Lighting theory of 3D games: formal lighting design method, with lighting as the depth

Lighting intended for a specific purpose is called task lighting, as opposed to merely cosmetic or decorative illumination. My thinking is it’s NOT about setting a rigid binary of which lights are exactly what, but rather it’s to get you to envision what specific tasks a specific light enables you to do. Many lights can be both functional and decorative — for example, a candle flickering to a restaurant dining table is moodily dim and intimate, but it also can help you discern different tables and see your food.
In games, we are concerned with making the entire world readable (or selectively unreadable) for the player, to help them navigate and wayfind via a space, in addition to discern different game items. We also want to reassure the player that the world was constructed with some sort of intent, and that they are not wasting their time and/or money. For the time being, let us try considering light more formally. How does light let’s read a game more readily, and exactly what are a few common patterns? In 3D games, light provides us key depth cues and permits us to read the surface of the object.
Sometimes this flatness is a fantastic thing that may simplify our scenes and make them easier to see, or sometimes we will want to trick the player, but a lot of the time that is a distraction that prevents a participant from knowing what they’re watching and interacting with your match — and because we’re attempting to portray a 3D object on a flat 2D display, we frequently want all the depth cues we can get.

3D games


In”fullbright”, or whenever a game engine leaves models unlit at default 100% brightness, so it is difficult to tell the difference between the cylinder and the sphere. To assist read 3D depth into a 2D image, we need to use feel, fog, similar things near us and far from us — we need spatial context. Lighting is the principal instrument for creating this context. With light, we can read the contour and a mesh’s surface normals — the direction(s) a specified 3D surface is perceptible, while it’s concave / convex, round or flat, etc..
Reading this surface topology is often very significant for playing 3D games. Is this hill too steep to climb, am I supposed to proceed here? Just how much is it to the top or underside of the room, can I jump up or fall down safely? A lot of this type of lighting is all about signposting for the player to help them understand their environment.
The picture above is a scene from Residue Processing in Half-Life 1. Notice the hanging ceiling spotlights focus on the ground, leaving the walls relatively dim — this helps highlight the neon green splashes in the poisonous sludge, which is an important threat during this chapter. It also builds visual hierarchy; the bottom of the space is a great deal more important than the top of the room. (One criticism: the concealed light strips along the ceiling edges are lazy and thoughtless, and do not feel industrial to me personally. If they desired to isolate the metal ceiling in the concrete shell, then they should’ve used geometry to do that. And there’s already a cut! As it stands, it’s just a mainly horizontal plane split for no reason.)
On the left, the depart out of this room is lit sensibly, so we understand where we are going and do not linger for a long time. (The NPC also shoots the headcrab monsters and runs out that exit. Valve really wanted you to follow.) The simplest way to light a space would be to light every crucial game thing / affordance, and make sure the player can observe where they want to go. If something isn’t important, then don’t bother light it.

Lighting intended for a specific purpose is called task lighting, as opposed to merely cosmetic or decorative illumination. My thinking is it’s NOT about setting a rigid binary of which lights are exactly what, but rather it’s to get you to envision what specific tasks a specific light enables you to do. Many lights can be both functional and decorative — for example, a candle flickering to a restaurant dining table is moodily dim and intimate, but it also can help you discern different tables and see your food.
In games, we are concerned with making the entire world readable (or selectively unreadable) for the player, to help them navigate and wayfind via a space, in addition to discern different game items. We also want to reassure the player that the world was constructed with some sort of intent, and that they are not wasting their time and/or money. For the time being, let us try considering light more formally. How does light let’s read a game more readily, and exactly what are a few common patterns? In 3D games, light provides us key depth cues and permits us to read the surface of the object.
Sometimes this flatness is a fantastic thing that may simplify our scenes and make them easier to see, or sometimes we will want to trick the player, but a lot of the time that is a distraction that prevents a participant from knowing what they’re watching and interacting with your match — and because we’re attempting to portray a 3D object on a flat 2D display, we frequently want all the depth cues we can get.
In”fullbright”, or whenever a game engine leaves models unlit at default 100% brightness, so it is difficult to tell the difference between the cylinder and the sphere. To assist read 3D depth into a 2D image, we need to use feel, fog, similar things near us and far from us — we need spatial context. Lighting is the principal instrument for creating this context. With light, we can read the contour and a mesh’s surface normals — the direction(s) a specified 3D surface is perceptible, while it’s concave / convex, round or flat, etc..
Reading this surface topology is often very significant for playing 3D games. Is this hill too steep to climb, am I supposed to proceed here? Just how much is it to the top or underside of the room, can I jump up or fall down safely? A lot of this type of lighting is all about signposting for the player to help them understand their environment.
The picture above is a scene from Residue Processing in Half-Life 1. Notice the hanging ceiling spotlights focus on the ground, leaving the walls relatively dim — this helps highlight the neon green splashes in the poisonous sludge, which is an important threat during this chapter. It also builds visual hierarchy; the bottom of the space is a great deal more important than the top of the room. (One criticism: the concealed light strips along the ceiling edges are lazy and thoughtless, and do not feel industrial to me personally. If they desired to isolate the metal ceiling in the concrete shell, then they should’ve used geometry to do that. And there’s already a cut! As it stands, it’s just a mainly horizontal plane split for no reason.)
On the left, the depart out of this room is lit sensibly, so we understand where we are going and do not linger for a long time. (The NPC also shoots the headcrab monsters and runs out that exit. Valve really wanted you to follow.) The simplest way to light a space would be to light every crucial game thing / affordance, and make sure the player can observe where they want to go. If something isn’t important, then don’t bother light it.