MeshPhysicalMaterial attenuationDistance is null when exporting to JSON

[davcri]

Describe the bug

const mesh = new THREE.Mesh(new THREE.BoxGeometry(), new THREE.MeshPhysicalMaterial())
console.log(mesh.material.attenuationDistance); // Infinity (correct)
const json = JSON.stringify(mesh.toJSON())
const x = new THREE.ObjectLoader().parse(JSON.parse(json))
console.log(x.material.attenuationDistance); // null, but it should be Infinity

Live example

• https://jsfiddle.net/we3c562t/5/ (open the console)

Expected behavior

Serializing and deserializing should preserve the material appearance.

Probably we should avoid exporting attenuationDistance when it's equal to Infinity (the default value).

Related issue: #24622

Screenshots

I noticed this issue by exporting and re-importing a MeshPhysicalMaterial from the editor.

Attenuation distance is NaN after importing model.json with MeshPhysicalMaterial (with transmission = 1, roughness ~=0)

Platform:

• Device: Desktop, Mobile
• OS: Windows, MacOS, Linux, Android, iOS
• Browser: Chrome, Firefox, Safari, Edge
• Three.js version: dev