Docs/Lighting

Day/Night Cycles

Create dynamic day and night cycles with sun movement and color transitions.

18 min read Intermediate Updated 2026-07-01 v2.0 ~59 min to complete

Introduction

Day/night cycles add immersion and gameplay variety. This guide covers sun movement, sky color transitions, star fields, and nighttime lighting.

Guide 7 of 25

This is part of the Intermediate Guides collection. Category: Lighting. Estimated completion: 59 minutes. Difficulty: Intermediate.

Screenshot

Step-by-Step Guide

Create a time system

Add a TimeManager object. Track time as 0-24 (hours). Set time speed (1 in-game hour = 2.5 real minutes).

Animate the sun

Rotate the directional light based on time. 6:00 = sunrise (east), 12:00 = overhead, 18:00 = sunset (west).

Transition sky colors

Lerp sky colors: dawn (orange), day (blue), dusk (red-orange), night (dark blue). Use gradient presets.

Add stars at night

Show a starfield between 20:00 and 5:00. Fade stars in/out smoothly at twilight transitions.

Adjust ambient light

Day ambient bright (0.4), night ambient dim (0.05) with blue tint. Moonlight provides minimal directional light.

Trigger gameplay events

Use time-based events: enemies spawn at night, shops open during day, certain NPCs appear at specific times.

FluxScript Example

Here is a complete FluxScript implementation for this guide:

Day/Night Cycles — FluxScript

timeOfDay = 8.0
timeSpeed = 0.1

const SKY = {
  dawn:  { light: 0.8 },
  day:   { light: 1.2 },
  dusk:  { light: 0.6 },
  night: { light: 0.1 }
}

on update(dt) {
  timeOfDay += timeSpeed * dt
  if timeOfDay >= 24 timeOfDay -= 24
  sunAngle = (timeOfDay / 24) * 360 - 90
  sun = scene.find("SunLight")
  sun.setRotation(sunAngle, 30, 0)
  phase = getSkyPhase(timeOfDay)
  sun.setIntensity(phase.light)
  stars = scene.find("StarField")
  stars.setOpacity(getStarVisibility(timeOfDay))
  if timeOfDay > 20 || timeOfDay < 6 {
    if !nightSpawned { spawnNightEnemies(); nightSpawned = true }
  } else { nightSpawned = false }
}

func getSkyPhase(t) {
  if t > 5 && t < 8 return SKY.dawn
  if t >= 8 && t < 17 return SKY.day
  if t >= 17 && t < 20 return SKY.dusk
  return SKY.night
}

Node Graph Example

Prefer visual programming? Here is the equivalent Node Graph:

Day/Night Cycles — Node Graph

[On Update] --> [timeOfDay += timeSpeed * dt] --> [Wrap at 24]
   --> [Set Sun Rotation + Intensity]
   --> [Get Sky Phase] --> [Set Sky Colors]
   --> [Set Star Opacity]
   --> [Branch: night time] --> [Spawn Night Enemies]

Optimization Tips

Keep your implementation fast and efficient with these optimization tips:

Bake stars into a skybox texture instead of using particle stars. A textured skybox is essentially free.
Limit real-time light changes. Gradually lerping sun intensity is fine, but changing shadow quality dynamically causes hitches.
Use gradient textures for sky color transitions. Sampling a 1D gradient is cheaper than branching in shaders.
Slow down time speed during gameplay-critical moments. A 4-minute day cycle is too fast for combat-heavy games.