VDMX fullscreen lag

[larsjessen]

We are using Syphon to get Unity3D graphics into VDMX. It works great when the output in VDMX is windowed there is no lag at all, but as soon as we go fullscreen in VDMX we get a noticeable lag. Has anyone had similar experiences and is there something we can do about it?

Also, we get black borders around the output. I have tried different output settings but I can’t rid of them. Any suggestions are welcome.

[bangnoise]

Are you doing this on a machine with multiple graphics cards, and is the fullscreen display connected to a different card than the one you’re running windowed on? Or, more generally, what is your hardware setup..?

Do you see the black borders in Simple Client ( http://syphon.v002.info/#Apps ) or only VDMX?

[larsjessen]

I am working on one of the new MacBook Pros with two graphics cards: a Radeon HD 6750M and the intel, but I am using the Radeon. For testing I have just tried to run it full screen on the laptop display (but for the final setup I will have a projector connected as the primary monitor to run the full screen).

I don’t see the black boarder in the Simple Client – only in VDMX.

[bangnoise]

The border sounds like the canvas dimensions in VDMX don’t match the Syphon layer’s dimensions – check that?

What are the dimensions of the scene you’re sending from Unity? If you send a similarly dimensioned scene from another app (eg Simple Server or QC) do you get the same slowdown going fullscreen?

[vade]

This could also be an issue simply with :

a) Fill Rate – you may be drawing way too much. GPUs can only fill so many triangles per second. Both Unity and VDMX can easily swamp a GPU with draw calls and fill rate issues on their own. Going full screen 100% effects fill rate, as you are painting a larger portion of the screen.

b) VRam – you may be using more VRam and hitting swap. VRam in OS X is virtual, so you can allocate textures all day long, but once you get over a hardware limit, you will use software (main memory) and things will drastically slow down. Going full screen changes back buffer sizes which, if you are near VRam max, can push you over the edge to swap land.

You can check for both with OpenGL Driver monitor. Look for your video memory and see if it gets too high. For fill rate, I think its “GPU core” usage, but CPU wait for GPU is also a good indicator of rendering latency.

Does changing the unity scene to something simpler make a difference? Does VDMX with a single movie the same size, no effects, one layer, cause the issue? Basically I am curious if you are abusing your system, or if this is a genuine weird issue. Not saying there is not an issue, but this info will help us trouble shoot the issue.

[Brian Chasalow]

I am curious about this being a Unity programmer and and having just myself toured with VDMX for the past several months, esp regarding performance-testing on the new macbook pros.

One thing I would try if i were you: test to see if the unity application itself is lagging itself when you fullscreen VDMX. Try to fullscreen vdmx on an external monitor, and watch the Unity application (hopefully a somewhat basic scene) itself on another monitor. if the unity application appears to lag, remove the syphon server script in unity, rebuild, and test again. I’m curious to see if unity’s ‘run in background’ support is not quite 100%, aside from any Syphon-specific issues.

[larsjessen]

Thank you for the suggestions. I have done some more testing today, and I can’t seem to reproduce the lag that I was experiencing the other day. Now it works just as well fullscreen as non fullscreen. Maybe it was because I had more processes running…

I am still having problems with the black borders when I go fullscreen. I have tried to match the canvas resolution with the unity app resolution with the actual full screen resolution of the screen, but without any luck. It also seems like the graphics are scaled up, so I get quite a grainy image when I go full screen. I wonder if there are some settings in the Quartz Composer syphon plugin that I should tweak?

[vade]

Syphon will output and the native resolution of VDMX, pixel for pixel. Have you set your VDMX preferences, or layer sizes appropriately?

[bangnoise]

Where does the Quartz Composer plugin come in? VDMX has native Syphon support, there’s no need for QC. I’d try filing a bug report from within VDMX and include the project file. Vidvox are usually very helpful and may be able to spot the problem faster than our guessing 🙂

[Brian Chasalow]

Just as confirmation- the Unity plugin is indeed setup to serve using the app’s resolution, so if for instance you start your Unity app at 1024 x 768 in a window, set everything in VDMX to that and go from there.

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