isVector3 is present when serializing Vector3

Describe the bug

A clear and concise description of what the bug is. Before submitting, please remove unnecessary sections.

since r141, when serializing Vector3 class using JSON.stringify, isVector3 is present

To Reproduce

Steps to reproduce the behavior:

1. Go to ‘…’
2. Click on ‘…’
3. See error

Code

// r141
console.log(new THREE.Vector3())
// output:
// {isVector3: true, x: 0, y: 0, z: 0}

// r140
console.log(new THREE.Vector3())
// output:
// {x: 0, y: 0, z: 0}

Live example

*141

*140 Expected behavior

Should not contains isVector3 ( also, I don’t think it is a good idea to have a boolean inside an heavily use class memory wise )

Screenshots

Platform:

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

[donmccurdy]

I’m worried that this thread seems pretty far down a very niche path… THREE.Vector3 does not need to be optimized around storing millions of Vector3 instances in memory — that’s a terrible choice for performance regardless of this particular boolean property. This is the reason why three.js (and GPU APIs) have moved toward typed-array-based APIs like BufferAttribute instead. If you need to iterate over many vertices, a small number of vectors should be pooled and initialized, when needed, from compact binary views.

Let’s keep .is properties please, they’re fine. 🙏

[olivierchatry]

Well, never mind, we did something really stupid ( I removed the simplifyRadialDist from the typedarray buffer test … ). I guess I’m not blown away anymore !

For science:

With simplifyRadialDist on both test ( vec3, typedarray ):

❯ node bench.js
arrayWrite 2600.320638999983 milliseconds.
vec3Write 3766.281397999992 milliseconds.
three.js/src/math on  dev [?⇣] with  took 6s
❯ node bench.js
arrayWrite 2905.3484539999918 milliseconds.
vec3Write 4216.024967000005 milliseconds.
three.js/src/math on  dev [?⇣] with  took 7s

Without simplifyRadialDist on both test ( vec3, typedarray ):

❯ node bench.js
arrayWrite 4425.489473998547 milliseconds.
vec3Write 5163.734323002398 milliseconds.
three.js/src/math on  dev [?⇣] with  took 9s
❯ node bench.js
arrayWrite 4212.7496079951525 milliseconds.
vec3Write 5430.644314996898 milliseconds.
three.js/src/math on  dev [?⇣] with  took 9s

We were comparing vec3 with simplifyRadialDist against typedarray without. Not really a fair fight. At least I now have peace of mind on that because I was really disturb when we tried.