WebGPURenderer: updateRanges are ignored when using instancing.

[AndreyPrakhov]

Description

When using WebGPURenderer({ forceWebGL: true }), partial buffer updates via InstancedBufferAttribute.updateRanges appear to be ignored. Calling attribute.clearUpdateRanges(); attribute.addUpdateRange(start, count); attribute.needsUpdate = true; results in the entire attribute buffer being re-uploaded each frame, instead of the specified range (this is true for both backends)

Reproduction steps

In the test example, the buffer is partially updated with a specified range (this can be toggled in the constants above). However, when checking the profiler, it becomes clear that even with the minimal value, the write time does not decrease.

Code

attr.clearUpdateRanges();                  
attr.addUpdateRange(floatOffset, floats);  
attr.needsUpdate = true;   

Maybe I am doing something wrong?

Live example

https://jsfiddle.net/1krcs5fh/3/

Screenshots

Version

r179.1

Device

Desktop

Browser

Chrome

OS

Linux

[Mugen87]

in WebGPURenderer, InstanceNode manages instanced render objects with internal UBOs or attributes depending on the buffer size. Update ranges are not yet supported in InstanceNode.

Outside of instanced rendering (so when using non-instanced geometry attributes), updated ranges should work as expected.

[AndreyPrakhov]

Is support for update ranges on instanced instanceMatrix attributes planned in WebGPURenderer?

[Mugen87]

My impression is this feature has been overlooked so far. But since it is not uncommon to update just some instances and not all at once, I think update ranges should be supported.