Bloom and color grading in Unity

Introduction

Bloom and color grading help make game visuals look more vibrant and realistic by adding glow and adjusting colors.

You want to make bright lights in your game glow softly, like sunlight or neon signs.

You want to change the overall mood of a scene by adjusting colors, like making it look warm or cold.

You want to improve the visual quality of your game to make it more appealing.

You want to highlight important objects or areas by making colors pop.

You want to create a cinematic look for cutscenes or gameplay.

Syntax

Unity

using UnityEngine;
using UnityEngine.Rendering;
using UnityEngine.Rendering.Universal;

public class BloomAndColorGradingSetup : MonoBehaviour
{
    public Volume volume;
    private Bloom bloom;
    private ColorAdjustments colorAdjustments;

    void Start()
    {
        if (volume.profile.TryGet<Bloom>(out bloom))
        {
            bloom.intensity.value = 1.5f; // Set bloom glow strength
        }
        if (volume.profile.TryGet<ColorAdjustments>(out colorAdjustments))
        {
            colorAdjustments.saturation.value = 20f; // Increase color saturation
            colorAdjustments.contrast.value = 10f;   // Increase contrast
        }
    }
}

You need to have a Volume component with a profile that includes Bloom and ColorAdjustments effects.

Adjust values like intensity, saturation, and contrast to get the look you want.

Examples

This makes bright areas glow more intensely.

Unity

bloom.intensity.value = 2.0f; // Stronger bloom glow

This reduces color vibrancy, making the scene look more gray.

Unity

colorAdjustments.saturation.value = -30f; // Desaturate colors for a dull look

This shifts colors to warmer tones like orange and red.

Unity

colorAdjustments.temperature.value = 10f; // Warmer color tone

Sample Program

This script sets up bloom and color grading on a volume to add a soft glow and slightly boost colors when the game starts.

Unity

using UnityEngine;
using UnityEngine.Rendering;
using UnityEngine.Rendering.Universal;

public class SimpleBloomColorGrading : MonoBehaviour
{
    public Volume volume;
    private Bloom bloom;
    private ColorAdjustments colorAdjustments;

    void Start()
    {
        if (volume.profile.TryGet<Bloom>(out bloom))
        {
            bloom.intensity.value = 1.2f;
            bloom.threshold.value = 1.0f;
        }
        if (volume.profile.TryGet<ColorAdjustments>(out colorAdjustments))
        {
            colorAdjustments.saturation.value = 15f;
            colorAdjustments.contrast.value = 5f;
        }
    }
}

Important Notes

Make sure your camera uses a Universal Render Pipeline (URP) asset for these effects to work.

You can tweak bloom and color grading settings in the Volume profile in the Unity Editor for quick previews.

Too much bloom or saturation can make the scene look unnatural, so adjust carefully.

Summary

Bloom adds a glowing effect to bright parts of the scene.

Color grading changes the overall colors to set mood or style.

Use Unity's Volume system to control these effects easily.

Practice

1. What does the Bloom effect do in Unity's post-processing?

easy

A. Adds a soft glow to bright areas to make lights look natural

B. Changes the color saturation of the entire scene

C. Sharpens the edges of objects in the scene

D. Removes shadows from the scene

Solution

1. Step 1: Understand Bloom effect purpose

   Bloom adds a glow effect around bright parts of the image to simulate light scattering.

2. Step 2: Compare options to Bloom definition

   Only Adds a soft glow to bright areas to make lights look natural describes adding a soft glow to bright areas, matching Bloom's function.

3. Final Answer:

   Adds a soft glow to bright areas to make lights look natural -> Option A

4. Quick Check:

   Bloom = Soft glow on bright areas [OK]

Hint: Bloom = glow around bright lights, not color changes [OK]

Common Mistakes:

• Confusing Bloom with color grading
• Thinking Bloom sharpens edges
• Assuming Bloom removes shadows

2. Which of the following is the correct way to enable Bloom in a Unity Volume component via script?

easy

A. volume.profile.Enable<Bloom>();

B. volume.profile.TryGet<Bloom>(out Bloom bloom); bloom.active = true;

C. volume.profile.SetActive<Bloom>(true);

D. volume.profile.GetComponent<Bloom>().enabled = true;

Solution

1. Step 1: Recall Unity Volume API for post-processing

   To access and enable Bloom, use TryGet to get the Bloom component and set its active property.

2. Step 2: Analyze each option's syntax

   volume.profile.TryGet<Bloom>(out Bloom bloom); bloom.active = true; uses TryGet and sets bloom.active = true, which is correct. Others use invalid or non-existent methods.

3. Final Answer:

   volume.profile.TryGet<Bloom>(out Bloom bloom); bloom.active = true; -> Option B

4. Quick Check:

   Use TryGet and set active true [OK]

Hint: Use TryGet to access and activate Bloom in Volume profile [OK]

Common Mistakes:

• Using GetComponent instead of TryGet
• Calling non-existent Enable or SetActive methods
• Setting enabled instead of active property

3. Given this code snippet in Unity, what will be the effect on the scene's color grading?

var volume = GetComponent<Volume>();
if (volume.profile.TryGet<ColorAdjustments>(out var colorAdjust)) {
    colorAdjust.saturation.value = -100f;
    colorAdjust.contrast.value = 50f;
}

medium

A. The scene colors become fully desaturated with increased contrast

B. The scene colors become more saturated and less contrasty

C. The scene brightness increases but colors stay the same

D. No change happens because values are invalid

Solution

1. Step 1: Understand colorAdjust properties set

   Saturation is set to -100, which means no color (black and white). Contrast is increased to 50, making differences stronger.

2. Step 2: Predict visual effect on scene

   The scene will look grayscale with stronger contrast between light and dark areas.

3. Final Answer:

   The scene colors become fully desaturated with increased contrast -> Option A

4. Quick Check:

   Saturation -100 + Contrast 50 = grayscale + strong contrast [OK]

Hint: Negative saturation means grayscale; contrast >0 means stronger contrast [OK]

Common Mistakes:

• Thinking negative saturation increases color
• Confusing contrast with brightness
• Assuming no effect from these values

4. You wrote this code to enable Bloom but it doesn't show any effect:

var volume = GetComponent<Volume>();
if (volume.profile.TryGet<Bloom>(out var bloom)) {
    bloom.enabled.value = true;
}

What is the likely problem?

medium

A. You need to set bloom.intensity.value to a positive number

B. TryGet is incorrect; use GetComponent instead

C. Bloom effect must be added to the camera, not the volume

D. You should set bloom.active = true, not bloom.enabled.value

Solution

1. Step 1: Check how Bloom is enabled

   Bloom is enabled by setting bloom.active = true (Bloom has no 'enabled' property).

2. Step 2: Identify missing or wrong property

   The code sets non-existent bloom.enabled.value, so Bloom is not enabled (compile error).

3. Step 3: Understand correct fix

   Use bloom.active = true instead, as stated in You should set bloom.active = true, not bloom.enabled.value. (Also ensure intensity > 0 for visibility.)

4. Final Answer:

   You should set bloom.active = true, not bloom.enabled.value -> Option D

5. Quick Check:

   Bloom uses active, not enabled [OK]

Hint: Use bloom.active = true, not enabled.value [OK]

Common Mistakes:

• Not setting intensity value
• Confusing enabled with active property
• Trying to add bloom to camera instead of volume

5. You want to create a night scene with a blue tint and soft glowing street lights using Unity's Volume system. Which combination of settings achieves this best?

hard

A. Set Color Adjustments temperature to 50, saturation to 50; disable Bloom

B. Set Color Adjustments contrast to 100; enable Bloom with intensity 0

C. Set Color Adjustments temperature to -50, saturation to -20; enable Bloom with intensity 1.5

D. Set Color Adjustments exposure to 5; disable Bloom

Solution

1. Step 1: Choose color adjustments for blue tint and mood

   Lower temperature (negative) adds blue tint; slight desaturation (-20) softens colors for night mood.

2. Step 2: Enable Bloom for glowing street lights

   Bloom intensity 1.5 adds soft glow around bright lights, perfect for street lamps.

3. Step 3: Evaluate other options

   Set Color Adjustments temperature to 50, saturation to 50; disable Bloom warms colors (wrong for night), disables bloom; C sets bloom intensity 0 (no glow); D overexposes scene and disables bloom.

4. Final Answer:

   Set Color Adjustments temperature to -50, saturation to -20; enable Bloom with intensity 1.5 -> Option C

5. Quick Check:

   Blue tint + bloom glow = night scene effect [OK]

Hint: Blue tint = negative temperature; bloom intensity > 0 for glow [OK]

Common Mistakes:

• Using positive temperature for blue tint
• Setting bloom intensity to zero
• Overexposing scene for night effect