Render window running slow after upgrade vtk.js from 21.2.1 to 25.6.0

[jilei-hao]

High-level description

The render window started running really slow for a model we built after upgrading the vtk.js version from 21.2.1 to 25.6.0.

I haven't touched the project since January and by then it was running smoothly with version 21.2.1. But after I re-run the project last week, the surface rendering was a little strange and I thought I should upgrade the library, since the browser has been constantly upgraded. My current version of browser is 103.0.5060.134 for intel mac.

I tried loading our model to the vtk.js example scene explore, and was having same performance issues. Our current model is about 8.4MB (zipped 4MB), exported as json scene from the VTK c++ library.
Ovary.zip

Steps to reproduce

Current behavior

• Download the attached scene file that contains the model
• Load the file in the scene explorer example

Environment

• vtk.js: 25.6.0
• OS: macOS Monterey 12.4
• Browser: Chrome 103.0.5060.134 (Official Build) (x86_64)

[floryst]

I'm loading your Ovary.zip file into the SceneExplorer, and I'm not seeing any slow rendering on Apple Silicon. I can try on an Intel machine.

[jilei-hao]

Thanks for testing and replying! I attached two profiles from dev tool to help troubleshooting. "fullsize-slow.json" is generated when I loaded the full-size file in my first post. The "downsampled-fast.json" is generated when I loaded a significantly downsampled file. If you can see the screenshots in the profile, the full size file change position only after a period of time while the downsampled file was moving smoothly.

Let me know if any other information could be helpful for troubleshooting.
Downsampled.zip
profile.zip

[daker]

@jilei-hao please try this solution #2494 (comment) this is a GPU backend issue

[jilei-hao]

@daker The solution works! Thank you so much!