MeshPhysicalMaterial: Fixed anisotropy zero strength.

[elalish]

Fixes #26694

Description

@WestLangley You were 100% right - it was just the divide by zero. I'm used to NaNs propogating into completely black pixels, but I guess it must have gotten caught and clamped somewhere else in the shader. But indeed, the problem was only when anisotropy was zero exactly.

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

Filesize dev	Filesize PR	Diff
656.6 kB (162.7 kB)	656.7 kB (162.7 kB)	+96 B

🌳 Bundle size after tree-shaking

Minimal build including a renderer, camera, empty scene, and dependencies.

Filesize dev	Filesize PR	Diff
449.1 kB (108.6 kB)	449.2 kB (108.6 kB)	+96 B

[LeviPesin]

Was the ssl change intentional here? /ping @elalish

[elalish]

Yes, I swear there was a discussion around it somewhere, but I can't find it now. This makes it so you can serve the examples locally over HTTP without having a bunch of angry browser errors. We couldn't find anything this broke - have you?

[hybridherbst]

Juuust was hunting down this issue. All of the WebXR samples break if the files aren't served via HTTPS locally anymore.
One option is to have two separate commands (one with, one without SSL) for "people who don't want to see a HTTPS warning" vs. "people who want to use HTTPS".