## Calculate the extension of a line

Unity Engine
1

Hi everyone,

I like to calculate the extension of line in 3D. Lets say we have p1(x,y,z) and p2(x,y,z).
The distance between p1 and p2 is eg. 10m.

3392670--266759--Untitled-1.jpg
3392670--266759--Untitled-1.jpg771×253 12 KB

Now I want to get the 3D points of C,D,E by a function:
The extension direction should go to the second argument in this case p2
verctor3 = GetLineExtenstionPoint(newDistance, p1, p2)
For sure minus newDistance should give the point between p1 and p2.

And the extension direction should direct to p1 in this case.
verctor3 = GetLineExtenstionPoint(newDistance, p2, p1)

Does anyone know how to?
Thanks a lot!

2

Lerp between them based on the ratio of the current distance and the desired distance… Take the normalized vector and move along it… Few ways to skin that cat.

3

something like this?
var n = vector3.Distance(p1,p2);
var newpos = Vector3.Lerp(p1, p2, n * newDistance);

hmm… I think n must be normalized