# Simple Line Formation

I'm working on the first formation for my game's troops. These should simply stand on land, facing the same direction.

To achieve this, I tried to create offsets towards a pivot-unit, that is approximately the unit in the center of the formation. The units are (temporary) elements of a squad list withing the Squad class. I divide the List by 2 and get the closest integer, that should be the pivot point of the formation. Now I generate offsets for all units on the left side (Unit 1 to pivot-1) and right (pivot+1 to last unit) based on the distance/gaps.

This is the code for the line formation. Sadly, the units are only forming a very stange line with no visually detectable system:

int count = (int)(squadMembers.Count / 2);
center = pivot.transform.position;
switch (type) {
case FormationType.Line:
int space = 5;
for (int i = 0; i < squadMembers.Count; i++) {
int dist = 0;
if (i > count) {
dist = (count + 1) * space;
center.x -= dist;
}
if (i < count) {
dist = (count - 1) * space;
center.x += dist;
}
tmp.StartMove(center);
}
break;
}


It also appears that this only works along the x axis, any idea how i can realize this with the walking/facing direction ov the pivot?

Is there any (obvious) error? How can I improve this script?

PS: Any idea, how I can transform this into a double line (2 Lines behind with half spacing)

• I think some images would help clarify this question. Image of what you have and an image of what you want. – MichaelHouse Mar 1 '17 at 23:52
• @Byte56 Added the current image, I think it's not hard do visualize a straight line in this case, is it? – pguetschow Mar 2 '17 at 6:05

Well I hope I understood your question correctly: you want your squad members at the same distance from one to another, facing the same direction and forming a line.

First I'd tackle the direction issue. Let's say there is a point in world called destination they are aiming to. You may want to create a Vector3 describing the difference between destination and the position of the first member. This will give you the orientation to be aligned to. Once you got that you just have to normalize this vector and multiply it by the distance you want between squad members. This will give you an offset to apply from a member to another. So... adding this offset to the first member position will give you the second member position... and so on.

Once the alignement is not a problem anymore, making your unit members look in the same direction (means, looking at destination point), you can simply use LookAt method on their Transform.

Something like this (edited to use the pivot):

public class Aligned : MonoBehaviour
{
[SerializeField]
private List<Transform> units;
[SerializeField]
private GameObject destination;
[SerializeField]
private float distance = 5;

private void Start()
{
// Find the ID of the pivot
// ie: unit at the center of the line / list
int pivot_id = units.Count / 2;
Transform pivot = units[pivot_id];
// Make the pivot look at the destination and save the rotation
pivot.LookAt(destination.transform);
Quaternion look_rot = pivot.rotation;

// Create the offset between units
Vector3 offset = pivot.position - destination.transform.position;
offset = offset.normalized * distance;
for (int i = 0; i < units.Count; ++i)
{
// Apply position offset
units[i].position = pivot.position + offset * (i - pivot_id);
// Make the unit look at the destination point
units[i].rotation = look_rot;
}
}
}

• Thanks for the reply; this is relatively close to my first attempt, when the lines was ordered from left to right, but in this cas I'm struggeling with the correct offset if I want to form the line based on a unit in the middle – pguetschow Mar 2 '17 at 10:04
• Edit: They,re also standing nearly always infront of the pivot unit, instead next to it. – pguetschow Mar 2 '17 at 10:25
• The offset would be the exact same based on the unit in the middle. Just use position - offset*unit_count/2.0f on the first unit only and it'll do the trick. – lvictorino Mar 2 '17 at 12:41
• Edit: I'm not sure to understand what the pivot unit is for you :S – lvictorino Mar 2 '17 at 12:41
• Jup, did changed that already, was on the train while writing this^^ Pivot unit is the unit in the centre everything is relative to within the formation. – pguetschow Mar 2 '17 at 12:59