Large memory consumption, why?

[mattes3]

Large memory consumption, why?

[IceCreamYou]

This doesn't really seem like a THREE.Terrain question - I expect you'd have similar results if you created a scene with the same objects without this library. In general, three.js geometry objects can get pretty big. What's in memory is not just the screen buffer, it's all the references to faces, points, etc. that are required to calculate the scene. Browser dev tools have built in profilers these days that you could use to see which objects take up the most memory.

One thing worth noting is that THREE.Terrain might temporarily increase memory usage when applying certain transformations to the plane, as it needs to copy some things in order to do certain calculations, but references to those objects aren't kept and so the allocated memory should be garbage collected within a few seconds.

[mattes3]

In the meantime, I have been analyzing other options for building terrain because the memory consumption was killing my app.

I found out that I can build the terrain on the GPU instead of the CPU. As an example, I built a 4096x4096 terrain using only a heightmap of 64MB in size (4 bytes per texel in GPU framebuffer memory, not in CPU memory). Not a single triangle in sight ... it takes only a 10th of a second to build (once, only), and later in the animation loop, the terrain looks really good! These GPUs are sooooo fast, several teraflops of performance, amazing!

The approach looks so promising that I think I will turn away from using ThreeJS and terrain geometry at all. Success, however, will really depend on how texture mapping, lighting, and shadows will work out with this "no geometry" approach. Will keep you updated.