Lighting in Unreal Project 1 due · crit

Mon 2:00 · Brief Faking the bounce

Real light bounces infinitely and for free in the physical world. In a game running at 60fps, every bounce costs — so you learn when to let Unreal solve the bounce live and when to precompute it.

Lumen: dynamic global illumination

Direct light is easy: a lamp hits a surface. The expensive part is indirect light — the way a red wall throws pink onto the white floor beside it. Unreal's Lumen solves that bounce in real time, so lights, geometry, and materials can all change and the GI follows instantly — no bake, no lightmap UVs to wait on. It also drives real-time Lumen Reflections, so shiny surfaces reflect the actual scene as it moves. This is the default in a new UE 5.8 project, and for most game scenes it's where you start.

Lightmass: baked lighting when you want it

Sometimes you want lighting precomputed and locked — a mobile target, a fixed hero shot, a scene where every last millisecond of GPU matters. Lightmass bakes indirect light into lightmaps for static geometry: it costs nothing at runtime but can't move. Most projects pick one path per level — fully dynamic with Lumen, or baked with Lightmass — rather than fighting both at once. Know both so you can choose with intent.

Reflections, sky, and lots of lights

Even with Lumen, Reflection Capture actors give you cheap, cached reflections in enclosed spaces, and a Sky Light feeds ambient color from your sky or cubemap so nothing sits in dead black. And when a scene wants dozens or hundreds of shadow-casting lights — a neon alley, a control room of glowing panels — Megalights, production-ready in UE 5.8, makes many dynamic lights affordable that used to be a hard budget wall.

Post-processing is the final grade

Raw engine output is linear and flat. A Post Process Volume applies effects across the whole camera: exposure sets how bright the scene reads; tone mapping maps the wide range of scene values into what the screen can show without blowing out; bloom bleeds light from bright sources; color grading sets your final mood — cool and clinical, or warm and worn. This is the difference between "correct" and "cinematic."

Mon 2:45 · Guided lab Light one scene, well

Key light to reflections to post — the full lighting pass on your assembled kit.

1. Set the key

   Add a Directional Light as your sun/key. Angle it low and off-axis — never flat-on. Set a Rect or Spot Light for fill and a rim from behind. This is three-point lighting, borrowed from film and just as true in a game.

2. Confirm Lumen is on

   In Project Settings → Rendering, verify Dynamic Global Illumination and Reflections are set to Lumen. Now your bounce is live — move the key light and watch the indirect color follow instantly across the kit.

3. Add a Sky Light

   Drop a Sky Light so ambient light and sky color fill the shadows. Set it to real-time capture so it updates with your scene. Nothing should sit in dead black unless you meant it to.

4. Place Reflection Captures

   Add a Sphere Reflection Capture (or Box, for a room) centered in the space and press Build → Build Reflection Captures. Your metallic and glossy surfaces now get accurate cached reflections layered under Lumen's live ones.

5. Push the light count with Megalights

   If your mood wants many small shadow-casting lights — panel glows, string lights, a neon strip — enable Megalights and place them freely. Watch stat unit as you add: Megalights keeps the cost sane where a naïve pile of dynamic lights would tank the frame.

6. Build the Post Process Volume

   Add a Post Process Volume, set it to Infinite Extent (Unbound), and enable overrides: Exposure, Bloom, and Color Grading. Unreal tone-maps by default; now grade for mood.

7. Shape the mood

   Pull the lighting toward one clear feeling with 2–3 primary lights — dawn, interrogation room, neon alley. Kill any light that isn't earning its place. Contrast reads; even brightness reads as nothing.

8. Final pass and frame

   If you chose the baked path, run Build → Build Lighting Only with Lightmass at final quality; if you're fully dynamic, just set a hero Cine Camera angle. Check performance with stat unit and stat gpu. Lighting that looks great but tanks the frame rate isn't done.

Wed 2:00 · Workbench Practice, unhurried

No new material. You work on your own file while I circulate — this is the hour where the technique from the guided lab stops being something you watched and becomes something you can do.

1. Finish the lab on your own work

   The guided lab was built on the class example. Now do it on the piece you are actually submitting. That second pass is where it sticks.

2. If you fell behind, catch up here

   This is what the hour is for. Say so and I will come to you — do not spend it quietly stuck.

3. If you are ahead, go deeper

   Take the optional extensions from the lab, or push the piece further than the brief asks. Nothing graded depends on them.

4. Ask Gary, the AI TA, anything

   The tutor on the course site is open all term for questions about how and why. It explains; you build. No agents in the work until Week 9.

Wed 3:10 · Crit / share Project 1 — Game-Ready Asset Kit

Project 1 is due. Present your kit assembled and lit in one level: we look at silhouette and topology, UV and texture honesty, and now the lighting that ties it together. Have your budget sheet open — triangle counts, texture resolutions, material count — because we check whether the kit is actually game-ready, not just pretty in one frozen frame. Come ready to name one decision you'd change and one you'd defend.

Homework — due before Week 06

Resources

• Lumen global illumination & reflections — Unreal's fully dynamic GI and reflection system.
• UE 5.8 release notes — Megalights production-ready, and what's new in the renderer.
• Unreal Engine documentation — Post Process Volumes, Reflection Capture, Sky Light, and Lightmass baking.
• Unreal Engine — the engine, feature overviews, and free learning paths for lighting in real time.