Floating Health Bars

Questions & Answers
1

I am attempting to create floating health bars for moving game objects. After a fair amount of Googling, I finally found a decent enough example to start with. The example I found uses GUI.DrawTexture with a normal Texture object (not a GUITexture or Texture2D). Here is the relevant code for the script I have attached to my game objects:

public class Creep : MonoBehaviour
{
	public Texture barBG;
	public Texture barFG;
	private Vector3 barPos;
	private float yOffset = 2.2f;
	private float barWidth = 256.0f;
	private float barHeight = 32.0f;
	private float barScale = .25f;
	
	public float maxHealth = 10f;
	public float health;
	private float healthPercent;
	
	private float healthBar;
	private Color highHealth = new Color(7.0f / 255.0f, 161.0f / 255.0f, 7.0f / 255.0f);
	private Color mediumHealth = new Color(161.0f / 255.0f, 157.0f / 255.0f, 7.0f / 255.0f);
	private Color lowHealth = new Color(161.0f / 255.0f, 42.0f / 255.0f, 7.0f / 255.0f);
	private Color barColor;
	
	void Start()
	{
		barWidth *= barScale;
		barHeight *= barScale;
		health = maxHealth;
		healthPercent = health / maxHealth;
	}
	
	void Update()
	{
		barPos = Camera.main.WorldToScreenPoint(new Vector3(transform.position.x, transform.position.y + yOffset, transform.position.z));
		barPos.y = Screen.height - barPos.y;

		healthPercent = health / maxHealth;
		if (healthPercent > 0.50f)
		{
			barColor = Color.Lerp(mediumHealth, highHealth, (healthPercent - 0.50f) / 0.50f); // want 1.00 to be 100%, want .50 to be 0%
		}
		else
		{
			barColor = Color.Lerp(lowHealth, mediumHealth, healthPercent / 0.50f); // want .50 to be 100%, want 0.00 to be 0%
		}
	}
	
	void OnGUI()
	{
		GUI.color = barColor;
		GUI.DrawTexture(new Rect(barPos.x - barWidth/2, barPos.y, barWidth, barHeight), barBG, ScaleMode.StretchToFill, true, 0.0f);
		GUI.DrawTexture(new Rect(barPos.x - barWidth/2, barPos.y, barWidth * healthPercent, barHeight), barFG, ScaleMode.ScaleAndCrop, true, 0.0f);
	}
}

This code does work and it accomplishes most of what I wish to accomplish, but I’m having trouble getting the colors to appear as I would like them to. The colors representing the RGB values I’m using should be bright and vivid. If I create a GUITexture in the game and set the same colors, the green looks like this:
alt text

But in-game, using the same texture file (but not as a GUITexture), it looks like this:
alt text

Is this because I’m using the GUI.color variable? Is there anyway to brighten it to display the intended RGB color value?

Also, if anyone has any recommendations for a better approach to implementing floating health bars, I’d love to hear it. I tried using GUITextures and Texture2D, but didn’t have much luck with them. I’m still new to Unity and its API though, so I would appreciate any advice.

2

Your code is quite good. And yes, because you using GUI.color. But I would change it a little. I think, you have two textures of bar. One as a background (most likely in dark tones), and the second - full filling in the color (if you want change color in compliance with health as gradient, that color must be white). Further, I will write a simple example:

 public Texture2D barBG; //use Texture2D
 public Texture2D barFG;
 ...
 
 void OnGUI() {
  //First draw background of bar
  GUI.color = Color.white; //resset gui color
  GUI.DrawTexture(new Rect(barPos.x - barWidth/2, barPos.y, barWidth, barHeight), barBG, ScaleMode.StretchToFill);
  //Second draw fill bar, but draw in group
  GUI.BeginGroup(new Rect(barPos.x - barWidth/2, barPos.y, barWidth * healthPercent, barHeight));
  //Apply color
  GUI.color = barColor;
  //Draw bar or him part
  GUI.DrawTexture(new Rect(0, 0, barWidth, barHeight), barFG, ScaleMode.StretchToFill);
  GUI.EndGroup();
 }

I hope that it will help you.