getting object local direction?

Questions & Answers
1

Its been a while since I have tried to script and I cannot figure this out…

I am trying to get the local direction of a parent object so I can add local force to a particle with a script. And I thought that

transform.parent.up

gave you the local direction and it worked in one situation but not in another. It just seemed to use the world direction as the scripting reference says…

So my question is how do I get the local up direction of a object?

Thanks!

2

All the possible direction vectors, not sure if you want a local or global:

using UnityEngine;
using System.Collections;

public class DrawSampleVecs : MonoBehaviour
{
	void OnDrawGizmos()
	{
		Color color;
		color = Color.green;
		// local up
		DrawHelperAtCenter(this.transform.up, color, 2f);
		
		color.g -= 0.5f;
		// global up
		DrawHelperAtCenter(Vector3.up, color, 1f);
		
		color = Color.blue;
		// local forward
		DrawHelperAtCenter(this.transform.forward, color, 2f);
		
		color.b -= 0.5f;
		// global forward
		DrawHelperAtCenter(Vector3.forward, color, 1f);
		
		color = Color.red;
		// local right
		DrawHelperAtCenter(this.transform.right, color, 2f);
		
		color.r -= 0.5f;
		// global right
		DrawHelperAtCenter(Vector3.right, color, 1f);
	}
	
	private void DrawHelperAtCenter(
	     	     	 Vector3 direction, Color color, float scale)
	{
		Gizmos.color = color;
		Vector3 destination = transform.position + direction * scale;
		Gizmos.DrawLine(transform.position, destination);
	}
	
}

Also remember that Transform.eulerAngles can be useful.

direction vecs