS1 or N64, or a 3D game, it very likely doesn't support netplay.
(Refer to Retroarch's own Netplay FAQ)

Link-cable or internet connected games such as GB, GBC, GBA, PSP, NDS aren't possible either.
However you can still play them as any other single player game while others watch, and pass the controller to them.

While PS1 is not supposed to work, it does work well on our tests with Beetle PSX.

N64 might work depending on the game, on your hardware and your internet, but it's also prone to desync and even disconnections in some cases. More than 2 players can be even more unstable depending on the same mentioned factors. Mupen64Plus only, ParaLLEl N64 doesn't work at all.

Computer cores, like DOS, Amiga, Commodore, usually do not support netplay.

Arcade games are well supported with cores FB-Neo and FB Alpha, but not with MAME.

Light Gun games are supported, including two-player games. Some few light gun games might be prone to desync. (More reports are wanted)

Currently, NES Zapper games do not work with netplay. Common NES games are pretty well supported.

Unfortunately, videos or music aren't supported currently, since the FFmpeg core doesn't support netplay.

We haven't tested every single core with netplay yet, so you can help us learn what works best, what desyncs a lot, and what uses too much CPU and RAM in netplay mode.

Core Syncing

Retroarch's netplay requires the same exact core version to work. EmuVR deals with it for you automatically. This section is more about what you don't need to worry about.

When you're visiting a host and try to start a game, the host will automatically send the needed core to clients, if they don't have the exact same core and version. They're cached to prevent being sent every time you join. They will not replace your own installed cores.

Without this, all players would have to organize and to be sure they have the same exact cores before joining a host. And since many cores are updated weekly or even daily, you'd have to redo all this and replace your own cores each time they're joining a new host.

Core syncing allows players to connect with anyone with just a code, no need to plan and exchange files before joining.

Netplay also requires some specific Retroarch settings and core options to be exactly same same. EmuVR will also sync this automatically for you, and when joining a host you'll use their settings.

That said, some advanced Retroarch overrides or settings cannot be synced and might cause issues. To prevent possible problems with netplay and desyncing, it's advised to have a clean Retroarch state. If in doubt, deleting retroarch.cfg and \Retroarch\config\ will usually fix this (make backups before deleting anything). Custom controller bindings however are safe.

Changing any Retroarch settings while EmuVR is running will not be synced to other players and can cause a desync.

Game Saves

When hosting, all games will use your local save data. If a client has the same game, this will not overwrite their own saves on their machines.

As a host, any save will be committed to your files, even if a client is playing the game, so be careful. A friend could start a game and overwrite your local saves, so make backups if needed.

Performance

While enabling netplay mode has a negligible impact on EmuVR's performance, Retroarch's netplay will use more resources depending on the core and game.

Most older and 2D systems won't have a noticeable increase on CPU and RAM usage.

Some cores however will have a dramatic impact as soon as you enable netplay mode.

For example, Beetle PSX can increase RAM usage from 800MB to 3GB and double CPU usage instantly when enabling netplay.

In the same way, Mupen64Plus can increase RAM usage from 1GB to 3GB and CPU usage can increase 5 times.

These numbers depend on the game and core.

If you don't have a lot of RAM, avoid trying to play too many PS1 or N64 games at the same time with netplay.

Some cores do not support netplay at all but will still use a huge amount of RAM if you try to run them. MAME, Dolphin and Play! can eat 8GB of your RAM instantly. Since they don't do anything in netplay besides eating your resources, we're manually disabling these cores if you enable netplay, as any remote player could simply start one of these games and crash your own machine if you don't have enough RAM.

Notice that every running game will be using resources on every player's machine, even if you're not controlling it. If someone behind you starts a N64 game, your machine will load up that extra CPU and RAM even if you haven't noticed it.

Again, most 2D games are fine, and we've tested around 15 simultaneous and synced games in netplay mode with several players in the room, including a couple of PS1 or N64 games here and there.

Desync

In some rare instances, you might experience a game desync.

This means that, while the game is still running on both machines, and you're still receiving and sending button presses, the game state has diverged between you and your friend, and you're not seeing the same events happening in the game, unknowingly.

Think of it as if a tiny but decisive event somehow had different outcomes for either of you, and this forked the timespace into two different parallel universes that keep going on each machine.
You will walk (press) forward in both universes, but while you're walking along a sidewalk on your own version, in the alternate universe others might see you crossing a dangerous street, or maybe walking into a wall, but you are walking forward.

This is rare, but a little bit more prone to happen with some N64 or light gun games than others.

For example:

• You're playing a Mustached Plumber Kart game with a friend, you're head to head.
• Someone shoots a red shell in your direction.
• For some reason, maybe bugs cosmic magic, you see the shell hit your friend, but on their machine they actually see the shell hitting you.
• After that outcome, you win the race, but to your friend, they won the race.
• Following this, you might see them running into walls or doing random things, as if they're playing while blindfolded. And yet they look happy. The reason is, on their machine, they're actually at another place in the track, maybe even on a different track, doing great, while you're the one doing weird things.
• In the end, you both will think you won, but everyone loses.

There's no warning or way to notice you've desynced. If you want to help us to learn which systems or games are more likely to trigger this issue, the only way to know is to keep communicating with your friend and asking "What are you seeing on the screen?", "Are we doing this thing in this place in this level?", "Have I just won?", "Have I just died?", "Wait, you're saying you just beat me, what?"

If you're winning but your friend sounds like they've just won while running randomly into walls, ask why.

Troubleshooting

First and foremost, make sure your issue is actually related to netplay.

To confirm this, disable netplay mode (by clicking Stop Hosting or Disconnect) and try your game again. If the issue persists, it's not netplay related, then please read the General Troubleshooting page and do not use #alpha to troubleshoot unrelated issues, use #troubleshooting.

For the third time: check if your issue still happens while *not* in netplay, and if it does, do *not* use the #alpha channel, use #troubleshooting instead, after reading General Troubleshooting.

Netplay related: #alpha
Not netplay related: #troubleshooting

Important: If you have any issues, pay attention to the Log Panel in the Netplay Menu to see helpful messages and solutions to your problems.

No one can join my room / I can't connect to a host

Make sure the host has forwarded all the needed ports correctly and set their firewall rules as explained here.

When starting any game as a client, it takes several seconds to load, often freezing EmuVR

This means the Host hasn't forwarded their TCP ports correctly, or hasn't allowed Retroarch.exe on their Firewall rules. It's not your fault. Let the host know.

Some games won't load, and the console just turns off instantly

MAME, Dolphin and Play! do not support netplay at all but still can use more than 8GB of your RAM, so they're disabled while in netplay, as explained here.

If you're not using any of these cores, and they're taking 3 seconds to turn off, and you made sure it still happens even with netplay disabled, this is not a netplay issue.

The console stays on, but there's nothing on the TV

This means you don't have the same game as the host, look for an orange icon on the cartridge / CD to confirm.

It can also mean you don't have your BIOS, or for any reason your game is not working on your machine but is loading for other players.

If the game does load but for any reason Retroarch crashes or shut down only on your machine, you'll have a blank image on your TV, but the console will stay on. You can try turning the console on again locally, and it should load and sync to the host seamlessly. If this never brings the game back, your game is simply not loading, for the reasons mentioned above.

How you can help

1. Please read this wiki with attention before troubleshooting in #alpha. (Do not use #troubleshooting for netplay-related issues in this alpha.)
2. Check the new posts and pinned messages on #alpha-announcements for some quick or advanced tests we might need your help with!
3. Have fun!