1. Lecture 3 Richard Gesick
GUI Ch 2
Lecture 3
Richard Gesick

2. objectives Both 2D and 3D GUI elements How to create GUI buttons
How to create a 2D health bar
Tracking the player's level by using a GUI label
Using two GUI boxes to make an experience bar
Creating a 3D health bar
Showing 3D damage reports
Showing enemy name tags

3. 2D List<Rect> SkillButtons = new List<Rect>();
List<Rect> ItemButtons = new List<Rect>();
SkillButtons.Add(new Rect(Screen.width/2 + 50, Screen.height/ , 55, 55));
SkillButtons.Add(new Rect(Screen.width/ , Screen.height/ , 55, 55));
ItemButtons.Add(new Rect(Screen.width/ , Screen.height/ , 55, 55));
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4. OnGUI() method GUI.Button(SkillButtons[0], "Skill A");
GUI.Button(SkillButtons[1], "Skill B");
GUI.Button(ItemButtons[0], "Item A");
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5. A health bar with a GUI box
public float currentHP = 100;
public float maxHP = 100;
public float currentBarLength;
public float maxBarLength = 100;
. . .
currentBarLength = currentHP * maxBarLength / maxHP;
GUI.Box(new Rect(Screen.width/2 - 20, Screen.height/ , currentBarLength, 25f), "");
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6. 3D
txtColor = DamageReport.color;
txtColor.a = 0; // 0 transparent, 1 fully opague …
HealthBar.transform.LookAt(Camera.main.transform);
DamageReport.text = Damage.ToString();
txtColor.a = 1;
HealthBar.transform.localScale = Vector3.Lerp(OrigScale, new Vector3(currentBarLength, OrigScale.y,OrigScale.z), Time.fixedTime);
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7. Assignments
Rather than assign the 3D gui to the object, assign to a global object, i.e. the camera.
To maintain visibility, in update use: HealthBar.transform.LookAt(Camera.main.transform);
NameTag.transform.LookAt (new Vector3(-Camera.main.transform.position.x, -Camera.main.transform.position.y, -Camera.main.transform.position.z));
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8. bullets
Prefab bullet
GameObject instantiatedProjectile= Instantiate(bullet, new Vector3(transform.position.x, transform.position.y + 1,
transform.position.z + 1),
transform.rotation) as GameObject;
//Or make a shot spawn position
Destroy(instantiatedProjectile, 2f);
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9. collisions OnTriggerEnter(Collider col)
OnCollisionEnter(Collision col)
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