Rotate vector to local space

[Pugsworth]

I'm trying to figure out how to rotate a vector so that the 'z' is aligned to the 'z' of the local space.

I'm pretty bad at vector math, so I have no idea where to go.

[editline]a[/editline]

It's a little hard to properly convey exactly what I want.

I want to modify two axes of the vector, but leave the last one intact, but this has to work at any angle.

[Vegasx]

You can use Vector.x, Vector.y, Vector.z to handle specific vector section-y thingies, just an FYI.
So Vector(50,50,500).z should return 500. I don't use this often so I'm not totally sure how it works.

But if you multiply a Vector by Vector(1,1,0), it should preserve the X and Y while setting the Z to 0

Or am I completely missing what you're asking?

[Pandaman09]

[url]http://wiki.garrysmod.com/page/Global/LocalToWorld[/url]
[url]http://wiki.garrysmod.com/page/Global/WorldToLocal[/url]

Are you talking about this?

[Whiterabbit]

I'm pretty sure you need to use [URL="http://wiki.garrysmod.com/page/Angle/RotateAroundAxis"]RotateAroundAxis[/URL] for this, however I've never managed to understand that function works correctly, I just play with the numbers until it magically just works.

[URL="http://maurits.tv/data/garrysmod/wiki/wiki.garrysmod.com/indexc074.html"]Old wiki example[/URL]

[Pugsworth]

I'll try to explain it further.

I have a grid and I want to snap the x and y axes of the grid, but I want to leave the z, or the normal, the same. Because the grid can be at any angle, I don't know how to do this.

[Luni]

[QUOTE=vexx21322;42472435]I'll try to explain it further.

I have a grid and I want to snap the x and y axes of the grid, but I want to leave the z, or the normal, the same. Because the grid can be at any angle, I don't know how to do this.[/QUOTE]

if your vectors are position vectors above/below a grid and you want to snap x and y to the grid, just round off x and y components of the vector and leave the z alone

although I have a sneaking suspicion that may not be what you're looking for because if by "rotating" you mean actually rotating the vector and keeping its magnitude intact, i have no idea what you're trying to do

[Pugsworth]

I can't just change the x and y directly because the grid could be 1, 0, 0 or 0, 0, 1 or even 0.4, 0.1, -0.22 or some shit. This is why I believe I need to do something to change it locally.

Basically, I need the grid to always touch the vector it's at.

[QUOTE=Luni;42472532]if your vectors are position vectors above/below a grid and you want to snap x and y to the grid, just round off x and y components of the vector and leave the z alone

although I have a sneaking suspicion that may not be what you're looking for because if by "rotating" you mean actually rotating the vector and keeping its magnitude intact, i have no idea what you're trying to do[/QUOTE]
I want to snap the grid itself.