From the docs: With regards to updating BufferGeometries, the most important thing to understand is that you cannot resize buffers (this is very costly, basically the equivalent to creating a new geometry). You can however update the content of buffers Let’s say I pre-allocate an array with size…

Resizing is definitely not possible since typed arrays are fixed size. If the array is completely filled, you have to create a new instance (which is expensive). I don’t have performance measurement data to illustrate the respective overhead but it’s a best practice to avoid buffer creation. I don…

Or make a system that has a tradeoff between various performance. Are you going to create mostly up to 1000, but sometimes 1001? create a bigger cache Are you sometimes creating up to 1000, other times up to 5000? either 1 or every time you go over a 1000 increment, make a new geometry Is …

If I have to reallocate the BufferAttribute, do I have to make a completly new geometry, or is there some way to just overwrite the BufferAttribute?

Would it be better if individual BufferAttributes were disposable? A BufferGeometry may have multiple BufferAttributes, and there are cases where we only want to grow one of the BufferAttributes.

IMHO yes, it’d be nice if we could dispose BufferAttributes individually. Probably comes down to cost complexity of implementing it in the renderer, whether or not a pull request for that would be accepted. I’m not sure whether resizing them individually makes sense or not though, probably they sho…

oops, oh, I was thinking uniforms, f.e. accessing data from A based on index of attribute B modulo A length.

How costly is allocating new BufferAttribute array?

Questions

Mugen87 March 26, 2021, 5:14pm 5

If the size of the buffer changes then yes, you have to call dispose() on the geometry and create a new one.

Is it possible to overwrite an InstancedBufferAttribute without creating a new geometry?

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How costly is allocating new BufferAttribute array?

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