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I have a strange problem which has been bugging me for quite a while now, the issue is best explained by a short video:

Video

As you can see the objects in the scene have a jitter when you move the camera around but also a similar thing happens every now and then when the camera is not moving. It's been driving me crazy for a while now. This video has been taken on a Tinkerboard with TinkerOS, but the same issue is also there on a Tinkerboard with FlintOS.

On a regular laptop there is no issue and everything is moving smoothly. I'm not sure if this is a bug or if it is expected behaviour seeing the differences in hardware, so I was hoping somebody could shed some light on this.

Here is a WebGL report from the Tinkerboard: enter image description here

Here a WebGL report from my laptop: enter image description here

Obviously there are differences but I have no idea if any of these difference would explain this behaviour.

Can anyone clarify?

Thanks!

Evertvdw
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  • How big is your white plane, and what are the near and far values on your camera? – pailhead Nov 21 '18 at 20:37
  • I found that when I give the white plane some z-height it does not jitter anymore. There is however still some jitter here and there. My near and far values of the camera are 200 and 4000, I already experimented with that. – Evertvdw Nov 28 '18 at 10:03
  • Is it possible to share a reproducer? It's hard to give specific advice without knowing exactly what you are doing. – solidpixel Dec 02 '18 at 09:36

1 Answers1

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The most likely issue is precision; most mobile GPUs map mediump variables in shaders to FP16 data types, most desktop GPUs map them FP32 data types.

What are your shaders here? Try using "highp" everywhere you compute positions.

solidpixel
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  • I initialized my WebGLRenderer with the option: 'precision: highp'. Are there any other places I can specify this? – Evertvdw Nov 28 '18 at 10:04
  • Start your vertex shader with "precision highp float;", although I think your setting will do that anyway. – solidpixel Dec 02 '18 at 09:35