I can’t find an official answer of document for this, although many asked this question before, boss’s answer always mentions camera.onViewMatrixChangedObservable or scene.onPointerObservable, or You can use scene.render() anywhere you want. But… camera.onViewMatrixChangedObservable.add( () => sce…

I think you can remove the manual call to camera.update() and pass true as the first parameter to render: https://www.babylonjs-playground.com/#UNB24W#11

Thanks for your help, but your demo ( https://www.babylonjs-playground.com/#UNB24W#3 ) still render every frame: [image] You can insert a console to the camera.onViewMatrixChangedObservable, it will continuously print. Luckily, thanks to your hint, I found a perfect way to do this, just replace ca…

How about this: https://www.babylonjs-playground.com/#UNB24W#5 , it works perfectly for me.

And in my real case (with many meshes), I found it can improve perfomance dramatically to replace scene.render() with scene.render(false) for avoiding duplicated camera updating (because camera has been updated by render loop). See: https://www.babylonjs-playground.com/#UNB24W#6

Although camera’s calculation is needed in render loop, but quite a big step. :+1:

Is there any way to keep the smooth camera movement while rendering on demand?

You can do something like that: https://www.babylonjs-playground.com/#UNB24W#7

Thanks, @Evgeni_Popov ! That‘s better. Do you have an idea why it slows down faster than with normal render loop? https://www.babylonjs-playground.com/#UNB24W#8 EDIT: Setting the parameters for scene.render() seems to fix that problem: scene.render(false, true): https://www.babylonjs-playground.c…

Hi, nice thread! The example by @Evgeni_Popov is done with the ArcRotateCamera. Any chance to do it with other cameras such as FreeCamera, too? FreeCamera does not seem to expose an inertia value.

nice, thanks a lot! :slight_smile:

What is the correct way to render on demand

Questions

Evgeni_Popov July 15, 2021, 1:45pm 25

It seems you can test cameraDirection and cameraRotation:
https://www.babylonjs-playground.com/#UNB24W#13

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What is the correct way to render on demand

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