灯光设置

参考

面板: Properties ‣ Light Shader Editor ‣ Sidebar ‣ Options

把灯光添加到世界环境或者任何带有自发光着色器(自发光材质不能直接照亮场景)的物体上，能直接照亮场景。不同之处是灯光在渲染图像中是不可见的，而且更容易作为自己类型的对象进行管理。

通用选项

所有渲染器的灯光设置。

Eevee

镜面反射

Specular Light intensity multiplier. Use it for artistic control. Defines the intensity with which the light object will be visible in reflections on the surface of specular objects, like metals or mirrors. Setting this to 0 will make the light object disappear from specular reflections. Keep it exactly at 1.0 for photo-realistic results.

自定义距离

If enabled, uses Distance as the custom attenuation distance instead of global Light Threshold. In order to avoid long setup times, this distance is first computed automatically based on a light threshold. The distance is computed at the light origin and using the inverse square falloff.

距离: 指定光线强度衰减到零的距离。

阴影

常用参数

裁剪起点: Distance from the light object at which the shadow map starts. Any object which is closer to the light than Clip Start will not cast shadows. Clip Start is only available for point, spot and area lights.
偏移: Bias applied to the depth test to reduce self-shadowing artifacts. This determines, what size of surface details (for example, bumps) will cast shadows on the object itself. If this value is low, small bumps will cast shadows on the object's surface. This might cause jagged shadow edge between the sunny and shadowy side of the object, but it can be smoothed out by turning on Soft Shadows

接触阴影

这种阴影用来修复因为偏移或者阴影贴图采样不足引起的漏光。原理是使用深度缓冲区来查找遮挡物品(就像屏幕空间反射一样)。但它和屏幕空间反射有一样的缺陷，即效果在未知厚度物体上或者屏幕边缘消失。

Tip

尽量让接触阴影(Contact Shadows)的阴影小点，因为投影不够精确，并且无法遮蔽整个场景。

距离: 查找屏幕空间遮挡物体的空间距离。
偏移: 偏移用于光线跟踪以减少自阴影伪影。
厚(宽)度: 用于检测遮挡物体的像素厚度，将任何潜在的遮挡物体处理为此厚度。

级联阴影图

Sun lights usually illuminate a large scene with many objects, some close, some far away. To optimize shadow calculation in this situation, a technique called Cascaded Shadow Maps is used. The distance between the camera's near clip and far clip point is divided into as many equal intervals (called cascades) as you set the Count parameter below. For each cascade a different resolution shadow will be displayed: higher resolution for closer cascades and lower resolution for distant ones. Do note that cascade shadow maps are always updated because they depend on the camera position or your view origin in the 3D-Viewport. This means they have a high performance impact.

Note

因为在正交视图中，级联阴影贴图覆盖相机的整个深度范围，所以阴影精度呈均匀分布。

数量: Number of cascades to use. More cascades means better shadow precision but a lower update rate.
渐隐: When the Fade is greater than 0, the size of each cascade (distance interval) is increased so that neighboring cascades overlap. Then a fade is applied in the overlapping region to provide a smooth transition between cascades. Higher values mean the cascade's size is increased more, which decreases the available shadow resolution inside the cascade since some of it is used in the overlapping region.
最大距离: Distance away from the view origin (or camera origin if in camera view) to cover by the cascades. If the view far clip distance is lower than Max Distance, the view far clip distance will be used. Only works in perspective view.
分布: 使更多分辨率分布在近剪裁平面附近。仅适用于透视图。

局限

和Cycles不一样，eevee灯光的尺寸不会改变阴影的柔化程度。