Use freezeActiveMeshes as soon as possible

[Janx]

Hi,

I have trouble with the mesh selection phase, which takes too long and therefor causes frame rates around 30 FPS. My scene contains roughly 2000 meshes, most of them empty (just used as containers or transformations). I do not know, if that is considered too much. Anyhow, using freezeActiveMeshes (thanks for adding this) to disable the mesh selection phase solves my problem, because the actual rendering of the scene is quite fast, even with all meshes activated. I therefore want to unfreezeActiveMeshes whenever the scene was changed and to freezeActiveMeshes as soon as possible. I thought using the onAfterActiveMeshesEvaluationObservable was a good idea to get informed when the mesh selection phase is completed, but using freezeActiveMeshes in the callback causes the engine to stall completely. You can see this here: https://playground.babylonjs.com/indexStable.html#0WHH9Q#5 Disabe the callback and it works: https://playground.babylonjs.com/indexStable.html#0WHH9Q#6

What is going on? Am I misusing the onAfterActiveMeshesEvaluationObservable?

Cheers,
jan

[Gijs]

Hi, from the error in the console it seems that freezeActiveMeshes causes onAfterActiveMeshesEvaluationObservable to be called, and creating an infinite loop. But regarding the meshes, can't you use a TransformNode instead?

[trevordev]

To replace onAfterActiveMeshesEvaluationObservable for your scenario you could have a flag that states if a new mesh has been created and use scene.on(Before/After)RenderObservable to check if a freeze is needed.

[Guest]

I also recommend to use TransformNode as much as you can for containers as they are not processed by the evaluation phase hence reducing its cost

[Janx]

Awesome, thanks for the quick support! @Gijs @Deltakosh I was not aware of Transformation Nodes and will start using them right away. @trevordev Thanks for the idea. Looking at the code of freezeActiveMeshes it is absolutely correct, that it notifies the onAfterActiveMeshesEvaluationObservable again. So I came up with a check in the callback whether freeze was already requested: https://playground.babylonjs.com/indexStable.html#0WHH9Q#7 I like this approach a bit more, since than again calling unfreeze is enough to update the scene.