Here’s an example of what I had in mind for that. The noise values are uploaded directly to the GPU into a floating point texture instead of being mapped to colors in JavaScript. The shader now does the mapping.
This requires that the user has OES_texture_float support. "OES_texture_float" | Can I use... Support tables for HTML5, CSS3, etc reports 96% coverage across devices so it should be relatively safe to use. If not there are ways to encode floats as RGBA8 textures (clipping planes and elevation band materials are examples of code that does that)