Laser Projectors - Status

[sagrada737]

Hello All,

I wanted to share progress on the Optoma ZH406ST laser projector installation for my 210 degree wrap around display. 

As I had mentioned before, my display is setup in an NVIDIA Surround Mode, with a combined 3 projector resolution of 11,520 x 2160.  This is processed by the Pixelwix warp/blend software, which is then handled by an NVIDIA RTX-3090 GPU, and output to each laser projector via a Display Port to HDMI cable.  The laser projectors are capable of receiving 4k resolution and down-scaling it to 1080p HD resolution. 

The benefit here is that the approx. 30% loss of graphics data as a result of the warp/blend process, is negated by the down-scaling within the laser projectors, which allows full HD resolution to be displayed on the projection screen.

Before...   The laser projector setup was generally working fine and the display quality was great.  However, during a typical flight, I had noticed that one or more of the projected displays would shift by about an inch on the screen.  The display was coherent, but that entire sector would shift, then typically correct itself after about 2 to 10 seconds.  This was noted in the blended area where the projectors would overlap.  This was not a huge problem, as it happened only about 10 times during a flight, typically during a turn in-flight or on the ground.

After quite a few test flights, trying to determine where this problem was coming from, I discovered that the more addon functions I had running on the single Sim Computer, the more I would see this "display shift".  This is one reason why I decided to build a up-to-date faster Sim Computer using an Intel i9 11th generation CPU and other compatible system components.
That Sim Computer build is still in process, with the i9 CPUs on back order from Intel.  Hopefully I will take delivery of the CPU in a few weeks.

In the mean time, I noticed in my testing that whenever I had the 6dof Motion Platform Servo hardware OFF, that the display shift did not take place.  When the Motion Platform Servos were active, the display shift would occur.  This was further compounded by having ActiveSky running.  Everything pointed to limited CPU throughput.

Long story short...  I next did two things that have seemed to resolve the display shift problem.
1.  I disabled in the BIOS -- Intel Virtualization Technology.
2.  I increased the OverClocking of my i7 CPU from 4.2 GHz to 4.7GHz.

The Intel Virtualization Technology setting in BIOS is somewhat subjective, whether or not it is enabled or disabled.   Most state that it doesn't make any difference, but it MAY depend on the system configuration whether it helps or hurts.  In my case, as confirmed by flight testing, Disabling Intel Virtualization Technology reduced the display shift problems by about 90%.  I don't know why -- it just did.

I then increased the i7 CPU Clock Speed to 4.7GHz in the MSI's Motherboard Game Mode.  I used the standard Over-Clock Profiles provided by MSI to ensure safe over-clocking of the system.   That increase in system speed seems to have completely eliminated the display shift problem in-flight and on the ground, even at HD airports.

When the new Sim Computer is ready to install, I will elevate both the Flight Model Computer and the Sim Computer, which will allow me to use a shorter HDMI Cable, going from the 25' cable I am currently using, to a 15' Display Port to HDMI cable for the new system.   Long HDMI cables can be a source of display problems with 4k+ systems, so changing to a shorter, high frequency HDMI cable should help improve reliability.  This is important, as the six high-power Servo motors can generate EMI.  Since these Servos are very near to the Sim Computer, using a high quality shielded HDMI cable will help.

I should mention that in a static mode, that is, when the 6dof Motion Platform is not operational, the 210 degree wrap around display remains quite stable, as the three projectors are not subject to Platform movement and associated vibration.  However, when the Motion Platform is active, there is considerable movement and low frequency vibration.   This causes the projectors to move very slightly out-of-alignment.  Not by much, but just enough to bug me.  To correct this, I have placed dampeners at each corner of each projector.  This results in maintaining improved projector alignment during Motion Platform operation.

Anyway...   That's the status of the Laser Projection setup.  As is the case with our Sim Projects, there is always something that needs attention as we strive to get everything working correctly.

To give you an idea of the scale of the Sim and 6dof Motion Platform, here is a recent photo.   I am now in the process of adding the AFT part of the Flight Deck, which I hope to have completed in a month or so.

Onward, and Upward,
Mike

[brianwilliamson]

Gooday Mike, very interesting information. I still have not put my 10900K together yet, as I am waiting for the release of the new Video cards, as there appears to be that much hype and rubbish published about their release, that it is hard to believe anything that is printed !

Looks as though the CPU still poses the main problem with glitches, but suspect you will have fixed that.

Cheers........Brian W.