Performance on some android devices

[mbalajee]

When rendering a large model (~7K individual renderables) on a mid range devices (2 to 3 years old) the performance has been degraded to the point it becomes unusable.

Affected devices:
Samsung S6 Tab (2019)
Samsung A9+ tab (2023)
Samsung S22 Ultra (2022) - Surprised to see low performance on this device
OnePlus 6T (2018)

Have no problem on Pixel 8 & 7. Even models with over 10K renderables perform smoothly without any dynamic resolution option.

Recording of a model with 7K renderables on Samsung S6 Tab (same result on all affected devices, worst on OnePlus) in the sample gltf viewer (modified dynamic resolution settings)

Screen_recording_20240809_062749.mp4

ModelView initialization,
NOTE: On Pixel 8/7 I don't have to increase the memory configs, even larger models render just fine with the default config which makes me wonder if Filament increases the memory config (such as commandBufferSize) based on GPU ?

 private val modelViewer: ModelViewer = ModelViewer(
     surfaceView = surfaceView,
     manipulator = cameraManipulator,
     engine = Engine.Builder().config(
         Engine.Config().apply {
             // Remember to change the configs in release/config file
             commandBufferSizeMB = 34 * 3 // to keep it 3 times larger than minCommand as per doc
             perRenderPassArenaSizeMB = 32 + 2 // keep it roughly 1MB larger per doc
             minCommandBufferSizeMB = 32
             perFrameCommandsSizeMB = 32
             driverHandleArenaSizeMB = 40
         }
     ).build()
 )

Dynamic resolution settings,

 private fun disablePostProcessing() {
     modelViewer.view.run {
        // I initially disabled post processing following the suggestion from https://github.com/google/filament/discussions/4965
        // but dynamicResolution is also part of post processing and wouldn't work if post processing is disabled.  So I disabled all set...Enabled functions in View class (only two as of now)
         // isPostProcessingEnabled = false
         setShadowingEnabled(false)
         setScreenSpaceRefractionEnabled(false)

         // on mobile, better use lower quality color buffer
         renderQuality = renderQuality.apply {
             hdrColorBuffer = View.QualityLevel.LOW
         }

         // dynamic resolution often helps a lot
         dynamicResolutionOptions = dynamicResolutionOptions.apply {
             enabled = true
             quality = View.QualityLevel.LOW
             minScale = 0.1f
             maxScale = 0.8f
             sharpness = 0.5f
         }
     }
 }

On Web we use XeoKit which also uses something like dynamicResolution. In addition to lowering the quality it doesn't render renderables that are far from camera & almost not visible, when interacting with the model and renders everything once we stop interacting. Is there anything else I can do to improve performance? Am not a graphics developer so sorry if my questions are silly 🙏 how about enabling face culling during the time of interaction or render only the entities that the camera can see (are these happening by default already ?)