WTF - Sega Menacer working on an LCD flatscreen... How???

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lilshawn:
I mean it's not going to be every other frame or anything... Maybe 1 out of every 4 frames or so. (15 samples a second) wouldn't make the screen that obviously bright. This could be compensated for after by making sprites unreasonably dark.

But really... The patent is right there... It explains how it works.

lilshawn:

--- Quote from: Zebra on February 10, 2020, 01:03:15 pm ---why does every other light gun use a noticeable white flash? This includes Saturn and Dreamcast guns.

--- End quote ---

sorry, i totally missed this question.

to put it simply, one of 2 things... to lower the processing required to determine gun position... (we only need to calculate position if you pull the trigger.) or the inability to take control of a data line on the controller port to send vertical refresh timing signals down to do it the way the Sega GENESIS does it.. (either hardware limited or no such signal exists outside of the video subsystem.)

the flash you see when you pull the trigger is often actually a pile of 7 to 10 separate white screens bundled together. (black white black white black white etc.) you throw out any weird readings high or low and take maybe 5 of the closest ones and average them to determine the position.

you can actually see this on the gun test screen of Big Buck Hunter Pro arcade. (which is also does continuous tracking) if you pull the trigger and hold it down, you can see on the monitor ALL the samples it took, where they are, how many where used to calculate position.
EDIT:

i snapped a pic of a standard BBH pro cabinet gun test.... it's bad as the screen is strobing really bad to the camera (likely every other frame), but will give you the idea of how almost all optical guns operate...

here on the test screen it just appears as a medium white screen you can see there are several pixels showing approx. how many samples were taken (orange)...and how many where used (blue) to determine the gun position. the software also constantly updates and tells you how many scanline samples where taken (in this case it looks somewhere between 12 and 14 samples) and how many used (looks about 3 or 4)

in this case, the gun positioning is completely handled by the IO board of the cabinet and not by the game computer. the VGA comes out of the computer and into the the IO board and out to the monitor... it reads the vertical refresh pulses from the sync and then handles timing flashing the screen...counting the timing during refresh after the trigger pull...reading how long it takes for the opto to pick up the scanline... then reporting that to the computer. that way the game need not have to delay doing game stuff to figure out position.

most gun games work in this fashion. with the exception being very early games that simply register hit/nohit (early atari, NES etc) and later camera guns (wii , namco camera guns, aimtrak)

the technology at the time of the menacer was just not available to have real time tracking. the genesis had an 7.6 mhz CPU, how much realtime ANYTHING could be done with 8mhz? around 1998 HOTD2 started using cameras on the DX cabs to track positioning but we were looking at a 50mhz sega model 2 board (with 3 other seperate CPU systems to handle graphics, sound and what nots so the CPU wasn't actually doing much else) at the time to do this. by 1999 Crisis zone deluxe cabinets where using a B/W camera and a weird infrared dot projector gun and a custom FPGA to do the heavy lifting of figuring out gun position. not going to happen with an 8mhz cpu having to do everything else too.

Zebra:
All the Big Buck Hunter Light gun versions I have seen (including pro) flash when you pull the trigger. This means they are regular light guns and we know how they work already.

The question is about how the Menacer differs. None of the others can move a crosshair over a black screen (or any dark color). The Menacer apparently can.

Anyway, if there is a patent for the Menacer, that means there must be something new to the design. You don't patent products unless there is a new invention or a new and unique way of using an old one. The Menacer certainly wasn't the first light gun.

I'll take a look at the patent doc but it's only going to answer the question if it describes a new tracking mechanism. I wouldn't be surprised if Sega patented that hideous two lens scope as they were under the impression it was a good idea that may get copied...,

lilshawn:

--- Quote from: Zebra on February 10, 2020, 07:20:54 pm ---All the Big Buck Hunter Light gun versions I have seen (including pro) flash when you pull the trigger. This means they are regular light guns and we know how they work already.
--- End quote ---

precisely. the reason for the flash is because it's far easier to see the difference between dark and light if the screen is always dark. bat as i updated my post... BBH also does realtime tracking with the same gun.

Howard_Casto:
Regardless, it obviously doesn't work with lcd screens or else sega would still be using it. They are the king of light gun games in the arcades these days and yet they use a different system.... there has to be a reason for that.

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