Bloom and color grading in Unity - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of this bloom intensity adjustment code?

Consider this Unity C# snippet that adjusts bloom intensity dynamically. What will be the final bloom intensity printed?

Unity

using UnityEngine;
using UnityEngine.Rendering.PostProcessing;

public class BloomTest : MonoBehaviour
{
    public PostProcessVolume volume;
    private Bloom bloomLayer;

    void Start()
    {
        volume.profile.TryGetSettings(out bloomLayer);
        bloomLayer.intensity.value = 1.5f;
        AdjustBloom(2.0f);
        Debug.Log($"Bloom intensity: {bloomLayer.intensity.value}");
    }

    void AdjustBloom(float multiplier)
    {
        bloomLayer.intensity.value *= multiplier;
    }
}

A Bloom intensity: 2.0

B Bloom intensity: 3.0

C Bloom intensity: 1.5

D Bloom intensity: 0

💡 Hint

Think about how the intensity value changes when multiplied by the multiplier.

The initial bloom intensity is set to 1.5. Then it is multiplied by 2.0, resulting in 3.0.

❓ Predict Output

intermediate

What color tint will be applied after this color grading code runs?

Given this Unity C# code snippet that modifies color grading, what will be the final color filter applied?

Unity

using UnityEngine;
using UnityEngine.Rendering.PostProcessing;

public class ColorGradingTest : MonoBehaviour
{
    public PostProcessVolume volume;
    private ColorGrading colorGradingLayer;

    void Start()
    {
        volume.profile.TryGetSettings(out colorGradingLayer);
        colorGradingLayer.colorFilter.value = Color.white;
        ApplyTint(new Color(0.5f, 0.2f, 0.2f));
        Debug.Log($"Color filter: {colorGradingLayer.colorFilter.value}");
    }

    void ApplyTint(Color tint)
    {
        colorGradingLayer.colorFilter.value = tint;
    }
}

A Color filter: RGBA(0, 0, 0, 1)

B Color filter: RGBA(1, 1, 1, 1)

C Color filter: RGBA(0.5, 0.2, 0.2, 1)

D Color filter: RGBA(0.2, 0.5, 0.2, 1)

💡 Hint

The color filter is set directly to the tint color passed.

The color filter is initially white but then set to the tint color (0.5, 0.2, 0.2).

🔧 Debug

advanced

Why does this bloom intensity adjustment code cause a NullReferenceException?

Examine this Unity C# code snippet. Why does it throw a NullReferenceException when run?

Unity

using UnityEngine;
using UnityEngine.Rendering.PostProcessing;

public class BloomBug : MonoBehaviour
{
    public PostProcessVolume volume;
    private Bloom bloomLayer;

    void Start()
    {
        bloomLayer.intensity.value = 2.0f;
    }
}

A bloomLayer is never assigned and is null, so accessing intensity causes NullReferenceException.

B Start method is not called automatically, so bloomLayer is null.

C intensity is not a valid property of bloomLayer, causing NullReferenceException.

D volume is null, so accessing bloomLayer.intensity causes NullReferenceException.

💡 Hint

Check if bloomLayer is assigned before accessing its properties.

bloomLayer is declared but never assigned using TryGetSettings, so it remains null causing the error.

📝 Syntax

advanced

Which option correctly sets the bloom threshold to 1.2 in Unity C#?

Choose the correct code snippet that sets the bloom threshold value to 1.2 using PostProcessing bloom settings.

A bloomLayer.threshold.value = 1.2f;

B bloomLayer.threshold = 1.2f;

C bloomLayer.threshold.SetValue(1.2f);

D bloomLayer.threshold = new FloatParameter(1.2f);

💡 Hint

Remember that bloom threshold is a parameter with a value property.

The threshold is a FloatParameter, so you set its value property directly.

🚀 Application

expert

How many color grading settings are changed after this code runs?

This Unity C# code modifies color grading settings. How many distinct settings are changed after execution?

Unity

using UnityEngine;
using UnityEngine.Rendering.PostProcessing;

public class ColorGradingChange : MonoBehaviour
{
    public PostProcessVolume volume;
    private ColorGrading colorGradingLayer;

    void Start()
    {
        volume.profile.TryGetSettings(out colorGradingLayer);
        colorGradingLayer.saturation.value = -20f;
        colorGradingLayer.contrast.value = 15f;
        colorGradingLayer.colorFilter.value = Color.red;
        colorGradingLayer.saturation.value = -10f;
    }
}

A 1

B 4

C 2

D 3

💡 Hint

Count each unique setting property changed, ignoring repeated changes to the same property.

Saturation, contrast, and colorFilter are changed. Saturation is changed twice but counts as one setting.