Multimonitor Ruminations

[cjmaddy]

Sorry to report Jim, that no background animation is moving on the secondary monitor. The purple Gorgonia is stationary until MA3 is shown only on the primary screen. The fan coral is also still stationary when viewed only on the secondary screen.
The bottom edge of the background wash when different resolutions are used, is now fixed, and no smearing is visible. But it is still necessary to have both screens at the same resolution or the smaller resolution image is stretched to cover the whole screen, and the images on the two monitors therefore do not then line up.

ie. The secondary monitor is not showing the whole image at a lower resolution, (when one is chosen), it is cropping the second screen's image down to the chosen resolution, and then stretching it across the whole screen. .... Same as was shown in this post.



Because of the above, I have not yet been able to study the fish changes in any detail.

Edit: I've had chance now to study those three fish with the added Specular etc. - It's really nice to watch the shading on the sides of the fish vary as they change direction. Particularly the Copperband! ... Great job, Jim! ... The same three in Beta8 now look quite boring...

[rctneil]

Hey Jim, On my secondary monitor the background object does not animate but is fine on single screen

[Jim Sachs]

Found the non-primary-monitor problem. The vertices were being copied to the other render units, but not the matrices. Try Beta8b.


Someone had mentioned that it looked as though everything was being done separately for each monitor. Well, of course that's exactly the case (and why multimonitors are so hard to implement). Each monitor has its own Render Unit within the program, which includes its own textures, object models, shaders, matrices, and any other device-specific objects and code. So the entire rendering loop has to be executed separately for each monitor. Cards which use system RAM instead of having their own on-board RAM might be faster on multimonitor systems, since they can probably get away with just one copy of the program. Several people have mentioned a slowdown when an MA3 window is partially on each monitor. On my Vista system, which uses shared memory, the program runs at full speed no matter how the window is split.

[cjmaddy]

Part success, - animation on both monitors now in full swing! (Pun untended!) - But only if both monitors are on!
All background animation stationary on secondary, if primary is selected to display nothing.
The different resolutions problem, is still present.

[Rick Simon]

Originally posted by Jim Sachs:

Found the non-primary-monitor problem. The vertices were being copied to the other render units, but not the matrices.  

Still have a small problem with the Purple Gorgonia here on a triple monitor setup. I'm still not getting any movement of it under certain conditions. Here's a list of what I'm seeing:

1) when in windowed mode the Gorgonia has motion regardless of which monitor the window is on.

2) when set to span across all three monitors, the Gorgonia does not have any detectable motion. Though panning is turned on in this mode, there is almost no panning motion either since the width of the screens is almost equal to the width of MA3. I don't know if that has any bearing on this.

3) with the leftmost monitor set to "Display nothing on this monitor" the Gorgonia has proper motion while MA3 is panning back and forth across just the rightmost two monitors.

4) with MA3 set to "Render same image on all monitors", the Gorgonia moves properly on the leftmost two monitors but has no motion on the rightmost one. It is interesting to note though that the Gorgonia does show a correct perspective shift while panning on the rightmost monitor, just no current induced movement ala the sea fans.

[Jim Sachs]

Cliff - I'm not quite sure how to handle that situation. The calculations are all done for the primary monitor, then copied to all the others. It's assumed that if any monitor is on, it would be the primary. But if it is physically possible to run a system without a primary monitor, I guess I'd better figure out how to cover it.

Rick - That's a lot to digest. I'll have to mull it over.

[Rick Simon]

Originally posted by Jim Sachs:

Rick - That's a lot to digest. I'll have to mull it over.  

I wouldn't worry too much about it unless someone else happens to be seeing the same thing. I just did some more checking on things and I'm starting to think it is something pretty specific to my setup. I went into Windows display properties and shifted my monitors around into various configurations. The end result is that there is only one configuration where I have MA3 span across all three monitors and the Gorgonia doesn't move. It's just a sign of my luck that it happens to be the config I normally use.

Nor am I overly worried about it not working with MA3 set to show the same thing on all 3 monitors since that is a config that I would never use anyway.

[Jim Sachs]

Is it always Monitor 3 which lacks the animation? The monitor # is shown in the Statisitcs text, just before "Beta8b". Monitor 3 would be shown as #2, since we start with 0.

[cjmaddy]

Originally posted by Jim Sachs:

Cliff - I'm not quite sure how to handle that situation. The calculations are all done for the primary monitor, then copied to all the others. It's assumed that if any monitor is on, it would be the primary. But if it is physically possible to run a system without a primary monitor, I guess I'd better figure out how to cover it.  

Jim, I'm sorry, I can't help you there. All I can do is compare MA3 to how other similar 3D applications behave that span two or more monitors. As I understand it, only one monitor can ever be the 'Primary', the next one, wherever it is positioned relative to the first, will always be the 'Secondary monitor'.

Rick, - I don't think it's the position of the monitor that will determine what might happen, It's the one that is set to be the 'Primary monitor' that will decide which screen will show movement, and which will show stationary animation. - At least that is how it works on my system. - Any (one, but only one!), of your monitors can be set to be the 'Primary'! - The choice is yours.

[Rick Simon]

Originally posted by Jim Sachs:

Is it always Monitor 3 which lacks the animation? The monitor # is shown in the Statisitcs text, just before "Beta8b". Monitor 3 would be shown as #2, since we start with 0.  

No, it's #1 in your stats text, #2 in Windows. My normal setup is:

http://webpages.charter.net/rlsimon/monitors.jpg

The image shows the monitor stats in the order that they are physically viewed.

[cjmaddy]

Rick, - that #1 is your 'Secondary' monitor. And it is behaving the same as my secondary, - which is what I would expect,

[Jim Sachs]

I guess I need to somehow detect whether the primary monitor is shut down, and if so, to do the calculations on the first monitor I come across which IS turned on.

[cjmaddy]

Yes, but whether it is turned on or not is determined by your MA3 Multimonitor Settings. The card's Display Settings is where the choice of which monitor will be primary is decided, - and that does not change even if you shut a monitor down.

[Jim Sachs]

Ah, if only it was my MA3 Multimonitor Settings. Then I might actually have a glimmer of an idea how it worked. It's a Microsoft thing - That's why those screens look so different. I just link to it, and it's supposed to handle everything else.

[cjmaddy]

Oh!

[Rick Simon]

Originally posted by cjmaddy:

Rick, - that #1 is your 'Secondary' monitor. And it is behaving the same as my secondary, - which is what I would expect,  

Except that if I turn off my tertiary monitor and only run MA3 across 2 monitors, then it works just fine. It is only "broken" if I have MA3 spanning across all three or if I have MA3 set to "Render the same on all monitors".

[cjmaddy]

Reading your posts 299 and 301, our primary and secondary monitors are/were behaving in a similar way. Things improved with 8b, - see my 297 post.

[Rick Simon]

Originally posted by cjmaddy:

Reading your posts 299 and 301, our primary and secondary monitors are/were behaving in a similar way. Things improved with 8b, - see my 297 post.  

To be honest, with the sheer number of possible configurations, I don't tend to pay much attention to "primary" and "secondary" monitor names. It can mean a lot of different things on different systems. For instance, I happen to be running a PCIe Radeon 9550 which happens to be a dual output card and a PCI GeForce FX5200. In this case, the 9550 has "primary" and "secondary" outputs while the FX5200 has only a single output. Since PCIe happens to have the priority on this motherboard, the 9550's primary/secondary naming does happen to hold true. What if the situation was reversed though? What if I were running a PCIe GeForce MX400 which has only a single output and a PCI Radeon 9250 which has dual outputs? Since the MX400 is PCIe it would have priority and be the "primary" monitor for the system. Or perhaps I might be using a system with two video cards that each only support one output. Which one is "primary" and which one is "secondary" under that scenario?

Nor do the fun and games end there. I've run across quite a few motherboards that let you select in the BIOS which type of slot (AGP/PCI for instance) receives priority as the "primary" video output. How does that affect the "primary" and "secondary" display? There are also things like the Matrox Dualhead2Go to further complicate matters a bit. And then there is always the fun of Windows to be tossed into the mix. You can pretty much select any of your displays and assign it as the "primary" as far as Windows is concerned.

All in all, while the "primary" and "secondary" names can be meaningful in situations where you are only dealing with a single video card with dual outputs, or two single output cards where one of them is AGP/PCIe and the other is straight PCI, there are also a lot of other scenarios where it gets a lot murkier. That's why I tend not to pay much attention to those names.

[cjmaddy]

I'm sure Jim will find that a great help.

[Jim Sachs]

Descending into Multimonitor Hell today. Got my flashlight and shotgun. If I'm not back in three days, carry on without me.