Material properties in Unity - Mini Project: Build & Apply

Material properties

📖 Scenario: You are creating a simple Unity scene where you want to change the color and shininess of a material on a 3D object.

🎯 Goal: Learn how to access and modify material properties like color and shininess in Unity using C# scripts.

📋 What You'll Learn

Create a material variable in a script

Set the material color to red

Set the material shininess to 0.5

Print the material color and shininess values

💡 Why This Matters

🌍 Real World

Changing material properties is common in game development to create different looks and effects on 3D objects.

💼 Career

Understanding how to manipulate materials programmatically is important for Unity developers working on visual design and interactive environments.

1

Create a material variable

Create a public variable called myMaterial of type Material inside a class called MaterialChanger.

Unity

using UnityEngine;

public class MaterialChanger : MonoBehaviour
{
    // Your code here
}

Hint

Use public Material myMaterial; inside the class.

2

Set material color and shininess

Inside the Start() method of MaterialChanger, set myMaterial.color to Color.red and set myMaterial.SetFloat("_Glossiness", 0.5f) to change shininess.

Unity

using UnityEngine;

public class MaterialChanger : MonoBehaviour
{
    public Material myMaterial;

    void Start()
    {
        // Your code here
    }
}

Hint

Use myMaterial.color = Color.red; and myMaterial.SetFloat("_Glossiness", 0.5f); inside Start().

3

Print material color and shininess

Still inside the Start() method, add two Debug.Log statements to print myMaterial.color and myMaterial.GetFloat("_Glossiness").

Unity

using UnityEngine;

public class MaterialChanger : MonoBehaviour
{
    public Material myMaterial;

    void Start()
    {
        myMaterial.color = Color.red;
        myMaterial.SetFloat("_Glossiness", 0.5f);
        // Your code here
    }
}

Hint

Use Debug.Log to print the color and shininess values.

4

Run and check output

Run the Unity scene and observe the Console output showing the material color and shininess values.

Unity

using UnityEngine;

public class MaterialChanger : MonoBehaviour
{
    public Material myMaterial;

    void Start()
    {
        myMaterial.color = Color.red;
        myMaterial.SetFloat("_Glossiness", 0.5f);
        Debug.Log("Color: " + myMaterial.color);
        Debug.Log("Shininess: " + myMaterial.GetFloat("_Glossiness"));
    }
}

// Run the scene and check the Console output

Hint

Open the Unity Console window to see the printed color and shininess values.

Practice

1. What does renderer.material.color control in Unity?

easy

A. The position of the object

B. The color of the object's material

C. The texture applied to the object

D. The size of the object

Solution

1. Step 1: Understand the property name

   The property color inside renderer.material refers to the color attribute of the material.

2. Step 2: Relate to object appearance

   Changing this property changes how the object looks in terms of color, not texture, position, or size.

3. Final Answer:

   The color of the object's material -> Option B

4. Quick Check:

   renderer.material.color changes color [OK]

Hint: Color property changes object color, not texture or size [OK]

Common Mistakes:

• Confusing color with texture
• Thinking it changes object position
• Assuming it changes object scale

2. Which of the following is the correct way to set a material's color to red in Unity C#?

easy

A. renderer.material.color = Color.red;

B. renderer.material.color = "red";

C. renderer.material.color = new Color(255, 0, 0);

D. renderer.material.color = Color(1, 0, 0);

Solution

1. Step 1: Check Unity color assignment syntax

   Unity uses predefined colors like Color.red or new Color(float r, float g, float b) with values between 0 and 1.

2. Step 2: Evaluate each option

   renderer.material.color = Color.red; uses Color.red correctly. renderer.material.color = "red"; uses a string which is invalid. renderer.material.color = new Color(255, 0, 0); uses integers 255 which is incorrect for Color. renderer.material.color = Color(1, 0, 0); misses new keyword and uses wrong syntax.

3. Final Answer:

   renderer.material.color = Color.red; -> Option A

4. Quick Check:

   Use Color.red constant for red color [OK]

Hint: Use Color.red constant, not strings or 255 values [OK]

Common Mistakes:

• Using string "red" instead of Color.red
• Using 255 instead of 1 for color values
• Missing 'new' keyword for Color constructor

3. What will be the output color of the object after running this code?

renderer.material.color = new Color(0.5f, 0.2f, 0.7f);

medium

A. Bright green

B. Black

C. Pure red

D. A shade of purple

Solution

1. Step 1: Understand the Color constructor values

   The values represent red=0.5, green=0.2, blue=0.7 on a scale from 0 to 1.

2. Step 2: Interpret the color mix

   Red and blue are medium to high, green is low, so the color will be a purple shade (mix of red and blue).

3. Final Answer:

   A shade of purple -> Option D

4. Quick Check:

   Color(0.5,0.2,0.7) = purple shade [OK]

Hint: Red + Blue mix with low green = purple shade [OK]

Common Mistakes:

• Assuming values are 0-255 instead of 0-1
• Confusing color channels order
• Thinking low green means green color

4. Identify the error in this Unity C# code snippet that tries to change material shininess:

renderer.material.shininess = 0.8f;

medium

A. Material does not have a 'shininess' property directly accessible

B. The value 0.8f is out of range

C. Missing semicolon at the end

D. Should use renderer.material.color instead

Solution

1. Step 1: Check if 'shininess' is a direct property

   Unity's standard material does not have a direct 'shininess' property; shininess is controlled via shader properties like '_Glossiness'.

2. Step 2: Correct way to set shininess

   You must use renderer.material.SetFloat("_Glossiness", 0.8f); to change shininess.

3. Final Answer:

   Material does not have a 'shininess' property directly accessible -> Option A

4. Quick Check:

   Use SetFloat for shininess, no direct property [OK]

Hint: Use SetFloat("_Glossiness", value) for shininess [OK]

Common Mistakes:

• Trying to access non-existent 'shininess' property
• Confusing shininess with color
• Ignoring shader property naming

5. You want to change the texture of a material at runtime in Unity. Which code snippet correctly does this assuming you have a Texture variable named newTexture?

hard

A. renderer.material.SetColor("_MainTex", newTexture);

B. renderer.material.color = newTexture;

C. renderer.material.mainTexture = newTexture;

D. renderer.material.texture = newTexture;

Solution

1. Step 1: Identify the correct property for texture

   The main texture of a material is accessed via mainTexture property.

2. Step 2: Check each option's validity

   renderer.material.mainTexture = newTexture; correctly assigns newTexture to mainTexture. renderer.material.color = newTexture; wrongly assigns texture to color. renderer.material.SetColor("_MainTex", newTexture); uses SetColor with a texture which is invalid. renderer.material.texture = newTexture; uses a non-existent 'texture' property.

3. Final Answer:

   renderer.material.mainTexture = newTexture; -> Option C

4. Quick Check:

   Use mainTexture to set material texture [OK]

Hint: Use mainTexture property to change textures [OK]

Common Mistakes:

• Assigning texture to color property
• Using SetColor instead of SetTexture
• Using wrong property name 'texture'