Tips and Tricks

技巧和窍门

So where does the light actually come from?

那么光到底是从哪里来的呢？

Example 1

例子一

After objects have been placed and textured/colored, and the slightly reflective floor has been finished, you don’t have to be a rocket scientist to light this scene.

在物体被放置好并且有质感/有颜色，稍微反射的地板已经完成之后，你不需要成为一个火箭科学家来照亮这个场景。

In this scene, the only sources of light next to the Physical Sky are the two fluourescent lights at the left.

在这个场景中，物理天空旁边唯一的光源是左边的两盏荧光灯。

The Physical Sky and 2 Polygon Lights are used to light the scene. 物理天空和2个多边形灯光用来照亮场景

The front and rear of the room have openings that let a large amount of light in. Two types of light enter the room through these openings, both of which come from the Physical Sky:

房间的前面和后面都有开口，可以让大量的光线进入。两种类型的光线通过这些开口进入房间，这两种光线都来自物理天空:

The yellow sunlight that casts an Area shadow 黄色的阳光投射出一片区域的阴影
The bluish sky light that is emitted by a sky hemisphere. 蓝天半球发出的蓝色天空光

左边墙上的两个多边形灯(使用发光材质的物体)对整个房间的照明影响很小。右边电视机发出的标称光量根本不起作用

These few light sources are enough to achieve a realistic lighting of this scene. The bulk of the work is done by GI. Otherwise the PresetInterior High (High Diffuse Depth) will be used.

这几个光源足以实现这个场景的真实照明。大部分的工作是由 GI 完成的。否则，内部高(高漫射深度)将被使用。

A Physical Sky was used with a slightly raised Sky value and a much stronger Sun value applied.

物理天空使用略微提高的天空值和更强烈的太阳值应用。

Example 2

例子二

Scene by Holger Schömann. 场景作者: Holger sch ö mann

What sets this scene off, in addition to the dispersed reflection of the floor tiles and the displacement-generated area rug, is the HDRI lighting that was used.

设置这个场景，除了分散反射的地板砖和位移产生的地毯，是 HDRI 照明使用。

Light only enters this room through the window and the skylight! 光线只能通过窗户和天窗进入这个房间

This room has two relatively large openings through which light can enter - the skylight in the ceiling and the window. Both openings were defined as GI Portals in order to concentrate the GI calculations in the right areas. The light is generated via a HDRI texture on the Sky Object.

这个房间有两个相对较大的开口，光线可以通过这两个开口进入——天花板的天窗和窗户。两个开口都被定义为 GI 门户，以便将 GI 计算集中在正确的区域。光线是通过天空物体上的 HDRI 纹理产生的。

Example 3

例子3

4 Area lights are used to illuminate the Vase. 4区域照明灯用于照亮花瓶

What is it that makes this vase look so darn good? Actually, nothing special (except for the excellent composition of the scene itself … ): The scene is lit by four slightly blue and orange colored Area lights with Inverse Square falloff ("Details" tab). The falloff type is important since it most accurately simulates the falloff of real world light. Additionally, the Show in Reflection option has been activated for several of the Area lights, resulting in several reflections on the surface of the vase.

是什么让这个花瓶看起来这么好？实际上，没有什么特别的(除了场景本身的优秀构图...) : 场景是由四个略带蓝色和橙色的区域灯点亮的逆平方衰减(“细节”标签)。衰减类型很重要，因为它最精确地模拟了现实世界光的衰减。此外，显示在反射选项已经激活了几个区域灯，导致在花瓶表面的几个反射。

As you can see in the image above, the use of GI (IR+IRDiffuse Depth = 3) results in an even and very pleasant dispersion of light.

正如你在上面的图片中看到的，GI (ir + ird iffuse Depth = 3)的使用导致了均匀和非常令人愉快的光散射。

Outdoor Scenes

户外景色

Left: 左图:Diffuse Depth 漫射深度 = 1; right: Diffuse Depth = 3. The visible difference is minimal but the difference in render times is large. 右: 漫射深度 = 3。可见的差别很小，但是渲染时间的差别很大

For outdoor scenes that are illuminated primarily by the sky a Diffuse Depth value of 1 is sufficient since the sky emits light from just about every direction and almost all object surfaces "see" the sky and are illuminated by its light.

对于主要由天空照亮的户外场景，漫射深度值1就足够了，因为天空几乎从每个方向发射光线，几乎所有物体表面都“看到”天空，并被天空的光线照亮。

Color Mapping and 32-bit Rendering

彩色映射与32位渲染

Left a normal 8-bit rendering; at right the image rendered with Color Mapping. The only light source used was a Polygon Light (object with illuminating material applied). Scene by Holger Schömann. 左边是正常的8位渲染; 右边是用颜色映射渲染的图像。唯一使用的光源是一个多边形光(物体与照明材质应用)。场景作者: Holger sch ö mann

Balancing the brightness of a rendered image is very important for achieving optimal render results. Many times the brightness of a scene is inhomogeneous or contains faulty contrasts. Sometimes artists tend to pump up the brightness of the light sources if a scene is rendered too dark only to realize that these areas are then too brightly illuminated.

平衡渲染图像的亮度对于获得最佳渲染结果非常重要。许多时候，场景的亮度是不均匀的或包含错误的对比。有时候，艺术家们倾向于在场景渲染得过于黑暗的时候增加光源的亮度，结果却发现这些区域被照得过于明亮。

There are two ways in which this can be avoided:

有两种方法可以避免这种情况:

Color Mapping 彩色地图
32-bit 32位 rendering with subsequent editing in an image editing software that can edit 32-bit images and offers the necessary tools for editing 32-bit color depth (the current version of Photoshop offers only a limited number of tools for working with 32-bit images). 使用图像编辑软件进行渲染和后续编辑，该软件可以编辑32位图像，并提供编辑32位彩色深度所需的工具(目前版本的 Photoshop 只提供有限数量的处理32位图像的工具)

Both methods basically do the same thing - they take rendered images with greater color depths and converts them to 8-bit images.

这两种方法基本上做同样的事情-他们采取更大的颜色深度渲染图像，并将它们转换为8位图像。

Exclude Glass from GI

从 GI 中排除玻璃

Each of the transparent objects was excluded from GI in a different manner. Render times increased from left to right. Not how dark the shadows were rendered in the middle image. 每个透明物体都以不同的方式被排除在 GI 之外。渲染时间从左到右增加。而不是中间的阴影渲染得有多黑

Depending on the scene you exclude an object from GI by

根据场景的不同，你可以从 GI 中排除一个物体

applying a Compositing tag ( 应用合成标记(Seen by GI 美国大兵看到 option) … 选项)
or in the material channel ( 或在物质通道(Receive GI 接收 GI option or 选择或Generate GI 生成 GI for Caustics), which lets you "block" GI for certain materials (this occurs automatically for transparent materials with 为焦散) ，它可以让你“阻止”某些材质的 GI (这是自动发生透明材质与Receive GI 接收 GI - see also - 请参阅Glass/Mirror Optimization 玻璃/镜子优化).

Due to its transparency, glass can easily be excluded from GI since the effect is so minimal and the render times can thereby be reduced.

由于其透明度，玻璃可以很容易地从 GI 排除，因为效果是如此微小，渲染时间可以因此减少。

You basically have to decide on an individual basis whether or not applying GI to a glass object in your scene will make a noticeable or important difference in the final rendered image. Use the image above as a reference.

你基本上必须根据个人情况来决定是否将 GI 应用到场景中的一个玻璃物体上，这会在最终渲染的图像中产生显著或重要的差异。使用上面的图片作为参考。

GI and Baking Textures

GI 和烘焙纹理

See Bake Object

参见 Bake Object

GI and Specular Highlights

和 Specular Highlights

Note that the material’s Specular Color channel will be ignored when only GI is used to illuminate a scene (without using Cinema 4D light objects and only using luminous objects). So, why is this?

注意，材质的镜面色彩通道将被忽略时，只有 GI 是用来照亮一个场景(不使用Cinema 4D 光物体，只使用发光物体)。那么，这是为什么呢？

Well, both effects are simply well-functioning illusions to make materials look realistic using common, often spherically shaped (i.e. very small) sources of light. In the real world, specular highlights are merely a reflection of area light.

好吧，这两种效果只是简单的运作良好的幻觉，使材质看起来真实使用共同的，通常是球形(即非常小)的光源。在现实世界中，高光只是区域光的反射。

For the calculation of GI this means the following: Specular highlights are adjusted using the Reflectance channel and the size/color of the luminous object.

对于 GI 的计算，这意味着如下: 镜面高光部分使用反射通道和发光物体的大小/颜色进行调整。

Of course you can also create additional Cinema 4D light sources that affect specific objects in order to create more specular highlights. This may not be in harmony with the principle of a true global illumination but what counts is the final result!

当然，你也可以创建额外的C4D 光源，影响特定的对象，以创造更多的镜面高光。这可能不符合真正的全局光源原则，但重要的是最终的结果！

GI and Animation

GI 和动画

GI and animations are technically challenging. If a single image takes a long time to render using GI, then rendering an animation with a series of these images will require very long render times. In addition, Irradiance Cache tends to flicker if its settings are set too low.

GI 和动画在技术上是具有挑战性的。如果使用 GI 渲染一个图像需要很长时间，那么使用一系列这些图像渲染一个动画将需要很长的渲染时间。此外，如果设置太低，辐照度缓存将会闪烁。

You should adhere to the following when creating animations with GI:

在使用 GI 创建动画时，你应该遵循以下原则:

When using IR+IR/IR+QMC: if flickering occurs on surfaces, the 当使用 ir + ir/ir + qmc 时: 如果表面发生闪烁，则Samples 样本 value probably too low (four-digit figures may even be required). If, on the other hand, flickering occurs in small regions around an object, the 价值可能太低(甚至可能需要四位数字)。另一方面，如果闪烁出现在物体周围的小区域，则Record Density 记录密度 value is too low. In this case, decreasing the 在这种情况下，减少Maximum Spacing 最大间距 value should help. If this does not do the trick, set the 如果这不起作用，设置Record Density 记录密度 to a higher setting. 提升到更高的境界
Flickering can even occur at optimized IR+LM settings if the base light map is of poor quality (see ,Optimize Light Mapping’ below). 闪烁甚至可以发生在优化的红外 + lm 设置，如果基础光贴图质量差(见下面的优化光贴图)
QMC+QMC will not flicker (the render times will increase accordingly; these will be at a maximum). Qmc + qmc 将不会闪烁(渲染时间将相应增加; 这将是最大值)

Camera Animation and Full Animation

摄像机动画和全动画

Irradiance Cache offers the following animation types:

Irradiance Cache 提供以下动画类型:

Use Camera Path 使用相机路径: Only the camera is in motion and all other Project elements remain unchanged with regard to lighting - no objects and no lights move. This makes it easy for Irradiance Cache because it can use a single, non-flickering cache for the entire animation. The : 只有相机在运动，所有其他项目元素在照明方面保持不变——没有物体，没有灯光移动。这使得它很容易为辐照度缓存，因为它可以使用一个单一的，不闪烁的缓存为整个动画。这个Full Animation Mode 全动画模式 must be disabled (and 必须是禁用的(及Use Camera Path 使用相机路径 enabled if light maps are used). You can also use tricks (see 你也可以使用一些技巧(参见Prepass Only 只准备) to get the desired result. )来获得期望的结果

Tip: 提示:
Note that when rendering via Team Render, working with a cache is only effective if a single cache (that can only be generated without Team Render on a single computer) is available for distribution prior to rendering. This cache can then be distributed to the render clients ( 请注意，在通过 Team Render 进行呈现时，只有在呈现之前有一个缓存可用于分发时，使用缓存才有效(只有在单台计算机上不使用 Team Render 才能生成缓存)。然后，这个缓存可以被分发到呈现客户端(Auto Load 自动加载 option enabled). 选项启用)

Full Animation 全动画: For a different lighting situation in which objects and/or lights are animated, a separate cache must be rendered for each image. If you do not want to load or save GI cache files, disable : 对于物体和/或灯是动画的不同照明情况，必须为每个图像渲染一个单独的缓存。如果不想加载或保存 GI 缓存文件，请禁用Auto Save 自动保存 and 及Auto Load 自动加载 (Cache Files 缓存文件 tab) for all cache types involved. Deactivate all options pertaining to camera animations (such as 选项卡) ，用于所有涉及的缓存类型。停用所有与相机动画相关的选项(如Use Camera Path 使用相机路径 for light mapping). 为光线绘图)

If you want to load/save cache files, Auto Load, Auto Save and Full Animation Mode must be enabled for all cache types involved.

如果您想加载/保存缓存文件，则必须为所有相关的缓存类型启用“自动加载”、“自动保存”和“全动画模式”。

GI Caches and Team Render

GI 缓存和团队渲染

How do GI and Team Render work together?

GI 和团队渲染如何一起工作？

Stills

剧照

With still you don’t have to make any changes; using the default render settings (not the Render Settings in conjunction with this), all Render Clients will participate in rendering a single cache file, which will also be used by all Render Clients during rendering.

尽管如此，你仍然不需要做任何更改; 使用默认的渲染设置(不是与此相关的渲染设置) ，所有的渲染客户端将参与渲染一个单一的缓存文件，这也将被所有的渲染客户端在渲染期间使用。

Animation

动画

First you must ascertain if a Camera Aniamtion or a Full Animation is being rendered (see above for an explanation of how these differ).

首先你必须确定是否一个相机分离或一个完整的动画被渲染(见上面的解释这些如何不同)。

Full Animation 全动画: This can be sent directly to Team Render for rendering. Make sure that the : 这可以直接发送到团队渲染渲染。请确保Full Animation 全动画 option is enabled in the 选项中启用Cache Files 缓存文件 tab. 标签
Camera Animation 摄像机动画: All caches must first be pre-calculated without Team Render (this is the only way to achieve flicker-free results). Subsequently, the scene can be rendered in Team Render, including cache files. : 必须首先在不使用 Team Render 的情况下预先计算所有缓存(这是实现无闪烁结果的唯一方法)。随后，场景可以在 Team Render 中渲染，包括缓存文件

The following applies to both methods: If pre-calculated cache files exist that should be used with Team Render, the Auto Load option must be enabled in the Cache Files tab.

以下内容适用于这两种方法: 如果存在应该与 Team Render 一起使用的预计算缓存文件，则必须在 Cache Files 选项卡中启用 Auto Load 选项。

If QMC Rendering is being used, which does not require caches, it can also be sent directly to Team Render.

如果正在使用 QMC Rendering，它不需要缓存，它也可以直接发送到 Team Render。

Optimizing Light Mapping

优化光线映射

Unfortunately, light maps are not particularly constant from one animation frame to the next. In addition, light leaks can suddenly occur, which negatively effect the GI calculation. Try the following:

不幸的是，光影贴图并不是每一帧动画都是固定不变的。此外，光泄漏可能会突然发生，这对 GI 计算产生负面影响。试试以下方法:

Experiment with 试验一下Prefilter 预过滤器 (faster) and (更快)及Interpolation Method 插值方法 (slower) in the (慢)在Light Mapping 光线测绘 tab. Light maps can be smoothed to a certain degree, which reduces the differences between subsequent light maps. Larger 标签。光照贴图可以被平滑到一定程度，这样可以减少后续光照贴图之间的差异。更大Sample Count 样本数量 values are also helpful because they also have a smoothing effect. 值也很有用，因为它们也有平滑效果
Single-polygonal wall strengths can lead to light leaks (small, very bright spots). Make sure walls are created with the proper volume (i.e., thickness). 单边多边形墙壁的强度可能导致漏光(小，非常明亮的点)。确保墙壁的体积(即厚度)合适
If widespread flickering occurs at corners/bevels when using IR+LM, increase the 如果使用 ir + lm 时在角落/斜面发生广泛的闪烁，则增加Path Count (x1000) 路径计数(x1000) value. If flickering only occurs in a small, isolated region, reducing the 如果闪烁仅发生在一个小的、孤立的区域，则会减少Samples Size 样本数量 value can help (the 价值可以帮助(Path Count (1000s) 路径计数(1000秒) value might have to be increased to compensate). 价值可能不得不增加以弥补)