Use unit norm when finding plane distanceToPoint

[casawa]

In case the normal supplied is not of unit length.

[WestLangley]

Thanks for checking the code. The more the better!

All normal vectors in three.js are assumed to be of unit length. This is not something we check.

We can add a comment in the Plane docs.

[casawa]

Ah -- is it worth it to maybe call normalize upon initialization? That way, say I want the norm to be in the direction of <0.5, 1, 0>, then as a client I don't necessarily need to always calculate the normalized version and respective constant on my end.

[WestLangley]

is it worth it to maybe call normalize upon initialization?

If we did that, the plane constant would be immediately changed after setting it, which may lead to more confusion.

We assume normals and direction vectors have unit length. It is best to be consistent throughout the library, so users know what to expect.

[casawa]

Makes sense; will try to add a small comment to the Plane docs.

[WestLangley]

Makes sense; will try to add a small comment to the Plane docs.

Yes, please do.