Help with ViewSync/yawOffset & ViewSync/pitchOffset settings

[Mike Breton]

Hi,

 

I'm setting up a new 8 screen liquid-galaxy display (4 wide x 2 tall) and need some help getting the Offsets correctly.  I'm using multiples of 36.5 and things look ok left to right (although I'm seeing the edge of the earth moreso on one side than the other) but the top/bottom screens are no matching up correctly.  They look like they are zoomed out but when you zoom in you relalize there seems to be part missing between the upper and lower monitors.

 

Any suggestions / help on these settings?

 

Also, my "wall" is flat so is there a suggestion as to what I might set the ViewSync/horizFov to to better flatten the display and get rid of the strong curve shown on the screen furthest from the master?

 

Thanks!

 

-Mike Breton

[Adam Vollrath]

The ViewSync functionality built into Earth is designed for displays on the inside of a sphere (or cylinder if it's only one row).  So there's no support for translating the camera sideways, and combining yaw and pitch offsets won't line up the two rows exactly.

To work around this on our flat installations, we configured Earth to use very narrow FOV's.  You might try setting the horizFov to 8.0 and the yawOffsets 8 degrees apart.  This should provide a total field of view of 64 degrees for all eight screens.  This will also help with the issues you're seeing between the two rows, but it's simply not possible to accurately portray the inside of a sphere on a flat surface.

Also, be aware that this may narrow FOV may cause Earth to behave strangely. Icons may be much larger, and rotating the camera will swing much quicker than before.

[Andrew Leahy]

Yup, curved walls is what Liquid Galaxy is designed for.

Besides setting a narrow field of view (ViewSync/horizFov) there are ways to simply "stretch" a single Google Earth window over multiple screens.

Mike, what's driving your flat tile wall?

eg. 8 PC's, 4 PC's with dual-head cards, 2 PC's with quad cards, 1 PC with multiple quad-cards?
What operating system?

The attached shows a single Google Earth running in a 3x3 HD rear-projection tile-wall at my uni. This is from 2008 so it's GE4.3. Note the vignetting effect (dark edges) you get when you're not perpendicular to the projector light source.

Andrew
eResearch / Uni of Western Sydney

[Mike Breton]

Thanks to you both for the quick reply.  I think we've got it looking pretty good now.  Here are the details.

 

8 Intel Core i5 2nd gen systems running Windows 7 and GE 6.2.1.6014 (beta)

8 55" LCDs (Samsung Ultra Thin Bezel) / 4 wide x 2 tall

 

The yawoffset is in multiples of 8 with the 2nd screen in from the left at 0.0 so screens are set as follows from left to right:

8.0     0.0     -8.0     -16.0

 

I tried the suggestion of using 8 for the pitchoffset but it was too much so I reduced it via trial and error to 4.75 (for the bottom 4 screens.  the top are at 0.0)

 

All 8 screens are in pretty good sync now regurdless of zoom.

 

Is there anyway to postition the navigation center?  I'd rather it be respecitve to the center the of the 8 screens vs. the center of the master system.

 

Thanks!

 

-Mike

[Adam Vollrath]

I don't think we suggested a pitch offset of 8. You'll need to estimate using your screen aspect ratio, which is likely close to 16:9. But because of the spherical overlap, even that won't be precise, so experiment with whatever looks good.

To get the navigation in the center, we sometimes have the "master" on a separate system, either hidden or displayed on a podium. Also, this is  one reason we design new LG's with odd numbered dimensions.

[Mike Breton]

ah, I misread your yawoffice suggestion of 8 as applying to both yaw & pitch.  No worries.  the 4.75 seems to be working well.  Good idea regrind a unseen "master".  I was thinking of something like that as we're using a Kinect to control and I really wanted another screen so people could see the skeletal overall.

Thanks again!

-Mike

[Stuart Engelhardt]

Adam is correct - odd numbered systems are the way to go. While our initial system at Johnson Space Center was 8 displays, we ended up splitting it into two test units of 3 and 5 displays each. And the one I built at NASA HQ last month was 9 displays.

The master machine (ViewSync/send=true) does not care what values you enter for the offsets, it ignores them all and stays 0,0,0. But as Adam mentioned, you can run Google Earth on a separate system, and then set your first two monitors on each side to half the offset, thus overlapping the master and giving you the effect you desire. In which case you'd go with something like this:

Left 2, Left 1, Master (hidden), Right 1, Right 2
12, 4, 0, -4, -12

This would keep your offsets 8 apart from each other, and effectively overlay the hidden master, which you could then use as the touch screen / podium overview / etc…

[Andrew Leahy]

As long as the viewsync/sender (master machine) is outside the display wall then tweak the yaw and pitchOffsets to "center" the view at the cross-join in the middle of the wall.

Something like (yaw, pitch)

[-12,+4.75]  [-4,+4.75] [+4,+4.75] [+12,+4.75]
[-12,-4.75]   [-4, -4.75] [+4,-4.75]  [+12,-4.75]

Personally (if you're sticking with Windows), I'd investigate simplifying the setup with two machines with quad-head cards (and repurpose the other 6 machines!). Maybe something like http://www.nvidia.com/object/product_quadro_nvs_450_us.html. I haven't used this particular card but the earlier NVS cards were "okay" for GL apps. If you wanted to run Linux/X11 it's fairly straightforward to merge systems into a large flat virtual desktop. But I don't know what you're other uses/applications are.

Send us pictures :)

Andrew

--
"Those who know, do not speak. Those who speak, do not know." (Lao Tzu)

My household GHG emissions from energy & transport ~4kg CO2e/day or ~1.4tonnes/year
Household daily use of Water 110L, Electricity 3.9kWh, Petrol 1.2L, Gas 0MJ

[Mike Breton]

Thanks for the suggestions. I had to change things a bit as the yaw
goes + as it moves to the left of the master, not -. Also, we needed
to half the 4.75 I was using to get my vitrual master centered between
the upper and lower rows. This is what I have in place now and it
looks great.

[12,+2.375] [4,+2.375] [-4,+2.375] [-12,+2.375]
[12,-2.375] [4, -2.375] [-4,-2.375] [-12,-2.375]

Here are a few links to some photos:

http://dl.dropbox.com/u/77534/IMG_0571.jpg
http://dl.dropbox.com/u/77534/IMG_0573.jpg
http://dl.dropbox.com/u/77534/IMG_0575.jpg

Thanks for your help.

-Mike

On Feb 13, 5:34 pm, Andrew Leahy <alf...@gmail.com> wrote:
> As long as the viewsync/sender (master machine) is outside the display wall
> then tweak the yaw and pitchOffsets to "center" the view at the cross-join
> in the middle of the wall.
>
> Something like (yaw, pitch)
>
> [-12,+4.75]  [-4,+4.75] [+4,+4.75] [+12,+4.75]
> [-12,-4.75]   [-4, -4.75] [+4,-4.75]  [+12,-4.75]
>
> Personally (if you're sticking with Windows), I'd investigate simplifying
> the setup with two machines with quad-head cards (and repurpose the other 6

> machines!). Maybe something likehttp://www.nvidia.com/object/product_quadro_nvs_450_us.html. I haven't used

> this particular card but the earlier NVS cards were "okay" for GL apps. If
> you wanted to run Linux/X11 it's fairly straightforward to merge systems
> into a large flat virtual desktop. But I don't know what you're other
> uses/applications are.
>
> Send us pictures :)
>
> Andrew
>

> On 14 February 2012 11:26, Adam Vollrath <axisofentr...@gmail.com> wrote:
>
>
>
>
>
> > I don't think we suggested a pitch offset of 8. You'll need to estimate
> > using your screen aspect ratio, which is likely close to 16:9. But because
> > of the spherical overlap, even that won't be precise, so experiment with
> > whatever looks good.
>
> > To get the navigation in the center, we sometimes have the "master" on a
> > separate system, either hidden or displayed on a podium. Also, this is  one
> > reason we design new LG's with odd numbered dimensions.

> > On Feb 13, 2012 7:04 PM, "Mike Breton" <msbre...@gmail.com> wrote:
>
> >> Thanks to you both for the quick reply.  I think we've got it looking
> >> pretty good now.  Here are the details.
>
> >> 8 Intel Core i5 2nd gen systems running Windows 7 and GE 6.2.1.6014 (beta)
> >> 8 55" LCDs (Samsung Ultra Thin Bezel) / 4 wide x 2 tall
>
> >> The yawoffset is in multiples of 8 with the 2nd screen in from the left
> >> at 0.0 so screens are set as follows from left to right:
> >> 8.0     0.0     -8.0     -16.0
>
> >> I tried the suggestion of using 8 for the pitchoffset but it was too much
> >> so I reduced it via trial and error to 4.75 (for the bottom 4 screens.  the
> >> top are at 0.0)
>
> >> All 8 screens are in pretty good sync now regurdless of zoom.
>
> >> Is there anyway to postition the navigation center?  I'd rather it be
> >> respecitve to the center the of the 8 screens vs. the center of the master
> >> system.
>
> >> Thanks!
>
> >> -Mike
>
> --
> "Those who know, do not speak. Those who speak, do not know." (Lao Tzu)
>
> My household GHG emissions from energy & transport ~4kg CO2e/day or
> ~1.4tonnes/year

> Household daily use of Water 110L, Electricity 3.9kWh, Petrol 1.2L, Gas 0MJ- Hide quoted text -
>
> - Show quoted text -

[Andrew Leahy]

Mike, great pictures.

If this isn't a permanent setup (looks like a setup for a conference or large retail outfit), next time I'd suggest a 6x1 configuration with the screens rotated to portrait.

This will give 6480x1920 (12megapixels raw) and an aspect of 3.375:1 (ignoring bezels).
+ it's about the same size as the 4x2.
+ IMO portrait walls are still novel and likely to attract eyeballs over standard video walls! (if that's the purpose)
+ will have LESS bezel encroachment, as a fraction of the display area
+ allow the screens to be on a slight curve, which suits Liquid Galaxy much much better.
+ will only show the Google Earth menu bar along the top of the display
+ it's much easier to physically mount a single row of screens. grids are a pain to align properly!
- doesn't have as many pixels. The 4x2 is 7680x2160 (16megapixels) displayed pixels, 4x2 aspect is 3.55:1 (slightly wider than 6x1). Notice there's only 240 pixels difference in the vertical direct (1920x2160), about 10% difference
- 6x1 isn't ideal because there's not a complete middle screen, but you already are familiar with that problem with the 4x2.

A 5x1 or 7x1 could be options... depends what the purpose of the wall is and available space.



So what we need now is Liquid Galaxy branding and business cards/flyers, so people who see these know where to go to build their own!

Andrew

eResearch / Uni of Western Sydney

[Mike Breton]

Thanks for the suggestions. For now, we'll keep the wall as is as we
use it for many other demos where full screen Windows desktops are
shown and or the demo calls for a 16x9 display format. In addition to
the GE demo, we also have the HTML5/WebGL Aquarium demo and are
looking at adding a couple of other synchronized display demos.

I guess I should supply some background. This wall is in the Intel IT
Innovation Center in Folsom, CA. The IT Innovation Center is part
lab, part technology showcase, and executive briefing conf room. The
showcase is open to Intel employees all day long and visited by
external customers usually daily as part of other meetings they are
having in the conf room. We inititialy setup the video wall to
replace lots of 1:1 systems/display demos while providing a larger
canvas but the new syncronized display demos have been getting most of
the attention as they look so darn cool! :)

Thanks agan for all the suggestions and for helping me get the GE demo
added to the wall. It really looks good. By the way, we have some
initial gester controls in place via the Kinect (using FAAST) but
we're process of writting our own Kinect interface via the MS SDK.

-Mike

> > > >> -Mike- Hide quoted text -

[Jason Holt]

That sounds really neat.  We've been talking about using a kinect instead of the space navigator.  Maybe you could open source your code?

[Mike Breton]

I think that's a possibility. I'll be back once we have it working.

-Mike

> > > - Show quoted text -- Hide quoted text -