An interesting take on light gun technology

[BadMouth]

From the "I should have thought of that" file.....

I just got back from a gun/outdoor show where these guys had a booth set up: http://www.lasershot.com/index.php

Basically, when you pull the trigger the gun shines a laser on the projection screen and a stationary camera looks for the bright red laser dot.
What I like about this is that it doesn't matter where the gun is or what angle it is held at, the laser dot is going to be where the gun is aimed and that is where the shot will register.  Seems to me like this concept should be a lot more accurate than having the camera inside the gun like the currently available IR setups.  The downside is that the camera needs to be mounted away from the screen, but I'd mount one on the ceiling if it meant accurate light gun play.

I talked to two different guys at the booth at different times during the day.  One only knew the basics about how it worked and the other seemed to know a lot, but was reluctant to give me any details.  I asked if it would work with other software or if it was being seen as a mouse on the PC.  He said they were coming out with a new product for around $500 that would work with flash games and such, but it wasn't on the website yet.  He seemed very confused by my questions.  I explained CRT and IR guns to him and I think that just confused (or annoyed) him more. 

Anyways, this is BYOAC!  I have a few cheap laser pointers from shwag bags and can rig them up to pulse when I pull a trigger. 
Autohotkey has a mouseclick command which will post a mouse click at whatever screen position is entered (for the system mouse anyway= only 1 player).

Anyone have any thoughts about tracking software to detect the red dot and pass coordinates?
Is there already something out there that converts laser pointer input to mouse input?  I can see that being useful for presentations and such.

EDIT: found another business card in my wallet.  There were actually 2 vendors there with this setup.  I'm pretty sure this one is the one that said they were coming out with the $500 setup, but it wasn't on the website yet: https://www.laser-ammo.com/

[Howard_Casto]

It's a clever idea, but not without some major drawbacks. 

First off lag.  There is a reason the wiimote cuts out all but the IR spectrum and has it's own internal processor just to detect dots.  Image parsing software is typically slow the higher the resolution you go.  And of course low resolution means choppy movement.  Secondly you have to worry about reflections/refractions.  Some monitors and bezels absorb the laser light enough to make it a dot, others reflect/refract it all over the place.....  especially at odd angles.  You are also going to have to have some pretty fancy software to compensate for the crazy angle you'll have to put the camera in to get and whole screen in view while players are standing in front of the cabinet.  Lastly you've got to worry about your eyes as laser lights aren't exactly healthy. 

A camera tracking a stationary dot array = wiimote.  A moving dot array being track by a camera = ps move.  This sort of thing is in that family. 

Look for webcam tracking software.  There are a few examples out there but I doubt they are fast enough or of a high enough resolution to replace a light gun, even compared to the wiimote/move. 

[BadMouth]

Yeah, did some quick experimenting.  My upright cab is a total mess when you shine the laser at it.  Got a crisp reflection of the laser source, plus reflections on the bezel plexi, the monitor, and maybe some reflections of reflections.   

I still have a rear projection tv in my living room.  It's much more workable.  The laser source is reflected, but it's a large fuzzy blob.  The only crisp red dot is where the laser is pointing.

At the show, the camera was a few feet in front of you at about waist level.  Might be workable with a pedestal CP.

I did a little bit of googling.  One discussion mentioned adding a bandpass filter that would only allow the camera to see the spectrum of the laser.
That would cut down on image processing load.  They also make IR lasers...

A camera tracking a stationary dot array = wiimote.  A moving dot array being track by a camera = ps move.  This sort of thing is in that family. 

The problem with both of those is that the calibration changes slightly based on the height and angle the gun is held at.  If a tall person calibrates it then hands it off to a child to use, the calibration will be way off.  This method is detecting where a dot is on the surface of the screen.  The height and angle the gun is held at is irrelevant, so calibration is good no matter where you are aiming from.

While I dream of a pinpoint accurate solution for flatscreens, I don't have time to mess with it much.
If I find somewhat plug and play software, I may find a spare hour here or there to experiment.

[Howard_Casto]

The only way I could see it done would be so awkward nobody would bother.  You'd have to use a lens filter like you were talking about.   You would also have to make the bezel glass out of something non refractive  and possibly put the camera between the monitor and the glass, pointed at the bezel.  That would eliminate the people problem.  So you'd essentially have to gut a projection tv and put a flatscreen in the back.   I'm honestly not even sure that would be viewable. 

I think the issues with the wiimote at least could be compensated for if you used a wiimote plus.  Since they have a true gyroscope, you know the angle the wiimote is tilted at.  Combine that with the ir position and you've got a vector.  I'm just not nearly good enough at geometry to figure out how to put it together. 

You know, captain power might have had the right idea.  It worked closer to how nes zapper worked.  Bullets flickered at one frequency of light, targets another.  They used a light sensor to decode it.  Now that won't work on a lcd, but using a standard webcam to decode the flashes, that'd work just fine.  Of course it's useless for existing games, they'd have to be re-written. 

[BadMouth]

Found another business card in my wallet, which jogged my memory.  There were actually 2 vendors with the laser stuff.
This is the one that said they were coming out with a $500 setup that would work on flash games, etc. https://www.laser-ammo.com/home.php


(only a little fear mongering  )

Their current setup is much simpler and uses a standard webcam.
I can see this being possible with off the shelf software, but cardboard targets aren't as fun as arcade games.  (at least not with fake ammo)


On all the demos I've seen of a laser dot translated to mouse position on a projected image from the PC, the image is light and washed out looking.
There's probably a reason for that. 

[yotsuya]

Rep for you for doing all this investigation, BM. Kudos!

[twistedsymphony]

I guess I don't understand what the problem is with IR LED based systems... I mean that's what the arcades have used on all the rear-projection rigs since the 90s and I don't recall them being any less accurate than CRT systems.

[pbj]

In my experience, the IR guns don't do well on the edges.  Arcade games tend to put the targets along the edges of the screen.  Gun games well suited to the Wii focus more on centrally located targets.  The limitations of IR guns on arcade games become clear very quickly.  I think your best bet is either a PS2 with a GunCon and a CRT, or a Wii with a Crossfire and a widescreen.


 

[BadMouth]

I guess I don't understand what the problem is with IR LED based systems... I mean that's what the arcades have used on all the rear-projection rigs since the 90s and I don't recall them being any less accurate than CRT systems.

When they switched to IR systems, they made the games a lot more forgiving to make up for the IR guns not being as accurate.
I'm guessing Sega's system that uses more IR LEDs is more accurate than what is available to the home consumer, but I don't have any experience with it.

Use an Aim-Trak or Wii controller, turn off the on-screen crosshairs and use only the gun sights.
Now see if the shots are aligned with the gun sights on all parts of the screen. 
Unless you can hold the gun exactly where it was when you calibrated it, they will be off.
Now pretend you're a friend that's 6 inches shorter than yourself and hold the gun lower...it gets a lot worse.

IMO, IR guns just aren't good enough to be useable without on-screen crosshairs. 
But having to look at on-screen crosshairs instead of the sights on the gun makes it feel like I'm playing with a magic wand instead of a gun. 
People who grew up playing wii would probably fine with that, but it absolutely ruins the experience for me.
The controller might as well not even be gun shaped.

I have an old CRT TV setup that I'd like to get rid of, but I keep because of the light gun games.
The ActLabs guns that I use with it are accurate to within 3 pixels no matter where you are standing.
You can move around, swing the gun side to side to shoot enemies on each side of the screen...whatever.  It just works.

[twistedsymphony]

In my experience, the IR guns don't do well on the edges.  Arcade games tend to put the targets along the edges of the screen.  Gun games well suited to the Wii focus more on centrally located targets.  The limitations of IR guns on arcade games become clear very quickly.  I think your best bet is either a PS2 with a GunCon and a CRT, or a Wii with a Crossfire and a widescreen.


 

No doubt that the Wii IR setup blows I have problems with that all the time.


The way the Wii (and most crappy 3rd party IR Guns setups) work they only use 2 or 4 LEDs total and need to "see" at least 2 of them at all times in order to track properly, with the Arcade setup.

I worked as an arcade tech for a few years while in college.  Most of our light games were CRT based but we had a rear projection Jurassic Park shooter as well as a Rear Projection Time Crysis 2.

IIRC they had IR LEDs along the entire parameter of the screen about every 6 inches or so....  this means that as long as you could see at least 2 of the LEDs on any side of the screen you were good. The only time you'd have problems would be in the dead center of the screen if you were too close (but that's stops cheaters anyway  ) which is why those machines had a pedestal to ensure that the player was far enough back.


I used to calibrate all of the gun games once a week as part of my maintenance routine and I never saw anything that led me to believe the IR based stuff was any more forgiving than the CRT guns; aside from the fact that with a bigger screen you obviously had bigger targets.


I believe that most IR systems can handle extra LEDs... so it couldn't hurt to just tape a bunch up around the parameter of your monitor and see if it helps. With most systems they're really not doing anything special.

[BadMouth]

My comments about newer games being more forgiving are based on playing NAOMI games like Maze of Kings on the Demul emulator.
The targets seem so easy to hit that the game gets boring.
That's my opinion.  Can't say that I've done any systematic testing.

That game used an IR setup like what you are talking about.



I would completely outline my monitor in IR LED strips if it meant accurate light gun play on my LCD cab.

[twistedsymphony]

My comments about newer games being more forgiving are based on playing NAOMI games like Maze of Kings on the Demul emulator.
The targets seem so easy to hit that the game gets boring.

I've never played Maze of the Kings (or any NAOMI shooter) but a lot of games show you where your bullet landed, or if not the test menu usually has an option to show you where you're aiming at all times and is a good indication of the gun accuracy.

As for the forgiveness It might have have to do with the difficulty a lot of times on shooter that will directly affect the size of the hit boxes.

Maze of the Kings was also available as a CRT upright:


I would suspect that if they needed to be more forgiving on Ir setups then there would be an option in the settings to switch between IR and CRT gun modes to adjust the hit boxes.

I would completely outline my monitor in IR LED strips if it meant accurate light gun play on my LCD cab.

It couldn't hurt to try. It only works with Wii style setups with the sensor in the gun and the IR LEDs DO need enough space between them that the gun sees them as distinctly separate light sources.


EDIT: I just noticed that CRT Maze of Kings looks like it's using IR LEDs too... I don't think I've ever seen IR sensors on a CRT game like that... though I suppose that says something about Sega's confidence in that system.

I wonder how hard it would be to use a IR arcade setup on a MAME PC.

[Howard_Casto]

The wii guns are incredibly accurate, if calibrated correctly, and you don't move around a lot and you aren't playing in a cab.  When I wrote the glove pie scripts I got it to where I could play the old-school lightgun games with the crosshairs turned off no problem.  Now I re-calibrated after entering every single game, but that's the price of doing business unfortunately. 

Notice where the arcade ir setups are on podium cabs where the monitor is fully upright and the podium makes the player stand back far enough to where the entire led array can be seen at any angle?  THAT is the key to a good setup. 

With a standard style arcade cab you are standing too close for the wiimote to see the sensor array at all times.  You are also shooting at an angled monitor which makes the calibration differ depending on your height.

I guess what I'm trying to say is that at lot of these issues arise because we are trying to shoe-horn a technology into an application it wasn't designed for.  If you build a cab like the one you linked to from the ground up, you'll get an accurate rig... wiimotes can actually track up to 16 separate leds at any given time.  You would have to write the code manually, but it would be as simple as determining which leds are the corner ones and taking the average of those dots.  The average of those dots is dead center every time, no calibration would be needed.  But you've got to be standing far enough away to where those dots are always in view of the camera. 

[twistedsymphony]

The wii guns are incredibly accurate, if calibrated correctly, and you don't move around a lot and you aren't playing in a cab.  When I wrote the glove pie scripts I got it to where I could play the old-school lightgun games with the crosshairs turned off no problem.  Now I re-calibrated after entering every single game, but that's the price of doing business unfortunately. 

Notice where the arcade ir setups are on podium cabs where the monitor is fully upright and the podium makes the player stand back far enough to where the entire led array can be seen at any angle?  THAT is the key to a good setup. 

With a standard style arcade cab you are standing too close for the wiimote to see the sensor array at all times.  You are also shooting at an angled monitor which makes the calibration differ depending on your height.

I guess what I'm trying to say is that at lot of these issues arise because we are trying to shoe-horn a technology into an application it wasn't designed for.  If you build a cab like the one you linked to from the ground up, you'll get an accurate rig... wiimotes can actually track up to 16 separate leds at any given time.  You would have to write the code manually, but it would be as simple as determining which leds are the corner ones and taking the average of those dots.  The average of those dots is dead center every time, no calibration would be needed.  But you've got to be standing far enough away to where those dots are always in view of the camera. 

Quoted for Truth 

As I said earlier my only problem with the Wii remote setup is the remote not seeing the IR LEDs... accuracy is fine.

Personally if I were to build a shooting cab I'd base it on the mid-90s Sega cabinet used for Virtua Cop/HOTD


It's a fairly compact design and the mirror setup gives you more depth than the actual depth of the cabinet to keep it challenging, not sure how well IR would work in something like this (I'd assume just fine as long as the interior of the cabinet was properly matted out).