Week 04: Baked lighting

We will use baked lighting to create an interior scene, to create a very realistic result. (Student example below)

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Blockout

We can start building a room with BSP’s or basic geometry (like in the Ruins assignment).

BSP’s are getting a bit outdated. They are more useful when you are thinking about Level/Game design. Also, they are good for using tiling textures.

IMPORTANT: Make sure that your scale is correct, otherwise you will need you very high/very low values for your lights.

Lighting

Once you have a blockout, we can put in our light(s). 1) First things first, LOCK YOUR EXPOSURE. (As in the previous assignment) Then, make sure that you are working with Global Illumination set to ‘None’. (We aren’t working with Lumen)

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2) We can do our first light bake, and you will notice that our shadows look very jagged. The way to fix this is to up the lightmap resolution of your meshes.

TIP: For BSP’s you need to lower the number, to get a higher lightmap resolution.

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3) Next to the resolution, you can make your shadows softer by changing the source angle in the ‘Lightmass’ tab. Use this one when working with static lights.

KEEP IN MIND: You are by default in Preview rendering mode for your lighting. → Change this to Production for your final lighting.

4) For the interior scene try to use as less lights as possible. You want realistic looking lighting. (Nice ambient lighting, directional light as an accent light for ex.) Rect lights are very good for interior scenes. You have a lot of control over them. (They also have nice soft shadows 🙂 ) Skylights on the other hand, they are better for outdoor/big scenes. Better use rect lights to get nice ambient lighting into your scene. You can still use a skylight, to be able to use an HDRI.

If you see weird artefacts on your mesh, check if the mesh has lightmap UV’s.

Reflections

For reflections you will need to use reflection captures. (box or sphere, boxes are better for rooms 😉) You can add a sun, sky atmosphere and height fog to contribute to your reflections.

Color Grading

Don’t skip this part, this is the cherry on top. Use Curves, LUT’s, Color Balance, Hue/Saturation, Camera Distortion, a tiny bit of Chromatic Abberation, add a bit of grain, etc.. (Bottom image is color graded.)

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Tips

Realism lies in the little details (small bumps, small imperfections, etc.).

Your ambient light needs to be on point.

BSP’s don’t support raytracing. → convert them to static meshes.

You can enable ‘Raytracing Reflections’ in your Post Process Volume.

You can work with Realtime lighting in the beginning, and switch to static later.

Look up how sphere/box reflection captures work.

Turn off/down the intensity of the AO in your Post Process Volume.

Look on the DAE site, Artstation, etc.. to get inspired (OR take a photograph yourself 😉)

Use volumetric lightmaps for foliage, trees, etc.. → Otherwise you will have long baking times.

If you get the warning: “Video memory usage exhausted” → This is propably because Nanite is enabled TO FIX: Go to project settings → Search Nanite → Tick off “Support Nanite” Restart Unreal Type in into Console Command: r.Nanite 0