This is for a 3D project. The goal is to place an object on a line at the closest point to another line starting at the main camera’s position which goes in the direction of the main camera’s forward vector. I have 2 empty GameObjects marking the start and end positions of a line. How can I find the closest position on that line to the line which passes through the main camera?
Assuming I’m understanding you right, you want to find the shortest line that can be drawn that connects a point on one line to a point on another.
I would say the most efficient way is likely to do a kind of binary search, which is a sort of controlled bruteforce. What I mean by that is that assuming you have a start and end point for both lines, you can split both lines in half and then do a check for the shortest distance between the 4 midpoints (using Vector3.distance). So say you have Line A and Line B, you would find that these 2 halves are closest together:
⠀
⠀
You then Discard the halves that were furthest, moving the start and end point to the new location, and repeat the process:
⠀
⠀
You repeat this 10, 20 or however many times until you believe you have a small enough range that the player can’t possibly get more precise (Say, within 0.001 of the actual shortest positions). A Limitation of a 2D diagram is that the shortest line above will always be at the ends unless they intersect, but in 3D space, it’s the same principle, just get a pair of segments small enough and draw a line between their midpoint.
As for the actual implementation, you can get a point a certain percent along a line using something like
public Vector3 GetPointPercent(Vector3 startPoint,Vector3 endPoint, float percent)
{
return startPoint + (percent * (endPoint-startPoint));
}
Where percent is a decimal between 0 and 1, so 0.1 would give you a point 10% along a line.
Without knowing exactly how your code works I think that’s all the help I can give you, let me know if you have any further questions.