Emissive Materials 自發光材質
Whilst Area Lights are not supported by Precomputed Realtime GI, similar soft lighting effects are still possible using ‘Emissive Materials.’ Like Area Lights, emissive materials emit light across their surface area. They contribute to bounced light in your scene and associated properties such as color and intensity can be changed during gameplay.
盡管預計算實時GI不支持區域燈光，但使用“發光材料”仍可實現類似的柔和燈光效果。與區域燈光一樣，發光材料在其表面區域發光。它們有助於場景中的反射光線，並可在游戲過程中更改顏色和強度等相關屬性。
‘Emission’ is a property of the Standard Shader which allows static objects in our scene to emit light. By default the value of ‘Emission’ is set to zero. This means no light will be emitted by objects assigned materials using the Standard Shader. The HDR color picker can be used to select colors with intensities beyond the 0-1 range in order to create bright light effects similar to those of Area Lights.
'發射'是標准着色器的一個屬性，它允許我們場景中的靜態物體發光。默認情況下'發射'的值被設置為零。這意味着使用標准着色器的物體指定材料不會發射光。 HDR顏色選擇器可用於選擇強度超過0-1范圍的顏色，以創建類似於區域燈光的明亮燈光效果。
There is no range value for emissive materials but light emitted will again falloff at a quadratic rate. Emission will only be received by objects marked as ‘Static’ or “Lightmap Static’ from the Inspector. Similarly, emissive materials applied to non-static, or dynamic geometry such as characters will not contribute to scene lighting.
自發光材質沒有范圍值，但發射的光線會以二次方速率再次下降。自發光只能由inspector面包標記為“靜態”或“光照貼圖靜態”的對象接收。同樣，應用於非靜態或動態幾何體（如角色）的自發光材質也不會影響場景照明。
However, materials with an emission above zero will still appear to glow brightly on-screen even if they are not contributing to scene lighting. This effect can also be produced by selecting ‘None’ from the Standard Shader’s ‘Global Illumination’ Inspector property. Self-illuminating materials like these are a useful way to create effects such as neons or other visible light sources.
然而，即使沒有對現場照明作出貢獻，零輻照度以上的材質仍然會在屏幕上亮起。這種效果也可以通過從標准着色器的“‘Global Illumination(全局照明)”Inspector面板屬性中選擇“None無”來產生。像這些自發光材質是制作諸如霓虹燈或其他可見光源的效果的有用方式。
Simple neon sign created using the ‘Emission’ property of Unity’s Standard Shader. Notice how the emission from the sign is still shadowed by static geometry - in this case, the sphere.
使用Unity標准着色器的“Emission（輻射）”屬性創建簡單的霓虹燈。 請注意，在這種情況下標志的自發光仍然使靜態幾何體的球體產生陰影。
Emissive materials only directly affect static geometry in your scene. If you need dynamic, or non-static geometry - such as characters, to pick up light from emissive materials, Light Probes must be used. Changing emission values at gameplay will update Light Probes interactively and the results will be visible on any objects presently receiving light from those probes.
自發光材質僅直接影響場景中的靜態幾何體。 如果您需要動態或非靜態幾何體（如字符）來接受自發光材質的光，則必須使用Light Probes（光照探針）。 在游戲中更改輻照值將交互式更新光照探針，結果將作用於受到這些探針作用的任何對象上。