Model.setParameters() triggers program relinking when parameters object alternates between empty and non-empty

[kahole]

While profiling the particle layer, I noticed continuous shader relinking (gl.getProgramParameter, etc) every frame.

After investigation, seems the cause is calling

weatherlayers-gl/src/deck/layers/particle-layer/particle-line-layer.ts

Lines 226 to 230 in 2d49140

	model.setParameters({
	...model.parameters,
	cullMode: 'front', // enable culling to avoid rendering on both sides of the globe; front-face culling because it seems deck.gl uses a wrong winding order and setting frontFace: 'cw' throws "GL_INVALID_ENUM: Enum 0x0000 is currently not supported."
	...this.props.parameters,
	});

inside draw().

This leads to deck.gl's rendering loop, which also calls model.setParameters with the layer parameters, to recreate the render pipeline for the model back and forth constantly.

If you set the parameters on the layer itself to exactly match the ones inside particle-line-layer.ts, the issue goes away. Since the equality check prevents re-creation of the render pipeline.

      new WeatherLayers.ParticleLayer({
        ...
        parameters: {
          depthCompare: 'always',
          cullMode: 'front',
        },

[kahole]

I'm also reporting a bug to deck-gl on use of model.setParameters in render passes. Which seem to suffer some of the same issues when switching between picking and non-picking render passes. Perhaps this unintended behavior and might be a luma.gl bug. Will update here when I know more

[kahole]

So it looks like in Deck.gl 9 the design is to recreate pipelines and shaders when such params change, but rely on caching to make it inexpensive. However, by default caching of shaders and pipelines are turned off. Controlled by device settings _cachePipelines and _cacheShaders. (I have reported this in the deckgl community.)

This makes this issue in the ParticleLineLayer a costly one for performance. I think either way we shouldn't be doing setParameters() in draw(), as these parameters should be passed from the layer. And the layer is constantly prepping a pipeline without these parameters with the current setup, before it's intercepted by this call.

[zakjan]

Hi, thanks for the report, was this with deck.gl 9.2? I see this is expected to be resolved by visgl/deck.gl#9863

[kahole]

Yes, this is basically only a proper issue on deck-gl 9.2, I didn't realize the cache issue wasn't present in 9.1
I do believe there are still some potential drawbacks to setting parameters in the draw call, also on deckgl 9.1, as this leads to model.setParameters being called twice during layer draw, going through the hashing and cache check for switching back and forth between the pipelines, nothing close to the issue having the cache turned off though :D

[zakjan]

Thanks for the hints, the suggested changes are applied in 463593a and released as 2025.11.0, together with deck.gl 9.2 upgrade.