Info on how Terminator salvation gun works

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Zebra:
For anyone interested in how Raw Thrills IR guns know where you are aiming, the super deluxe manual goes some way to explaining the mystery of the 10 - 12 led monitor sensors:

https://rawthrills.com/wp-content/uploads/manuals/t4_sdlx_manual.pdf

Some here had assumed that there was a mechanism for the computer to know exactly which of the 12 led boards the gun was pointed at. According to the manual, this is not the case. The led's are placed around the screen to form a rectangle of led lights. When you tilt the gun to aim, the camera catches changes in the orientation of that rectangle. After calibration, that orientation is enough to accurately capture what the gun is pointed at.

It sounds fairly similar to the way the Sinden gun works except with led lights instead instead of the white screen border.

Howard_Casto:
That's a good find but I don't know if it is particularly helpful. The camera used for the samco and wiimote do all of the dot detection automatically and can only track 4 dots at a time. Considering how many leds the bezel has they must be tracking more than that... it might be what the fpga is for, I dunno.

Zebra:

--- Quote from: Howard_Casto on November 25, 2019, 10:44:44 pm ---That's a good find but I don't know if it is particularly helpful. The camera used for the samco and wiimote do all of the dot detection automatically and can only track 4 dots at a time. Considering how many leds the bezel has they must be tracking more than that... it might be what the fpga is for, I dunno.

--- End quote ---

If I understand it correctly (and I'm not sure I do), they aren't tracking 12 led boards individually. The set-up uses smoked ir lens covers which would act like diffusers so it wouldn't be possible to see individual lights.

I think the camera sees just one object - a rectangular box of light. It then uses the orientation of the box to determine what the gun is pointed at. Kinda like if you were to try and draw a rectangle viewed from different angles, it would look different if viewed from the left than it would from the right. Plus, if you turned your head, the corners would be higher on one side than the other etc.

It's possible that we've been giving them too much credit by assuming they were tracking the gun's position relative to 12 led boards individually. I don't think they are tracking the gun's motion at all.

Using the orientation of the IR light box plus having defined screen edges seems like a simpler and more effective solution (assuming you have the capability to program it to translate the orientation to a screen position).

Further evidence, IMO, is in the circuit diagrams. It looks like only power is sent to the led boards on the monitor. Each board has four pins going in but only two are used on each board. It's different to the sega system where each led board has 6 wires going in and 6 going out to the next board. There is no method of distinguishing one led from another that I can see on Terminator Salvation.

Howard_Casto:
No it's probably not seeing the entire screen unless you stand 20 feet back. Even with a super wide angle lens that isn't possible at a reasonable distance from a screen that large. It can probably see 1/4th of the screen at a time, which is about the same amount a wiimote or something similar can see. Besides, you are missing my point..... the inexpensive hardware we have to work with is stuff like the Samco and wiimote and it doesn't particularly matter how salvation does it unless it's something that can be replicated with them. JayBee's firmware is probably the best bet we've got to getting a decent gun with the diy route that'll work a reasonable distance away from the screen.

Zebra:
I don't see why the Raw Thrills method couldn't be replicated by someone with the right coding know-how. I.e. The knowledge to use the orientation of the led's to calculate coordinates instead of gun motion in relation to sensor bars.

I think the assumption that it is not possible for a camera to see all the led's mounted around the screen at once is wrong. Even my phone camera can comfortably see all the edges of my 77" OLED from 5 feet away, which is far closer than I would stand for a screen that large. The PS3 eye camera can also see the whole screen from fairly close by.

We also know the Sinden gun apparently works by needing to see all 4 edges of the screen. And, for the Raw Thrills method to work, their gun camera has to be able to see all 12 led's. I don't know what the limitations of the Wii camera are though. Wii remotes are very fussy with distance from the sensor bar. Perhaps there is an alternate option if the Wii camera lens is the limiting factor. Maybe it could use the PS3 eye camera instead?

Or... perhaps there is a way around the problem. If the Raw Thrills gun uses the orientation of the led rectangle to calculate aiming coordinates, the shape is more important than the need to mount led's to the bezel. Maybe a smaller led rectangle could be mounted behind the screen. I believe the led's on Terminator Salvation are mounted above and below the marquee and not around the bezel.

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