Scene or mesh intermittently flashes to black/invisible

[alexcode9]

Description

Hi, first of all — thanks for the amazing work on this library!
I’ve been testing the included examples, and they render perfectly on my main machine with an NVIDIA RTX 2070 SUPER.
However, on other systems, parts of the scene or individual meshes randomly flash to black or become invisible for a frame or two
No errors or warnings appear in the logs when this happens.

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Logs

✅ Working system (RTX 2070 SUPER)

EGL version in native plugin1.5
Google Inc. (NVIDIA)
ANGLE (NVIDIA, NVIDIA GeForce RTX 2070 SUPER Direct3D11 vs_5_0 ps_5_0, D3D11-32.0.15.8129)
OpenGL ES 3.0.0 (ANGLE 2.1.18844 git hash: 2693b03eba82)
media_kit: FlutterGLTexture: Direct3D Feature Level: 11_1
Created a new texture 1264x681

⚠️ System showing issue (Intel integrated GPU)

EGL version in native plugin1.5
Google Inc. (Intel)
ANGLE (Intel, Intel(R) HD Graphics 530 Direct3D11 vs_5_0 ps_5_0, D3D11-26.20.100.7262)
OpenGL ES 3.0.0 (ANGLE 2.1.18844 git hash: 2693b03eba82)
media_kit: FlutterGLTexture: Direct3D Feature Level: 11_1
Created a new texture 1264x681

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Systems tested

• ✅ NVIDIA RTX 2070 SUPER — all examples render correctly
• ⚠️ Intel integrated GPU (normal PC) — frequent black flashes on meshes or entire scenes
• ⚠️ NVIDIA RTX 4060 (laptop) — same behavior as the Intel GPU

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Video

Examples.Artifacts.mp4

Environment

• Flutter version: latest stable 3.35.7
• Library version: three_js: ^0.2.5
• Platform(s): Windows 11 (Flutter desktop build)
• Examples affected: WebglLightsSpotlight, WebglLoaderGltf

[Knightro63]

HI @alexcode9,

Thanks for letting me know. I will take a look. It might be the type of renderer. I changed it from pixel buffer to texture renderer and this might have a cpu to gpu issue.

[Mariolismo]

Hi! It looks like we might be experiencing the same issue with similar specs.
I’m not sure if this is currently being worked on, but if it isn’t, could you possibly point us toward the offending change? We’d be happy to help out if you can share some hints or insights. Thanks! :D

[Knightro63]

Hi @Mariolismo and @alexcode9,

Sorry I have been busy. I think it is due to the update for linux that had the artifact issue.

In flutter_angle/lib/desktop/angle.dart can you comment out line 717. This might only need to be there for linux. It looks like a glFlush or glFinish is being called at the wrong time.

If this is the case then It might be in the three_js/lib/renderers/web_gl_renderer.dart line 961.

Lastly if everything else is fine then it would be in three_js/lib/others/three_viewer.dart lines 253-254.

Hope this helps.

[alexcode9]

Hey @Knightro63

• Commenting out line 717 has no effect at all
• The _gl.flush(); call obviously has big impact if removed but I’m not sure where to test moving it
• Removing renderer!.clear(); renderer!.setViewport(0, 0, width, height); also has no effect

I’ll keep experimenting, if you have any other tips or get a chance to look into it later, thanks a lot!

[Knightro63]

Hi @alexcode9 ,

I have found the issue is the compatibility with tone mapping and the GPU drivers. There are a couple of things you can try. First is to set the app specific performance to high for whatever graphics card you have. 2 you can remove tone mapping. 3 you can try setting power performance to high for the ThreeJs settings. Below tone mapping.

Hope this helps

[alexcode9]

Thanks a lot for the follow-up and the suggestions!
Removing tone mapping doesn’t seem to do anything, and the powerPreference: three.PowerPreference.high setting also doesn’t appear to have any visible effect.

One thing I noticed specifically on my machine, which might be relevant:
if I disconnect the second monitor and leave only one active, I can consistently reproduce a very similar bug.

Example.Xyvbdudk44.mp4

I also noticed that the issue seems to get worse when I interact with other windows while the app is running, or when I open dialogs/menus from the Windows system tray.

Sharing this in case it helps narrow down the root cause.

Thanks again for the support! 💡

[Knightro63]

Hi @alexcode9,

Lets see if this is an updated flutter_angle issue. Can you change the following in the three_js_core/lib/others/three_viewer.dart file.

      texture = await angle?.createTexture(      
        AngleOptions(
          width: width.toInt(), 
          height: height.toInt(), 
          dpr: _resolution!,
          alpha: settings.alpha,
          antialias: settings.antialias,
          customRenderer: !settings.useSourceTexture,
          useSurfaceProducer: false
        )
      );

If it is this it has to do with how the machine is using the direct3d 11 surface. Putting this to false uses glreadpixels, which is slower but might render correctly.

[alexcode9]

This actually seems to solve the issue, thank you!! 🙌
Performance did take a noticeable hit, though. Interestingly, the FPS counter reports almost the same values (maybe 5–10 FPS lower), but the perceived smoothness is much worse. The scene feels like it’s running at ~30 FPS even when the counter says otherwise. It’s still acceptable on my machine, but definitely slower, so we’ll probably need to look for a better long-term fix.