anisotropy

Butterfly animation.
Tested on Oculus Go (with touchpad) and VR BOX2 (with joystick). For tests on a desktop (Windows 10 + Chrome) the "inline" webxr session and A,S,D,W,↑,↓ keys for navigation are used.
Set "anisotropy" before "Enter WebXR". EXT_texture_filter_anisotropic extension and gl.LINEAR_MIPMAP_LINEAR texture filtering mode are used. Butterfly Function (x2 - y2) sin(x + y)/(x2 + y2) is used for prosedural textures. It is "rotated" by x = (u + v)/2, y = (u - v)/2 transformation as 2uv sin(u)/(u2 + v2).
WebXR samples     updated 11 Apr 2020