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Judder issues with Vive Focus


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I don't quite understand what is going on. I've tried to post this message several times on this sub-forum and it keeps getting deleted. Perhaps I posted this message to the wrong place? If so, let me know. It does not appear that my message has been moved, but instead, it appears as though my post was simply deleted. I am using Vive Wave SDK, and using the Vive Focus, and I have a legitimate question.


Over the past week I've been experimenting with the Vive Focus.


I've been experimenting with various versions of my app. I've stripped the app down to its most essential elements.


However, I face a significant problem which I cannot solve. There appears to be a significant judder when I pan my head from side to side if I try to attempt anything of significant complexity within my scene.


I have tested various versions of various scenes by eliminated everything from the scene except one model.

Using the profiler I see nothing unusual and everything is well within the suggested limits outlined in the case study provided by 2 Bears Studio on every scene I experiment with.


Simple, unanimated 3D objects such as the default Unity 3D models seem to work well.


If I try to deploy more complex objects which show on Unity's game view to be anywhere from 5k to 10k tris, I begin to experience judder if I pan my head from side to side.


If I am connected to the PC trying while the profiler is on the judder appears to be worse.


Animating an object make the judder worse.


Moving my head faster makes the judder worse.


If I am not connected to the PC and viewing simpler objects which are not animated the judder appears to disappear.


Any ideas?


Here are the specifications of the various software tools I'm using:


Developer Kit Vive Focus Updated to 1.92.1400.2

Wave SDK Version is 2.1.8

Unity Version 2018.1.9f1 Personal

Vive Input Utility v.1.10.2


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Yes unfortunately many titles on the store suffer from judder.  Not sure if internally they are running at 60fps and as screen is forced at 75hz, it causes issues
Would also be nice if it would be possible to have a 60hz mode as videos at 30/60fps look absolutely horrible with judder non-stop due to the displays 75hz and video update at 60hz.   Its fine when moving head around as the changes seem rendered at 75hz, but the actual frame rate changes at 60hz do not match the display refresh
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Thank you for your reply.


Ok. So is this something I can adjust in Unity to mitigate the issue?


If not, is there a per object limit or something that you might suggest I shoot for in terms of complexity whether it's polygons or materials/shaders?


I noticed after replaying a lot of the free apps and games that every app experiences some judder to a greater or lesser extent.

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This judder which is more apparant when objects are more complex can unfortunately merely be due to the system/drivers not optimised well on the vive focus.  The extra pixels and refresh rate would also result in 35% more pixel throughput compared to a oculus go (2560x1440) at 60hz - although the snapdragon 835 soc on the focus should scale up well to this.  
Even though the profiler may be calculating that there is ample cpu/gpu resources for your scene, there may be this other bottleneck in the system that is causing it to use more resources than it should perhaps? (Again perhaps related to the system drivers)
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More data:


The judder becomes noticeable at 500 to 1000 tris on a single mesh, with or without animation.


I will see it judder a tiny bit when viewing a mesh with 150 tris.


I put a little FPS monitoring code into the app to display FPS on a canvas as I use the Vive Focus.


In every case, no matter which mesh I'm using, my frames per second hovers consistently at just under 75, usually around 74.8, and, again, this is on the Vive Focus.

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