In this process, I summarized the iterative ideas of game lighting production based on my own lighting test results and past production experience. The purpose is to provide theoretical reference and iterative ideas for the production of the next chapter of the Little Devil game.
- 1.Fog and ambient light-create a simple game atmosphere
- 2.Reflection Probe- fill light and capture the reflection information of the object
- 3.Direction/ Point/ Spot Light-add light details in the scene
Fog and ambient light
Light and fog do not only provide visual enjoyment, Olafur Eliasson uses his unique artistic approach to use light and fog as a mirror for human thinking. Similarly, the game with artistic properties also need to affect the mood of the player in the fog. Therefore another element of the work of game lighting is the use of fog Ambient. Usually. fog , ambient light and main light can roughly determine the final atmosphere of the game scene. This is very similar to the rapid color laying in painting. In some game development, Ambient light is simply divided into three colors that affect the upper top surface, the sides and the bottom surface of the model. This is an extremely effective and inexpensive method for game production, even for games that strive for extreme graphic effects such as Zelda.
And for Fog. First of all, to explain the real world fog is a condensation of water vapor consisting of small water droplets or ice crystals suspended in the atmosphere near the surface of the earth, is a common weather phenomenon, fog can affect visibility. In virtual reality in general the fog effect is relatively simple to achieve, the so-called fog effect, is in the direction away from our viewpoint, the object looks like it is masked with a certain color (usually gray).
In the traditional fixed pipeline, has been built-in fog effect, simulation of fog concentration calculation there are three algorithms: Linear fog Linear, exponential fog Exponential, second-order exponential fog Exp2. some game production companies in pursuit of immersion, two outside the script language written in height fog and volume fog. As much as possible to restore the physical display. Among them, Linear fog Linear, exponential fog Exponential, second-order exponential fog Exp2 and height fog implementation is based on the superposition of color in the absence of model coverage will not produce the effect of fog, which will make the picture first and not real. And volume fog and special effects fog in supplement and enrich the game screen at the same time can effectively solve the false performance of other fog in the model boundary. Lighting is a very important carrier in the landscape. The combination of volume fog and lighting, especially the combination with colored lights, can form rich colors and bring people a very impactful visual enjoyment.
Reflection probe
When the light stops, the art stops. In the road of artistic exploration reflection as part of light, reflection in the game of creative still has a lot of room for development (Torres, O’Leary, Nicholas & Paulos, 2017) In addition to the light source within the game, reflection effect is an important part of the work of the game lighting engineer, such as water, mirror surface need to reflect the effect of other objects. Usually, the player sees the color of the model = ambient light + direct light + indirect light + basecolor. A small part of the model also includes its own self-illumination. When no reflection probe is used in the scene, objects in the scene with reflections (including Specular and Metallic) use the information from the sky map (including Sky Plane / Sky Box / Sky Dome) to create the reflection effect. In simple scenes, reflections using only sky maps are barely adequate; but in immersive games, such reflections are falsely substandard.
The main use of the light detector is to provide high-quality lighting (including indirectly reflected light) for moving objects in the scene. The second use is to provide lighting information for static landscapes when using Unity’s Level of Detail (LoD) system. For example, in the Genesis project, different areas of the world will have larger Reflection probe boxes, while some Points of Interest will have additional smaller Reflection probe boxes. The purpose of doing so is to optimize the game scene while achieving the desired graphics effect. In some industrial processes, cubemap is often used in conjunction with the Reflection probe. Ambient reflection is a more common method in games. cubemap is a cube map, with six faces corresponding to one map, which is rendered by the camera in each of the six directions, that is, a pre-baked environment map. Usually, a Reflection probe is used to capture the scope of the scene, and then the cubemap is used to bake the game scene.
Lighting system in the engine
In addition to color, the lighting mode and the type of light source is one of the most important parts of the game. Different lighting modes can greatly affect the performance of the game and the atmosphere of the graphics. There are different modes of lighting. These modes are related to the mobility of the lights and the way they are used in the scene. These modes differ in terms of performance, so it is important to consider the lighting modes when implementing lighting. The common lighting modes are baked, blended and real time. Of course the naming of lighting modes varies from game engine to game engine.
In immersive games, the effect of static lighting as well as a mixture of dynamic lighting is usually used. Static lighting is cheaper to run on the device and provides a better experience for the end user of the game. Dynamic lighting, on the other hand, can provide real-time shadows for moving objects, including characters, thus increasing the sense of realism. As for the type of lighting can be broadly divided into: directional light, point light, spot light. where directional light is used as the main light source. point light, spot light can be used as the main light source for some areas. However, the game usually requires the lighting artist to manually add fill light to increase the color level and sense of atmosphere of the scene. This is similar to impressionist painting, usually in the dark areas of the physical color is the most rich, but at the same time to pay attention to good control of brightness.