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

World Machine Tutorial #1: Impact Craters(World Machine世界構(gòu)造器：可用于游戲場景的地形場景制作軟件是一個程序地形生成器，不同于你用過的任何一款地形生成軟件。World Machine 混合了強大的地形效果，擁有圖形界面 ，并能快速動態(tài)預(yù)覽，幫助快速準確地創(chuàng)造出各種真實地貌。)隕石坑本教程由綠蘋果翻譯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. 內(nèi)容摘要：開始時要做一個簡單的模擬，然后增加更多的細節(jié)，那么，你就要學會用些技巧在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. 無論是月球表面的小斑，還是星球表面的創(chuàng)孔，撞擊的創(chuàng)坑可以給表面造成獨特的旋狀結(jié)構(gòu)?，F(xiàn)在，我們將要講解一下，怎樣在現(xiàn)有的地形上創(chuàng)建撞擊大坑的方法，當然也會講解怎樣把大坑和星球地表混合，來制造出星球的被撞擊的樣子。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. 步入制作的過程當中，我們將要考慮，怎樣在world machine中創(chuàng)建一個所需要刻畫的地表特征。為了方便起見，在教程的最后，我們也提供了范例文件下載。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：巨坑巨坑是個有著獨特地理位置的大坑。這就類似于地球上或其他星球上，由于大氣，地質(zhì)變化過程中，在地表撞擊所留下的大坑。讓我們來看看現(xiàn)實生活中的大坑。Some points to notice for our modelling attempt about the above images: 以上我們提到了在模擬地貌時所需要注意的幾點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：坑的外形特征很明顯，但是不規(guī)則-表面上看起來是圓的，但剖面卻又很多類似于鱗狀的鋸齒。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. 坑的邊緣：圍繞坑的一圈突起的氣流環(huán)狀結(jié)構(gòu)，這是圍繞著坑的邊緣，并且坡度逐漸平緩的一個結(jié)構(gòu)。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. 侵蝕：從創(chuàng)坑的形成開始，隨著時間的流逝，地質(zhì)的變化會慢慢抹去創(chuàng)坑的一些細節(jié)，你可以在坑的邊緣內(nèi)壁上，清楚地看見雨水的沖刷和塌方的痕跡，慢慢地產(chǎn)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.大概模擬出地貌開始，我們有太多的方法來創(chuàng)建地形效果，不過，我最好是先用一些不同的方法嘗試，偶然發(fā)現(xiàn)了一個很好的方法，然后再用這個方法來創(chuàng)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. 為了增加更多細節(jié)，一些細節(jié)地形工具只有在標準版的程序里有。在這個教程里，我將會盡可能地用基礎(chǔ)版本來進行講解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. 開始創(chuàng)建：讓我們先創(chuàng)建一個基礎(chǔ)地形，用于隕石的碰撞。Perlin Nosie節(jié)點讓地形表面有大的起伏效果，Erosion節(jié)點讓表面有泥漿沖刷效果。下面就是默認的預(yù)覽地形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. 創(chuàng)坑的形態(tài)這個基本的形態(tài)可以由Radial Gradient （放射狀斜坡）節(jié)點完成。這個節(jié)點可以產(chǎn)生一個錐形。你可以把它放到地圖的任意位置。你也可以控制利用Radius(半徑)屬性來控制創(chuàng)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 我們將要用Inverter(反轉(zhuǎn)節(jié)點)來反轉(zhuǎn)剛才的錐形，在地面上造一個坑Your next step will depend on if you are using the Standard or Basic edition of World Machine.下面一個步驟需要用到標準版或者基礎(chǔ)版功能，兩者有些區(qū)別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.標準版：把inverter(反轉(zhuǎn)節(jié)點)連接到Curves(曲面節(jié)點)上,然后弄一個曲線就像這里顯示的這樣。這條曲線所形成的形狀，實際上就是創(chuàng)坑的側(cè)視剖面。顯然，他這個坑有著一條突起的邊緣，一條很明顯的環(huán)狀，最后邊緣坡度又慢慢平緩。在3d預(yù)覽窗口下，你可以看到基本的創(chuàng)坑形狀已經(jīng)初步形成了，現(xiàn)在，最后一個步驟就是要與基礎(chǔ)地形結(jié)合起來了。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（反轉(zhuǎn)節(jié)點）輸出與Height Slector（高度選擇節(jié)點）連接在一起，然后把參數(shù)設(shè)置成圖中的一樣。事實上，我們用selector(選擇器)來制造創(chuàng)坑邊緣的效果。使用falloff設(shè)定最大值，在falloff模式下設(shè)置成Exponential（指數(shù)）模式，創(chuàng)坑的斜度就差不多接近正確了。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.把創(chuàng)坑印刻在地形上：我們創(chuàng)坑和基礎(chǔ)地形都是被定義為positively（絕對的，不太懂，可能和是正面的意思）。換句話說，地形和創(chuàng)坑看起來的樣子和最終的結(jié)果是一樣的。因此，把我們最后肯定是要把他們兩個疊加起來。當然還有其他的方法可以創(chuàng)造創(chuàng)坑，把創(chuàng)坑的屬性定義為negatively(否定的?不知道，可能負面的意思)，然后，我們可以把這個洞從地形上減去。用一些簡單而不同的操作也可以產(chǎn)生相似的結(jié)果?，F(xiàn)在我們可以看到，圖中我們把連個形態(tài)都連接到了combiner上，使用的模式是Average(平均結(jié)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， 越來越接近我們想要的效果了。遠處的形態(tài)已經(jīng)初步形成了，我們可以先停在這。但是真正的大坑其實還有很多細節(jié)，這都需要們細心地去完善。Improving Crater Realism增加創(chuàng)坑的真實性細節(jié)STANDARD EDITION ONLY: Removing Underlying Detail from Inside the Crater標準版特有的功能：從創(chuàng)坑的內(nèi)部去除底層的細節(jié)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.雖然我很難用基礎(chǔ)版的來做，但我們的露底的方法不會消除創(chuàng)坑內(nèi)原始地形的樣子。最終的樣子看起來有點奇怪，因為撞擊形成的坑會由于氣流沖擊抹去一些細節(jié)。如果你想要有被氣流沖擊的侵蝕效果，我們等下就會制作，就像真實的大自然所形成的那樣。我們看到，圖中的創(chuàng)坑和山地溝壑地區(qū)所結(jié)合起來的樣子。（從圖中各你可以看到，和前面制作好的地形相比，唯一不同的是，erosion（侵蝕節(jié)點）設(shè)置成了Classic WM + Power，erosion（侵蝕節(jié)點）事實上是一個功能很強大的節(jié)點！）恩還不夠完美。山脈的地形結(jié)構(gòu)還是覆蓋了氣流沖擊的區(qū)域。當然，這是一個很容易可以解決的問題。解決方法就是在氣流沖擊區(qū)域平滑掉山脈原有的一些細節(jié)。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.我們在標準版的編輯器中可以用Blur（模糊節(jié)點）來快速平滑掉在創(chuàng)坑內(nèi)部的細節(jié)。下面是幾個步驟：1把Blur(模糊節(jié)點)連接到Combiner(合成節(jié)點)上2.在上面一創(chuàng)建好的節(jié)點網(wǎng)絡(luò)中，在inverter（反轉(zhuǎn)節(jié)點）和Curves(曲面節(jié)點)之間增加一個Splitter(分離節(jié)點)3.從Splitter(分離節(jié)點)的第二個輸出，增加一個Height selector(高度選擇節(jié)點)，連接到blur (模糊節(jié)點)的Mask input(遮罩輸入)。Ok,千言萬語不敵一張圖說的清楚，請參照下面的圖例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.參照這里，你可以看到height selector(高度選擇節(jié)點)的具體設(shè)置注意，heighr selector(高度選擇節(jié)點)已經(jīng)遮罩住了創(chuàng)坑的內(nèi)部。把遮罩和模糊節(jié)點連接，那么模糊作用只會對遮罩部分起作用了。模糊節(jié)點應(yīng)該設(shè)置模糊半徑，這就看你的個感覺怎么樣了。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.其他真實細節(jié)的添加：還有很多細節(jié)你可以添加，很多相關(guān)的簡單疊加，可以很好地運用到你的練習作品當中。下面是一些說明。1. 沖擊爆炸區(qū)域：如果要在地表模擬一個剛形成撞擊效果，你也許希望在平滑區(qū)域增加一些精巧的噪波細節(jié)來模擬粗糙表面，碎石，或者用一個材質(zhì)蒙版，盡量去表現(xiàn)其真實性。選擇了了一種方法后，或許你可以模擬被侵蝕的整個區(qū)域來表現(xiàn)一個更蒼老的創(chuàng)坑。2. 不規(guī)則的環(huán)狀外形：盡管創(chuàng)坑是圓的，但外形并不是完美的圓，還是有些不規(guī)則的。在創(chuàng)坑外形上增加一點wiggle（不規(guī)則浮動，擺動）又可以變得更真實些。特別要注意的是，當撞擊發(fā)上在平坦區(qū)域，你只需要簡單地在Circular Gradien（環(huán)形坡度）后增加一個Displacement（位移節(jié)點）來定義創(chuàng)坑的形狀。3. 參數(shù)調(diào)整: shape 和combiner參數(shù)的設(shè)置要參考撞擊地點的地形的變化。和很多模擬軟件一樣，某些參數(shù)細微的變化會造成結(jié)果的巨大差異。 下面是兩幅做好的地形looks goodMethod Two: Many Impact CratersSometimes we dont want a single crater - instead we want an entire field littered with them.方法二：很多創(chuàng)坑制造方法我們想要有不只一個坑，我們想要真?zhèn)€區(qū)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.如果想要創(chuàng)建圖中幾十上百個的創(chuàng)坑，顯然是件有些枯燥的事。如果我們用利用network來增加創(chuàng)坑，如果有一個節(jié)點可以在真?zhèn)€地形上創(chuàng)造出radial-gradient shapes（放射狀坡度的形狀），那么我們可以保留創(chuàng)坑留下的一切東西。有不知一種方法可以完成這個效果，不過，現(xiàn)在我只介紹一種最好的方法-使用一項高級功能,Voronoi Nose節(jié)點。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