ue4商城资源Volumetric Spotlight with Shadow带阴影的体积聚光灯

Unreal Engine虚幻游戏引擎素材资源 Unreal Engine Marketplace –Volumetric Spotlight with Shadow带阴影的体积聚光灯
“体积聚光灯效果”（Volume spotlight effect）将灯光反射到聚光灯中的尘埃粒子、雾或湿气的物理效果可视化。一个体积的错觉是通过在圆锥体上填充一系列的平面来实现的。
形状可以通过设置其宽度和长度的参数来控制，您可以选择将其设置为方形。也可以设置颜色。
由于体积是通过垂直于聚光灯的附加透明平面（由参数设置（默认为512）），因此渲染成本非常高，因为实际上必须渲染整个体积，而3D渲染通常只渲染曲面。为了防止出现最坏的情况，将根据到摄影机的距离动态减少平面的数量。所有性能设置都是可配置的。请注意，这种效果只会在中端和高端机器上以相当好的帧速率（30FPS+）呈现。
这种光的酷之处在于它还支持（动态）遮罩。这些方法只需在平面上渲染的材质着色器的正确位置插入2D遮罩并进行变换。因此，只支持垂直于光线的2D遮罩，但简单的几何体（例如球体）在3D中渲染完全正确。这可以产生真正令人信服的效果，例如通过窗户或面板的光线，这使得体积效果比简单的面对面面上帝射线更强大、更凉爽。
技术细节
配置聚光灯的1个基本蓝图（支持1个阴影遮罩）
1个Blueprint子级，最多支持4个阴影遮罩和一些更真实的灯光计算，但会导致更高的渲染成本。
2个蓝图，方便配置虚幻引擎的内置体积。（这些只是通过渲染聚光灯体积的表面来模拟体积）
2个演示级别，共有10个聚光灯示例。
3个灯罩支柱
1个燃料灯支柱
5风机材料。
沙坑演示包含24种材料作为奖励
蝴蝶演示包含一个很好的地面和水材料。
注意：由于渲染成本较高，此效果仅适用于中高端机器（站在聚光灯内是最坏的情况，在1920×1200的中档机器上，FPS将从50降到20 FPS（已经使用因子4的平面分辨率降低优化，因此会降低效果的某些质量（平面（边）变得稍微可见）。渲染多个聚光灯并从远处观察它们并不是一个真正的问题，因为这与聚光灯的数量（用4个测试）无关，而更多的是关于屏幕填充率。如果你想有一个动态阴影maks，最好一次只在屏幕上添加一个聚光灯，因为动态遮罩需要更新所有（512）个平面的材质，这是非常昂贵的性能。
The volumetric spotlight effect visualizes the physical effect of light reflecting of dust particles, fog or damp in a spotlight. The illusion of a volume is created by filling the cone with a series of planes to make it “volumetrical”.

The shape is controllable by setting parameters of its width and length and you can choose to have it square. The color can also be set.

Since the volume is rendered by additive-transparant planes perpendicular to the spotlight (set by a parameter (default 512)), the render cost is very high, because really the entire volume has to be rendered, while 3D-rendering usually just renders surfaces. To prevent the worst case conditions, the number of planes are dynamically reduced depending on the distance to the camera. All performance settings are configurable. Please note that this effect will only render at a decent framerate (30FPS+) on mid-end and high-end machines.

The cool thing about this light is that it also supports (dynamic) masks. These work by just inserting a 2D mask at the correct position and transformation in the material shader that is rendered over the plane. So only 2D masks perpendicular to the lightray are supported, but simple geometry (Example a sphere) renders completely correct in 3D. This can make real convincing effects such as light through windows or panels, which makes the volumetric effect really strong and much cooler than the simple facing-plane god-rays.
技术细节
1 base Blueprint to configure the spotlight (supports 1 shadow mask)
1 Blueprint child that supports up to 4 shadow masks and some more realistic light computation, but results in a much higher render cost.
2 Blueprints to easily configure the built in volumetrics of the Unreal Engine. (These just imitate volumetrics by rendering the surface of a spotlight volume)
2 Demo levels with a total of 10 examples of the spotlight.
3 props of spotlight casings
1 prop of a bunkerlamp
5 Materials of fans.
Bunker Demo contains 24 materials as a bonus
Butterfly Demo contains a nice ground and water material.

NOTE: Due to the high render cost this effect is only suited for mid to high end machines (standing inside the spotlight is worst-case condition and FPS will drop from 50 to 20 FPS on a mid-range machine at 1920×1200 (Already with plane resolution reduction optimization with a factor 4, so on the expense of loosing some quality of the effect (the planes (edges) become slightly visible))). Rendering multiple spotlights and looking at them from a distance is not really a problem, since it is not so much about the amount of spotlights (tested with 4), but more about the screen fill-rate. If you want to have a dynamic shadow maks, it is best to only add 1 spotlight at a time on the screen, because for dynamic masking it is needed to update the materials of all (512) planes, which is very performance costly.
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