CryENGINE-World Machine Tutorial 1 Impact Craters陨石坑.doc

World Machine Tutorial #1: Impact Craters(World Machine世界构造器：可用于游戏场景的地形场景制作软件是一个程序地形生成器，不同于你用过的任何一款地形生成软件。World Machine 混合了强大的地形效果，拥有图形界面 ，并能快速动态预览，帮助快速准确地创造出各种真实地貌。)陨石坑本教程由绿苹果翻译Summary: Beginning with a simple model and then adding progressively more sophisticated touches, you will learn a technique for creating a cratered terrain surface in World Machine. 内容摘要：开始时要做一个简单的模拟，然后增加更多的细节，那么，你就要学会用些技巧在world machine中Whether its the pockmarked barren surface of the moon or a massive terrestrial meteor crater, impact craters can add a very unique twist to the surface of a planet. Well look at a couple methods of creating craters on the existing terrain of your world, as well as how best to blend the crater into the existing terrain to simulate old or recent meteor activity. 无论是月球表面的小斑，还是星球表面的创孔，撞击的创坑可以给表面造成独特的旋状结构。现在，我们将要讲解一下，怎样在现有的地形上创建撞击大坑的方法，当然也会讲解怎样把大坑和星球地表混合，来制造出星球的被撞击的样子。As we step through the creation process, well look at exactly what to do in World Machine that would create the features that we need to represent. As a convenience, at the end of the tutorial you can also download the World Machine Terrain File that shows all of the techniques mentioned here. 步入制作的过程当中，我们将要考虑，怎样在world machine中创建一个所需要刻画的地表特征。为了方便起见，在教程的最后，我们也提供了范例文件下载。Method One: Hero CratersA Hero crater is an individually positioned unique crater. This is the kind of crater that might be found on Earth or another planet with an atmosphere and active geological processes that erase impact craters from the landscape over time. Lets take a look at some real life terrestrial craters: 方法一：巨坑巨坑是个有着独特地理位置的大坑。这就类似于地球上或其他星球上，由于大气，地质变化过程中，在地表撞击所留下的大坑。让我们来看看现实生活中的大坑。Some points to notice for our modelling attempt about the above images: 以上我们提到了在模拟地貌时所需要注意的几点Crater Shape: The Craters are remarkably - but not perfectly - circular in appearance. The wall profile looks something like a scaled inverted hemisphere. 坑的外形：坑的外形特征很明显，但是不规则-表面上看起来是圆的，但剖面却又很多类似于鳞状的锯齿。Crater Rim: Ringing the crater hole itself is a blast rim of raised land, that is sharp at the edge of the crater and tapers off gradually to the surrounding land. 坑的边缘：围绕坑的一圈突起的气流环状结构，这是围绕着坑的边缘，并且坡度逐渐平缓的一个结构。Erosion: Since these are terrestrial craters, geological processes act to erase the presence of the crater from the landscape over time. You can clearly see gullies and slumping happening on the sides of the crater wall, slowly producing a shallower crater. 侵蚀：从创坑的形成开始，随着时间的流逝，地质的变化会慢慢抹去创坑的一些细节，你可以在坑的边缘内壁上，清楚地看见雨水的冲刷和塌方的痕迹，慢慢地产生了些小的坑洼。Approach to Terrain ModellingThe first thing to realize is that there are many, many ways to create a given effect in World Machine. It may well take several tries using different methods before hitting upon a technique that works well in reproducing the effect you want.大概模拟出地貌开始，我们有太多的方法来创建地形效果，不过，我最好是先用一些不同的方法尝试，偶然发现了一个很好的方法，然后再用这个方法来创造你想要的地形效果。To complicate matters, some of the most useful tools for modelling specific landforms are only available in the Standard Edition and above. In this tutorial I will show how to work around the limitations of the Basic Edition where possible. 为了增加更多细节，一些细节地形工具只有在标准版的程序里有。在这个教程里，我将会尽可能地用基础版本来进行讲解The Starting TerrainLets create a basic terrain that well use to create our meteor impact crater upon. A Perlin Noise device set to Billowy and an Erosion device set to the Flood of Slurry preset creates the terrain shown below. 开始创建：让我们先创建一个基础地形，用于陨石的碰撞。Perlin Nosie节点让地形表面有大的起伏效果，Erosion节点让表面有泥浆冲刷效果。下面就是默认的预览地形The Crater ShapeThe basic crater shape will be created by a Radial Gradient device. This device can produce a cone shape. You can position it anywhere in the world that you want it by using the Transformation section of the Dialog. You can also control how large the crater will be with the Radius property of the device. 创坑的形态这个基本的形态可以由Radial Gradient （放射状斜坡）节点完成。这个节点可以产生一个锥形。你可以把它放到地图的任意位置。你也可以控制利用Radius(半径)属性来控制创坑的大小Next well use an Inverter device to invert the shape to create your garden-variety hole in the ground.下面 我们将要用Inverter(反转节点)来反转刚才的锥形，在地面上造一个坑Your next step will depend on if you are using the Standard or Basic edition of World Machine.下面一个步骤需要用到标准版或者基础版功能，两者有些区别STANDARD EDITIONConnect the output of the Inverter to a Curves device, and draw a curve that looks like the one shown here. The curve view shown here essentially is a profile view of what the sides of the crater will look like. It has steeply sloping sides, a noticable rim and then a gentle falloff to the surrounding terrain. Examing the 3D Preview, you can see that our basic crater shape is now formed; all that remains is to imprint it onto the terrain.标准版：把inverter(反转节点)连接到Curves(曲面节点)上,然后弄一个曲线就像这里显示的这样。这条曲线所形成的形状，实际上就是创坑的侧视剖面。显然，他这个坑有着一条突起的边缘，一条很明显的环状，最后边缘坡度又慢慢平缓。在3d预览窗口下，你可以看到基本的创坑形状已经初步形成了，现在，最后一个步骤就是要与基础地形结合起来了。BASIC EDITIONConnect the output of the Inverter to a Height Selector device, and set the device parameters as shown here. Essentially, we are using the selector to pick out the rim of the crater. By using the falloff set to maximum, and falloff mode set to Exponential, the crater has a slope that is approximately correct. If you compare the 3D Preview of this crater to the Standard Edition version using a handdrawn curve, you can see that it is quite similar!基本版：把inverter（反转节点）输出与Height Slector（高度选择节点）连接在一起，然后把参数设置成图中的一样。事实上，我们用selector(选择器)来制造创坑边缘的效果。使用falloff设定最大值，在falloff模式下设置成Exponential（指数）模式，创坑的斜度就差不多接近正确了。Imprinting the Crater onto the TerrainOur crater and the source terrain are both defined positively. In other words, the terrain and the crater are both oriented to look like what we envision the final result to be. Thus, to combine them we will need to add or average them together. A different way of creating craters might have the crater defined negatively, and then we could subtract it out from the terrain. They are simply different ways of producing a similar result. Here you can see that we have wired both the source terrain and the crater into a Combiner device set to Average mode.把创坑印刻在地形上：我们创坑和基础地形都是被定义为positively（绝对的，不太懂，可能和是正面的意思）。换句话说，地形和创坑看起来的样子和最终的结果是一样的。因此，把我们最后肯定是要把他们两个叠加起来。当然还有其他的方法可以创造创坑，把创坑的属性定义为negatively(否定的?不知道，可能负面的意思)，然后，我们可以把这个洞从地形上减去。用一些简单而不同的操作也可以产生相似的结果。现在我们可以看到，图中我们把连个形态都连接到了combiner上，使用的模式是Average(平均结合？)This is getting pretty close to what we want! For a quick crater off in the distance, we could stop here. But for a true Hero crater that will be in maximum detail in the foreground, we need to do even better. There are definitely some details that we can improve on.哈哈， 越来越接近我们想要的效果了。远处的形态已经初步形成了，我们可以先停在这。但是真正的大坑其实还有很多细节，这都需要们细心地去完善。Improving Crater Realism增加创坑的真实性细节STANDARD EDITION ONLY: Removing Underlying Detail from Inside the Crater标准版特有的功能：从创坑的内部去除底层的细节Although it is somewhat difficult to see with our choice of basic terrain, our method of cratering does NOT wipe out the original terrain shapes inside of the cratered zone. This can result in a very strange looking crater, as the impact of the crater should have erased those details from the blast zone. If we want erosion detail from post-impact erosion, we should add that in later, just like Mother Nature does. To the right you can see our crater applied to a more mountainous terrain. (As an aside, the only difference between this terrain and the previous one used was that the Erosion device is now set to the Classic WM + Power preset. The erosion device is VERY powerful!) Not good. The mountain landforms are still clearly present inside the blast zone. Luckily, this is something that can be very easy to fix!The solution is to smooth away the terrain details inside of the blast zone.虽然我很难用基础版的来做，但我们的露底的方法不会消除创坑内原始地形的样子。最终的样子看起来有点奇怪，因为撞击形成的坑会由于气流冲击抹去一些细节。如果你想要有被气流冲击的侵蚀效果，我们等下就会制作，就像真实的大自然所形成的那样。我们看到，图中的创坑和山地沟壑地区所结合起来的样子。（从图中各你可以看到，和前面制作好的地形相比，唯一不同的是，erosion（侵蚀节点）设置成了Classic WM + Power，erosion（侵蚀节点）事实上是一个功能很强大的节点！）恩还不够完美。山脉的地形结构还是覆盖了气流冲击的区域。当然，这是一个很容易可以解决的问题。解决方法就是在气流冲击区域平滑掉山脉原有的一些细节。We can use the Blur device in the Standard Edition to quickly smooth away the interior of the crater. The steps to do are: 1.Wire a Blur device to the output of the Combiner used above. 2.Splice a Splitter device into the network between the Inverter and the Curves devices you have already created. 3.From the second output of the Splitter device, add a Height Selector device that is connected to the Mask Input of the Blur device.Whew! When describing World Machine networks, a picture is usually worth a thousand words.我们在标准版的编辑器中可以用Blur（模糊节点）来快速平滑掉在创坑内部的细节。下面是几个步骤：1把Blur(模糊节点)连接到Combiner(合成节点)上2.在上面一创建好的节点网络中，在inverter（反转节点）和Curves(曲面节点)之间增加一个Splitter(分离节点)3.从Splitter(分离节点)的第二个输出，增加一个Height selector(高度选择节点)，连接到blur (模糊节点)的Mask input(遮罩输入)。Ok,千言万语不敌一张图说的清楚，请参照下面的图例Here you can see the settings used for the Height Selector: Notice how the output of the height selector has masked out the area of the inside of the crater. By applying this to the Mask Input of the Blur device, we have contained the blurring effect to happen only inside the crater. The Blur device should be set to a blur radius that matches your artistic preference.参照这里，你可以看到height selector(高度选择节点)的具体设置注意，heighr selector(高度选择节点)已经遮罩住了创坑的内部。把遮罩和模糊节点连接，那么模糊作用只会对遮罩部分起作用了。模糊节点应该设置模糊半径，这就看你的个感觉怎么样了。效果如上.good.Other Realism AdditionsThere are many things you can do to increase the realism of your Hero crater. Many of these are relatively simple additions, and make good exercises in using World Machine. Heres a small, partial list: 1.Blasted Area: If simulating a fresh impact onto the terrain, you might want to add some fine noise to the smooth areas to simulate the rough, blasted rock, or use a texturing mask and have your renderer do so. Alternatively, you may wish to erode the entire landscape again to simulate an aged crater. 2.Irregular Circle: Although craters are very circular, they are rarely perfectly circular like ours. Adding a little bit of wiggle to the circular shape of the crater can help with realism quite a bit, especially when the crater impacts otherwise flat areas. You can do this by adding a Simple Displacement device after the Circular Gradient that defines the crater shape. 3.Parameter Tuning: The correct settings for the crater shape and the crater combiner amount are going to vary with the source landscape that you are impacting it upon. Like many things in World Machine and Computer Graphics in general, small changes in parameters can cause some quite dramatic changes in the resulting image. Heres an example of the two terrains weve been working on with the above modifications.其他真实细节的添加：还有很多细节你可以添加，很多相关的简单叠加，可以很好地运用到你的练习作品当中。下面是一些说明。1. 冲击爆炸区域：如果要在地表模拟一个刚形成撞击效果，你也许希望在平滑区域增加一些精巧的噪波细节来模拟粗糙表面，碎石，或者用一个材质蒙版，尽量去表现其真实性。选择了了一种方法后，或许你可以模拟被侵蚀的整个区域来表现一个更苍老的创坑。2. 不规则的环状外形：尽管创坑是圆的，但外形并不是完美的圆，还是有些不规则的。在创坑外形上增加一点wiggle（不规则浮动，摆动）又可以变得更真实些。特别要注意的是，当撞击发上在平坦区域，你只需要简单地在Circular Gradien（环形坡度）后增加一个Displacement（位移节点）来定义创坑的形状。3. 参数调整: shape 和combiner参数的设置要参考撞击地点的地形的变化。和很多模拟软件一样，某些参数细微的变化会造成结果的巨大差异。 下面是两幅做好的地形looks goodMethod Two: Many Impact CratersSometimes we dont want a single crater - instead we want an entire field littered with them.方法二：很多创坑制造方法我们想要有不只一个坑，我们想要真个区域都有.It would be tedious at best to create the dozens or hundreds of craters visible above individually in World Machine! If we take the device network that we developed above for our hero crater, we could keep everything the same and achieve many craters if we just had a device that could make radial-gradient shapes all across the terrain. There are a few ways of doing this, but currently one of the best choices is to use some advanced features of the Voronoi Noise device.如果想要创建图中几十上百个的创坑，显然是件有些枯燥的事。如果我们用利用network来增加创坑，如果有一个节点可以在真个地形上创造出radial-gradient shapes（放射状坡度的形状），那么我们可以保留创坑留下的一切东西。有不知一种方法可以完成这个效果，不过，现在我只介绍一种最好的方法-使用一项高级功能,Voronoi Nose节点。The Voronoi device is capable of creating polka-dot patterns that will be ideal for us to base our crater on. For convenience, I have created a macro called Cracks and Dots that can create a polka-dot pattern. You can download the macro directly from here (Cracks and Dots.dev). Those curious can simply open the macro up and look inside to see how the dots are made. Essentially it is just the F1 noise type of the Voronoi device, clamped appropriately so that the dot features appear. The output of the Cracks and Dots macro is sent through an Inverter so that we have a field of circular depressions rather than circular lumps. Then the output is sent to the exact same Curves device that we used earlier to create our crater shape. You can s