Lighting and Rendering-Self-luminous Materials

At present, using the self-luminous road signs has become an international trend, not only in Europe and the United States, but also in Hong Kong and other places in China. Because it not only facilitates identification of all traffic participants, but also effectively reduces the incidence of accidents. The cost of such high-tech street signs is about double that of conventional street signs. So, what's so good about self-luminous street signs? It is said that in the past, road signs made of retro-reflective materials were commonly used in China. Such road signs must be projected by external light sources to be seen clearly. If non-motor vehicles and pedestrians do not have a light source, they cannot see the street signs. Sometimes, the road is dim, and the car needs to turn on the high beam to see the road signs. However, the sudden high beam is very easy to cause a traffic accident.

 

In addition, the has always been the "killer" of the highway. The sudden occurrence of fog cannot be predicted by the meteorological department, and the traffic management department cannot prevent it. Freeway road signs that can actively recognize visibility and automatically dimming can well "show their skills" in the fog and guide vehicles to drive along the road. All this products may use the self-luminous materials. Next we mainly introduce self-luminous materials.

 

 

Although the area light source is not supported by Precomputed Realtime GI, it can still produce a soft lighting effect by using self-luminous materials. Just like area lights, self-luminous materials emit light from their surface area. They can add emitted light to your scene and related attributes such as color and light intensity can be changed while the game is running.

 

‘Emission’ is a property field of the Standard Shader, which allows static objects in our scene to emit light. The value of the 'Emission' attribute field is set to 0 by default. This means that objects that use the Standard Shader material will not glow.

 

The self-luminous material does not have a range attribute, but the light emitted from the material will decay at a quadratic speed. The self-luminous material will only act on objects marked with "Static" or "LightmapStatic" tags. Similarly, if the light-emitting material attaching to a non-static object or a dynamic object like a character has no effect.

However, as long as the emission value is greater than 0, even if they do not receive the scene light source, there will be a glow effect on the screen. This effect can also be changed by changing "Global Illumination" under the emission attribute to "None", like this self-luminous material, it is very suitable for simulating similar light sources such as neon lights.

 

Glow materials only affect static objects in the scene. If you want to affect dynamic objects like characters, you must use Light Probes to pick up lighting information from self-luminous materials and change the emission value when the game runs.

 

Now self-luminous material is widely used in self-luminous products such as self-luminous light, it is an inorganic light storage material, knowing more about the material can help us to make suitable luminous products for our life.