Blender燈光和渲染第五章.doc

Indoor Lighting: Setting Up 室內(nèi)燈光的建立Now that were familiar with how to light a scene with the characteristics of outdoor lighting, its time to take the next step and look at lighting interior spaces. Many of the techniques we used to light our last scene will transfer to this project quite nicely.現(xiàn)在我們已經(jīng)熟悉了典型的場景照明，現(xiàn)在看看室內(nèi)空間。在上個(gè)場景我們用來照明的技術(shù)都可以非常適當(dāng)?shù)霓D(zhuǎn)到這個(gè)項(xiàng)目。However, there are some important differences that were going to have to discuss that are unique to interior lighting. Were going to take a look at:然而,它們有一些很重要的不同之處，我們將討論這些室內(nèi)燈光的不同之處。我們將要學(xué)習(xí)的是： Setting up our scene for use with a complex lighting system使用復(fù)雜的燈光系統(tǒng)設(shè)置我們的場景 Implementing a more complex lighting system使用更復(fù)雜的燈光系統(tǒng) Setting up lights to reflect artificial lights in our scene, intuitively在我們的場景建立人造的反射燈光。Lets get started!準(zhǔn)備開始學(xué)習(xí)！The first few steps 第一步Before we begin, we need to know what our scene looks like. If you havent already, go to the website (/lighting-and-rendering) and download the file interior.blend from the Interior Lighting download section. This is the file we will be using over the course of this project.在我們開始前，我們需要知道我們的場景是怎么樣的。如果你沒有場景，到站點(diǎn)/lighting-and-rendering從Interior Lighting下載interior.blend文件。這個(gè)文件將被用在我們的課程項(xiàng)目。If you open it, it should look similar to the following image:如果你打開了該場景，應(yīng)該看到類似如下的圖像：Diving inNow that we have the right scene, lets get started. In the last project, the first step we learned was to evaluate our scene. In our case, we are really going to have to carefully consider how were going to set up our lights. Lets take a moment and take a look at that now.現(xiàn)在，我們有正確的場景，讓我們開始。在上一個(gè)項(xiàng)目，第一步學(xué)習(xí)了評估我們的場景。在我們的案例，我們必須認(rèn)真的考慮怎么建立我們的燈光。讓我們現(xiàn)在去看看。Enhancing our render using layersWith more complex scenes, Blenders layer system becomes an invaluable tool for lighting. Many times, well find that there are some objects that need unique lighting setups that arent necessarily needed for the entire scene. To set up those unique mini light rigs, we need to link certain lights to specific layers, which we learned how to do in the last project. But we have a problemright now, our scene is all on one layer. This means, we have to decide how we want to break up the objects in our scene so we can light them properly.對于更更復(fù)雜的場景，Blender的層變成一個(gè)非常重要的工具。許多時(shí)候，我們發(fā)現(xiàn)一些物體需要獨(dú)特的燈光系統(tǒng)，但又不需要應(yīng)用到整個(gè)場景。要建立這些“迷你”的燈光系統(tǒng)，我們需要在特定的層創(chuàng)建燈光，在上個(gè)項(xiàng)目我們已經(jīng)學(xué)習(xí)了這樣的做法。但現(xiàn)在我們有一個(gè)問題是我們所有的場景都在同一個(gè)層。這意味著，我們要怎么打破我們的場景物體讓我們可以適當(dāng)?shù)恼彰魉鼈?。Lets take a quick lookBefore we begin, we need to figure out what kind of mood we want to set. For this scene, were going to want to focus on the wine bottle in the foreground, muting the background a bit using darker lighting and a slight change in focus. This will make the wine bottle the most prominent aspect of our scene. 在我們開始前，我們需要明白我們需要設(shè)置的氣氛種類。對于我們的這個(gè)場景我們想要的是聚焦在我們的葡萄酒瓶，讓背景使用暗色的燈光讓我們的葡萄酒瓶在場景更突出。Now, lets figure out where our light will primarily be coming from. We have two physical sets of light sources in our scenethe hanging lamps on the right and the embedded ceiling lamps on the left. We can use Spot lamps to simulate the hanging lamps on the right, and for the others, we can use Area lamps. Note that these Blender lamps arent visible in the Blender file; in fact, they dont even exist yet. We are going to add them together later in the chapter. 現(xiàn)在，讓我們看看我們場景的燈光來自哪里。在我們的場景設(shè)置有兩組光源在右邊的掛燈和左邊的天花燈。我們使用聚光燈（Spot）來模擬我們右邊的掛燈，對于其它的燈光，我們使用區(qū)域（Area）燈光。注意這些Blender燈光在這個(gè)Blender文件是不可見的；甚至它們還沒有存在這個(gè)場景。我們將在本章的后面添加它們。Adding these lamps will light a good majority of our scene, but we still need to light the wine bottle in a way that makes it stand out from the rest of the scene. Because this is the focus of our scene, were going to use a completely separate light to light it. In order for us to separate these light rigs properly, were going to need to set up our scene in layers. 添加這些燈光能夠很好的照明我們的場景，但我們還需要照明葡萄酒瓶，確保它從場景中突出來。因?yàn)樗俏覀儓鼍暗慕裹c(diǎn)，我們將完全使用一個(gè)獨(dú)立的燈光來照明它。為了適當(dāng)?shù)姆蛛x這些燈光系統(tǒng)，我們將需要建立我們的場景層。Organizing our layers 組織層In the real world, objects we see are affected by all available sources of light. In computer graphics, though, we have complete control over how light affects our scene, and as a result, we have the artistic liberty to create effects with light that may not necessarily occur in a naturally-lit scenario for the sake of visual appeal. In Blender, we can separate our light sources using three-dimensional layers, which behave in the same way as layers in Adobe Photoshop or the GIMP. By default, Blender assigns every new object we create to the first layer, but we can move these objects around to fit the needs of our scene. 在真實(shí)的世界，物體是由所有的光源的影響。在電腦圖形領(lǐng)域，雖然，我們可以完全控制燈光是怎么影響我們的場景，結(jié)果是，我們可以創(chuàng)建許多在我們自然界不會發(fā)生的藝術(shù)效果。在Blender,我們可以像Adobe Photoshop或GIMP那樣使用層單獨(dú)分離我們的光源，Blender指定新的物體創(chuàng)建在第一層，但我們可以移動它們到其它的層。Deciding which layers to use solely depends on the preferences of the user and the needs of the scene. As long as the layers are used in a way that produces the desired result in the render, there is no wrong way to use them. Lets take a look at how we can use layers in our own scene!使用哪一個(gè)層取決于用戶的喜好和場景的需要。既然層是以這樣的一種方式來實(shí)現(xiàn)想要的渲染結(jié)果，這是沒有錯誤的使用方法。讓我們看看怎么在我們自己的場景使用層！We know we need to light our wine bottle separately. This means that we need to have, at the very least, the wine bottle and the table its on, placed on a layer of their own. For logics sake, were going to leave these two on the first layer to start. Because the wine bottle is the focus of the scene, it makes sense to have it on the primary layer. Because were not sure whether or not were going to need to break up our scene further, lets place everything else in our scene on the layer directly below the first layer on the Move to Layer dialog box. Thats probably confusing to take in all at once, so heres an image to help you. 我們知道我們需要單獨(dú)的照明我們的葡萄酒瓶。這意味著我們需要，至少需要葡萄酒瓶和桌子在一個(gè)單獨(dú)的層，所以首先我們需要的是讓它們從第一層分離。因?yàn)槠咸丫破渴菆鼍暗慕裹c(diǎn)，它制造場景在在最原始的層。因?yàn)槲覀儾淮_定我們將來是否或不需要分離我們的場景，我們在Move to Layer對話框的第一個(gè)層創(chuàng)建我們所有的物體。這全部同時(shí)或許是很混亂的。所以這里有一個(gè)圖像可以幫助你。To do this, follow these steps: 要做這些，跟隨以下的這些步驟：1. Select everything in our scene, except for the wine bottle and the table its on. The easiest way to do this is to select everything in our scene, with the exception of the camera, and then deselect the wine bottle and table. 選擇場景的所有東西，除了葡萄酒瓶和它所在的桌子。最簡單的方法是全選所有的物體，然后取消選擇葡萄酒瓶和它所在的桌子。2. Press the M-hotkey to bring up the Move to Layer dialog box. 按M鍵彈出Move to Layer對話框。3. Select the layer button directly below the current layer (the first layer).選擇想要的層。This moves everything selected to the designated layer. 這將移動所有選擇的物體都指定的層。Lets assume for a moment that were going to use a 3-Point light rig to light our wine bottle similar to the light rig we used for the tricycle in our last project. This means that were going to want our key light to light both the wine bottle and the table. We need this light to affect the table so we can render any shadows cast by the wine bottle. 假定我們使用類似我們上章節(jié)所使用的三點(diǎn)照明系統(tǒng)照明我們的葡萄酒瓶。這意味著我們需要主光照明我們的葡萄酒瓶和桌子。我們需要照明桌子效果讓我們能夠渲染任何的葡萄酒瓶產(chǎn)生的陰影。The side light and rim light, on the other hand, only need to affect the wine bottle itself, not the table. This means were going to have to move the table once more, this time to layer two. Following the same steps we used to move our objects the first time, select the table and move it to the second layer. The second layer is the layer button directly to the right of the first layer button.補(bǔ)光和邊緣光，在另一方面，僅僅需要影響葡萄酒瓶本身，不需要影響桌子。這意味著我們將要再次移動桌子，這次移動到層2.跟隨著下面和第一次同樣的步驟，選擇桌子物體并移動到第二層。第二層在第一層按鈕的右邊。Lets take a moment and quickly review what weve done. As of now, we should have: 讓我們看看我們應(yīng)該怎么樣做： Moved everything in our scene, with the exception of the wine bottle, the table underneath the wine bottle, and the camera to the layer directly below the first layer button in the Move to Layer dialog box 移動所有場景的物體。除了葡萄酒瓶，桌子，和相機(jī)到Move to Layer dialog到對話框的第一層。 Moved the table once more from layer one to layer two 移動桌子物體到第二層Turning theory into practice 理論轉(zhuǎn)為實(shí)踐We have a vision for our scene and we know how were going to implement that vision. Now, all thats left to do is to do it. Were going to break this down into smaller stepsthis lighting system is going to become fairly complicated fast, and the last thing we want is to get confused and all turned around. Lets break down the rest of the lighting section of this project into the following steps: 我們的場景有一個(gè)版本并我們知道如何去實(shí)現(xiàn)這個(gè)版本?，F(xiàn)在1. Set up the general rig. This includes lamps for the hanging light sources and the ceiling lights. Were not going to worry about light color at this point. With a light rig this complex, were going to want to make sure first and foremost that the light intensity is balanced well before we start worrying about the details. 建立普通的系統(tǒng)。這包括懸掛的燈光和天花燈?，F(xiàn)在我們不需要擔(dān)心燈光顏色。對于這個(gè)復(fù)雜的燈光系統(tǒng)，在我們開始考慮細(xì)節(jié)前，首先考慮的是燈光強(qiáng)度。2. Set up the 3-Point rig for the wine bottle and table. 為葡萄酒瓶和桌子建立三點(diǎn)燈光系統(tǒng)。3. Set the lamp colors and set the ambient lighting settings, if applicable. 設(shè)立燈光的顏色并設(shè)置環(huán)境光，（ambient lighting）如果有。4. Tweak until satisfied. 細(xì)微調(diào)整直到滿意。Setting up the general rig 建立一般的燈光系統(tǒng)This step is by far the most straightforward step for this project. We are simply going to place lamps directly on top of the already existing three-dimensional models in our scene. 對于這個(gè)項(xiàng)目這個(gè)是最普通的系統(tǒng)。我們直接放置到我們場景的三維模型的頂部。Adding Spot lamps 添加聚光燈To start with, lets set up the lights for the hanging lights on the right side of our composition. Were simply going to create, position, and edit one light, then duplicate it to fit the rest of the lights. 讓我們開始為我們的作品右邊的懸掛燈建立光源。我們只需要簡單的創(chuàng)建第一個(gè)光源，然后復(fù)制到其它的懸掛燈。1. Change into the Top view and make sure youre in wireframe mode by pressing the Z-hotkey. 切換到Top視圖并按Z鍵確保為線框模式。2. Add a Spot lamp by selecting Add | Lamp | Spot. 通過選擇Add | Lamp | Spot添加一個(gè)聚光燈。3. Using the G-hotkey, position it so its directly in the middle of the lampshade of the hanging light closest to the camera. Refer to the following image for help:使用G鍵，放置它到懸掛燈的中間。參考如下圖像：4. Change into either the front or right view and adjust the lamp so that its positioned at the top of the shade, right below the support, as shown in the following screenshot:切換到前視圖或右視圖校正讓它到燈的中心，如下圖所示：Before we continue, make sure that this lamp is on the same layer as the hanging lamps are. This would be the layer found directly below the first layer in the Move to Layer dialog box. If its not already on the right layer, move it using the M-hotkey. 在繼續(xù)下一步前，確保這個(gè)燈光和懸掛燈模型在同一個(gè)層。這個(gè)層在Move to Layer對話框的第一層的下面。如果不是在右邊的層，可以使用M鍵移動到那。Now we need to adjust some lamp settings to better fit our light source. The first thing we need to change is the cone angle of our Spot lamp. Take a look at any real-life lamps that have shades similar to this onethe light follows the shape of the lampshade. This effect is most noticeable when a lamp is placed next to a flat surface, such as a wall.現(xiàn)在我們需要調(diào)整一些燈光設(shè)置更好的適合我們的光源。首先需要的是改變我們的聚光燈的圓錐（cone angle）角度?？纯凑鎸?shí)的燈光的遮擋是相似這個(gè)的燈光沿著燈光模型遮擋的外形。這個(gè)效果當(dāng)燈光在一個(gè)平的表面附近特別明顯，如一個(gè)墻面。To change this setting in Blender, make sure our lamp is selected and go to the Light menu.要在Blender改變這些設(shè)置，確保我們的燈光被選項(xiàng)并到燈光（Light）菜單。Under the Spot Shape settings, theres a parameter called Size. This controls the angle of the cone, which is set to 45 degrees, by default. Adjust this setting until the edges of the cone run parallel with the edges of the lampshade. It should look similar to the following image:在Spot Shape下，有一個(gè)叫Size的參數(shù)。這是一個(gè)設(shè)置圓錐角度的參數(shù)，默認(rèn)是45度。調(diào)整圓錐角度直到到燈罩的邊緣?？雌饋眍愃埔韵聢D像：The angle of the cone in the image above is set to 102 degrees, but it may vary slightly, depending on where exactly the lamp is placed.上面的圖像的圓錐角度大約是102度，但它很精確的對于燈光。The next step is to change the Blend settingthis setting tells Blender how soft or hard to render the edges of the light on a surface. Our goal is to create a nice, soft edge. For now, set the value at 0.4. This should create a nice enough effect for what were looking for. We also want to change the Energy setting to 0.7. Remember, earlier we decided to incorporate a darker background to make our wine bottle in the foreground pop forward.下一步是改變Blend設(shè)置這個(gè)設(shè)置告訴Blender在一個(gè)表面光源的邊緣有多硬或多軟。我們的目標(biāo)是創(chuàng)建一個(gè)很好的軟邊緣?，F(xiàn)在，設(shè)置值為0.4.這足夠創(chuàng)建一個(gè)很好的效果。我們也改變Energy值為0.7。記得前面我們決定我們需要一個(gè)暗暗的背景來突出我們的葡萄酒瓶。The final step is to adjust the Shadow settings. By default, Blender renders ray-traced shadows with Spot lamps, but we want to change this to buffer shadows. Because the area of our scene that will be lit by this lamp will be in the background, we dont have to worry about getting high-quality results, so we can get away with the buffer shadow algorithm. This will also cut down on our render time, because Blender wont have to make all of the mathematically meticulous calculations that come with the ray-tracing algorithm. Under the Sample Buffers setting, perform the following: 最后一步是調(diào)整陰影（Shadow）設(shè)置。Blender默認(rèn)的是聚光燈的光線追蹤（ray-traced）陰影，但我們想要改變?yōu)閎uffer陰影。我們將通過這燈照明我們場景的背景區(qū)域，我們不擔(dān)心是否有高質(zhì)量的結(jié)果，所以我們可以使用buffer陰影來計(jì)算。這也將節(jié)省我們的渲染時(shí)間，因?yàn)锽lender 不用對所有的物體都使用光線追蹤（ray-traced）進(jìn)行精確的計(jì)算。在Sample Buffers設(shè)置下，完成下列操作：1. Set the number of sample buffers to 4. 設(shè)置采樣緩存（sample buffers）數(shù)量為4.2. Set the Size to 1024. 設(shè)置Size 為1024。3. Set the Samples to 5. 設(shè)置Samples為5.The last step is to select the This Layer Only option under the Shadow settings. This step is the keyif we dont choose this step, our lamp wont be linked to the layer. Although that isnt a huge problem right now, it will be if we dont set it up right with our 3-Point light rig, later in this chapter. 最后一步是勾選Shadow設(shè)置下的This Layer Only選項(xiàng)。這是很關(guān)鍵的如果我們不勾選它，我們的燈光將不會連接到層。雖然現(xiàn)在這不是很大的問題，如果我們不在稍后的這章建立三點(diǎn)燈光系統(tǒng)的話。Now that were finished customizing our first light, we can duplicate it to fit the remaining hanging light fixtures. To do so, follow these steps: 現(xiàn)在我們完成了第一個(gè)定制的燈光，我們可以復(fù)制給其它的懸掛燈。要這樣做，跟隨下列步驟：1. Select the Spot lamp. 現(xiàn)在聚光燈。2. Duplicate it by pressing the Shift + D-hotkey and transforming it along the x-axis until it lines up with the next lamp object. Your scene, from the front, should now look similar to the following screenshot: 按住Shift + D鍵并沿著X軸移動直到它對齊到下一個(gè)燈光物體。你的場景的前視圖看起來應(yīng)該是這樣的：3. Repeat steps 1 and 2 until the entire row of hanging lamps is set up. Once thats done, we can move on to the other set of lights! 重復(fù)步驟1和步驟2直到建立所有的懸掛燈光。完成后，我們將去設(shè)置其它的燈光!Lets take a look at how our scene looks so far. With only the Spot lamps lighting the scene, we get an effect similar to the following render: 讓我們看看我們的場景現(xiàn)在是怎么樣的。對于只有聚光燈的場景，我們得到以下的渲染：Before we create our next lamp, we need to move the lampshades to another layer. With the lampshade selected (named lamp_shade), move it using the M-hotkey to the layer next to the layer its currently on. 在我們開始創(chuàng)建下一個(gè)燈光前，我們需要移動我們的燈罩到另外的層。使用lampshade選擇(名字叫l(wèi)amp_shade),使用M鍵移動到當(dāng)前層的下一層。With the new layer selected, add a new Point lamp. This lamp will light the interior of our lampshade, giving it the impression that the light bulb is really affecting it. Move the new lamp using the G-hotkey so its in the same place as our light bulb object. Also, change the color of this lamp to match the yellow hue Spot lamps we created earlier. 在新的選擇層，添加一個(gè)點(diǎn)光源。這個(gè)燈光將照明我們的燈光內(nèi)部，給它一個(gè)燈泡的效果。使用G鍵移動新創(chuàng)建的燈光讓它和燈泡物體在同一個(gè)地方。改變這個(gè)燈光的顏色以匹配我們前面創(chuàng)建的聚光燈。Before we render, we have to do three things. The first is link the lamp to the layer. 在我們渲染前，我們有三件事情要做，首先是鏈接燈光到層。To do this: 如下：1. Without the lamp selected, select the This Layer Only option under the Lamp settings. 選擇燈光物體，勾選Lamp設(shè)置下的This Layer Only選選項(xiàng)。2. Next, turn on shadows by selecting Ray Shadow underneath the Shadow settings. The default values are fine.接下來通過點(diǎn)擊Shadow下的Ray Shadow按鈕打開。默認(rèn)的設(shè)置是已經(jīng)很好。3. Like we did with the Spot lamp, duplicate our new lamp and move it so it fits under every hanging lamp.像我們的聚光燈（Spot），復(fù)制我們新的燈光并移動它們到每個(gè)懸掛燈的下面。Now lets render out our image!現(xiàn)在讓我們渲染我們的圖像！Its a good start! Lets add some more lamps!這是一個(gè)很好的開始！讓我們添加更多的燈光！Setting up Area lamps 建立區(qū)域燈光The second set of lights can be approached in the same way the first set was. The biggest difference between the two is the type of lamp used. Because the lights above the booths are held in rectangular casings, the best lamp we can use to simulate this is an Area lamp. This can be done by performing the following steps: 第二組燈光可以使用和第一組相同的設(shè)置方法。最大的差別是兩種燈光類型的用途。因?yàn)橐樟恋男》块g上面是長方形，所以最好的使用區(qū)域燈（Area lamp）來模擬。可以通過如下步驟完成：1. Change into the Top view. 切換到頂視圖。2. Add an Area lamp by selecting Add | Lamp | Area.通過Add | Lamp | Area菜單添加一個(gè)區(qū)域燈。3. Position it using the G-hotkey so its placed directly above the booth farthest right. Also be sure to change into the Front or Right view to make sure the lamp is facing downward and positioned as close to the ceiling as possible. Refer to the following image for help:使用G鍵移動到小房間的最右邊。切換到前視圖或右視圖確保燈光是朝下并盡可能接近天花。參考以下圖像：Although there isnt a table at the far right booth, the viewer assumes that our scene expands beyond the frame of our image. This means that we need to create the illusion that our scene continues beyond our render by adding this lamp.雖然這沒有一張桌子在小房間的右邊，觀察假定我們的場景越出我們的圖像范圍。這意味著我們需要通過添加這個(gè)燈光來創(chuàng)建我們的場景繼續(xù)在我們的渲染范圍外的假象。As with our Spot lamp, were going to duplicate our Area lamp so we can preserve our settingsthis way, we dont need to repeatedly set the same settings. Before we do this, though, make sure its on the same layer as our Spot lamps by selecting the lamp and moving it to the proper layer using the M-hotkey. Now to start, we need to change the shape of the lamp to better reflect the shape of the actual light model. With the Area lamp selected, go to the Lights menu and take a look at the Area Shape settings. 像我們的聚光燈那樣，我們將復(fù)制我們的區(qū)域燈并可以保持相同的設(shè)置，我們不需要擔(dān)心同樣的設(shè)置。在我們開始前，我們可以和我們的聚光燈的移動層的方法按M鍵移動區(qū)域燈到合適的層。開始，我們需要改變燈光的形狀適合實(shí)際。選擇區(qū)域燈光，到Lights菜單并看看Area Shape設(shè)置。By default, Blender creates a square Area lamp, but were going to want a rectangular one. To change this: 默認(rèn)的，Blender創(chuàng)建一個(gè)正方形的燈，但我們想要一個(gè)矩形的燈光。