6DOF Project, design considerations

You have place outside ?

you can use the projector outside but you need powerfull light

with flyelise, you dont need to fix the projectors in the middle. It can be in the side but in the same circle. Same circle is more easy but i try bigger range in the middle and it was working good. You need to have a zoom , it s better.

Instead to fix the 3 projectors inside, you can install them outside and you ll have a bigger screen in front

Hmm, thanks for the suggestion, but how does that work? I mean, a fixed screen and a moving rig? The simulator software (XPlane) which renders the graphics doesn't know the position of the rig which is calculated in FlyPT Mover. But there has to be motion-compensation like with with VR headset. For example, when driving a left turn with a car the rig has to roll to the right to simulate the centrifugal force but the horizon has to stay level with the pilot's frame of reference so it has to roll right on the static screen.

So Fly-elise sends moving cut-outs from an even bigger "internal" screen to the actual projectors? If not, how is the rig position feed back to the simulation software?

If my assumption is true then Xplane has to render an even bigger screen. And the actual screen also has to be bigger than the visible portion. The areas at the top and bottom are only visible when pitching up or down. So I loose resolution twice. I'd also need >180° horizontal FOV because yaw motion would expose off-screen areas at the left or right which would kill immersion.

But somehow it HAS TO work.... At least the picture on the Fly Elise home page also shows a static screen an a moving simulator rig.

(Answer to @GettinBetter 's question moved to this thread because it belongs more to my personal design than to the HY450 prejector in general)

For simplicity I'll start with completely flat screens and the projectors as close to the centerline as possible. I prepare for slightly overlapping images but trim that overlap out with the digital zoom at first. This way I'm hopefully able to put it into operation without any special software like Fly-Elise at the beginning. In this temporary configuration the projectors are basically used as cost effective and less fragile replacement for flat TV/LCD screens. Of course, this is not perfect. There will be visible bevels or gaps at the edges between the seperate screen areas.

So as a second step I plan to smoothen the corners by replacing the flat screens with slightly curved ones with rounded corners at the seams. I fear a unified, cylindrical or spherical screen is not possible with the cheap projectors due to focus issues. But I can use Fly-elise or similar software to blend together the overlapping screens areas so there are hopefully no visible seams.

I know, this won't be easy, especially with a helicopter simulator with the screens moving together with the rig. I expect quite a bit of vibration, and actually, it has to be there to feel realistic. But with all 4 projectors mounted on a common base plate I'm confident that there is not much movement of one projector relative to its neighbour. And movement of all projectors together relative to the screens will be virtually invisible. If the screens shake a bit while the projectors stay still (in the reference frame of the rig) the image won't move.

If your range of moving is short, you dont need compensation.
You need to test what is your feeling with you. 10cm / 20cm / 30cm ?

This is really interesting.. I seriously want this to work out for you, as I'll be following closely behind. I'm already dissapointed with my screen setup.

Hmmm, surge and sway are not noticable at all and heave has probably no big effect either. Slow and coordinated turns are also no problem as the helicopter is hanging straight from the rotor head and the rig doesn't rolll much. But especially when training hovering you need to feel and see very small changes in roll and pitch to be able to react quickly. If you don't have compensation the look and feel doesn't match.

There has to be a solution, though. I've seen commercial simulators that use fixed screens and VR headsets also feed back the motion information to the simulator software somehow. I just don't know how it works. You need the right software.

Ah yes, I remember asking the same question before about your screen setup. But the main reason why I currently prefer a moving screen is not the space. When moving around the rig+screen need alsmost the same space as a big static screen. But I'm worried about GPU power and cost. The graphic card for the PC is by far the most expensive part. When rendering the simulated landscape on multiple screens with high reolution you have to take all power you can get. A high end graphic card is >2000€ and I've been told it still struggles to generate more than one 4k image at a reasonable frame rate.

With the big static screen you need more area because you additionally have to display the parts currently not visible. I even doubt that 6 TV screens or 3 projectors are enough. When flying a fixed wing aircraft on Sven's simulator I realized that the side windows are extremly important when flying traffic patterns. It's extremely hard to find the runway to land with just the front screen when flying VFR. You need to look sideways to know when you have to do the turns for the base and final.

Of course, with a helicopter you could just hover and turn in-position to look around but that's not realistic.

So with the 4 screens I can cover an almost 270° "panorama view" and hopefully 4 times HD (1920 x 1080) is enough which takes the same GPU power as one 4k screen. Otherwise I'd need multiple PCs and/or multiple graphic cards which gets far more expensive than the projectors.

It's not easy to find the best arrangement for the screens and projectors. But at least it doesn't seem completely impossible. But the ceiling is getting closer and closer.

After all, I don't know if I should place the actuators around the rig instead of underneath.
And I definitely have to add lots of weight to the base plate or the whole thing will tip over.

The problem with four screens in the middle line/join is bang in the point of interest view. Same problem I have with my two extra wide curved screens on my PC. I tried my rig running assetto the other day on the six screens, and the track horizon falls bang in the middle of the two rows, so you can't see the track at any distance.

Whats your idea of "reasonable" frame rate?

I'm going to add outriggers to my base...

I hope that this is less of a problem for my setup. First, there is no real gap between the screens. Of course, the seam will not be perfectly invisible. But I think it will be much better than black bevels of TV screens. Second, with two seats the center line is not directly in front of the pilot.

This issue is actually a bit more complex. In the real world the horizon is (almost) infinitely far away. So the pilot's line of sight is 90° to the windscreen. At the simulator the screens are a bit behind the plane where the windscreen should be but not very far away. So there is some sort of parallax error. On the Cessna simulator we found out that the best way to handle this is to shift the viewing angle of the front screen(s) a little bit so that the "vanishing point" (where the line of view and the horizon cross) is not exactly in the center but more in front of the pilot. This means on the other hand that the co-pilot gets a little distorted view. But you have to make compromises and choose the "lesser evil".

I haven't tested this myself but I've been told that action gamers want 100fps or more. I think, that's overkill and 60fps should be enough. With VR it's more critical because you get some sort of strobe light effect when you turn your head quickly. With a stationary screen it should be much more relaxed. I've watched TV with 25fps half of my life when cathode ray tubes were still common so I'd probably be happy with that.

Yes, I also want my simulator to stay mobile and not bolt it to the floor. So if I want I could load it onto a trailer and drive to fairs or other events.

Yes, I went for a really small bezel, which is what I got, but then there is nearly another half inch border that the picture never gets beyond. Obviously this makes the bezel much larger and irritating.

I agree with your framerate numbers, I aim around the 60 mark, any less and I can see it. I set my GPU to 60, as I don't see the point of any more.
But I always go for as much onboard gfx memory as I can afford at the time of purchase. My last gfx card was 11Gb, and the one for this rig is 16Gb. Along with four M2 VNMe SSD in a RAID 10 configuration, on a PCIe rail and using 128Gb DDR4 memory.
That should keep me out of trouble for a while.

Have you thought about ambient light vs contrast ratios with your proposed setup?

Hi
If you search on etsy with bezel camoflage bar you find them in lots of sizes
hope this helps

must be bezel kit

Which ambient light? My cabin will be completely closed with no daylight at all. The contrast of the HY450 projectors is pretty good. I know, with a circle of screens you always have some stray light or reflections between opposing screens but the extreme case with the left screen completely dark and the right completely bright won't occur, normally.

I was referring to the build up of that stray light (leaking from each projector), plus each projector adds to the ambient light level. With three projectors in close proximity, the ambient light level (reflected from screens) will be considerable. Do you not think?

I have to check that again but I think there is not much light leaking from the projector outside the screen area.

I have checked and there is really almost no light "leaking" from the projector itself. If I put "blinders" between two adjacent screens the one in the shadow is almost pitch black. However, there is some diffuse reflection from the lit screen, of course. I think this can't be avoided with dome shaped or multiple flat screens with projectors. LCD screens are black when passive but a projector screen has to be white.

I'm also a bit worried about the hot air produced by the four projectors. This is convenient in the winter but in summer the cockpit quickly becomes a hot air fryer.

Thats a relief. My projector, which is admittedly old, did leak like a sieve.

Whats the power consumption of the projectors?