Vector3.Magnitude is incorrect

[ZachCurtis]

Vector3.Magnitude is incorrect

@Kampfkarren I don't get it why Roblox makes bug reporting for the engine such a pain.

[LPGhatguy]

This is an artifact of IEEE floating point numbers and slightly differing implementations. It doesn't really matter and isn't a bug.

You shouldn't try to compare floating point values directly, that's almost never what you want.

[Kampfkarren]

It is out of scope, you'd post this one on the dev forums.

Either way, nobody really needs this degree of accuracy on Roblox, but if you do you can just use your own custom function. It is a bug, but not really one that matters too much.

[ZachCurtis]

Not a dev forum member. Lost quite a bit of time hunting down seemingly causeless math bugs during unit testing; turns out the bugs weren't mine. Thankfully spotted the issue but it required a print() on pretty much every single variable until I noticed it was the Vector3.magnitude call.

Noticed that Color3.toHSV() does this as well:

My toHSV function; final decimal point correctly rounds:
0.16666666666667 0.58823525905609 1
Color3.toHSV, very odd that it rounds earlier and fills in digits after the round with seemingly random numbers:
0.16666667163372 0.58823525905609 1

Roblox's object's methods should cut off the return value at 8 decimal places if a solution to return the correct number is not possible.

@ZachCurtis all of the object methods, such as Instance and Vector3 are part of the C/C++ engine, not the CoreScripts. Report it via email here, or report it on the devforum (or get someone to do it for you)

[Kampfkarren]

@stillunt1tled Dev forum members can not post on behalf of other users, including non-members.

[cliffchapmanrbx]

Hi there, thank you for your feedback. We're going to be closing this repository as we've chosed the Roblox Dev Forum as our venue for developer feedback. Please feel free to migrate your feedback to a DevForum post if you feel it is still relevant.