通過vray渲染器來制作靜物的教程

原教學(xué)出自CGArena網(wǎng)站，原始鏈接如下：

http://www.cgarena.com/freestuff/tut…ing/index.html

作者: Géza Kádas, Budapest

網(wǎng)站：www.techtron.extra.hu

Studio Lighting in Vray

如何使用Vray渲染靜幀

In this tutorial i will tell you the method of studio lighting. For the rendering i used Vray 1.5rc3, the latest version of the program. This famous chair called “Corbusier” was modeled in 3ds max 9. With the knowledge of this tutorial you will be able to present your models in a more ambitious way than before…

在這個教學(xué)里面我將告訴你影樓燈光的制作方法。使用的是Vray 1.5rc3進行渲染。這把著名的椅子叫做”Corbusier”，是在3ds max 9中創(chuàng)建的。使用本教學(xué)所講的方法將會使你更能出色的展示你的模型。

The main parts of the tutorial are :

本教學(xué)主要包括以下內(nèi)容：

* Making the environment

* 環(huán)境的創(chuàng)建

* Placing the lights

* 燈光的布置

* Setting up Vray for tests

* Vray的測試設(shè)置

* Shaders

* 材質(zhì)制作

* Setting up Vray for final rendering

* Vray的最終渲染設(shè)置

* Postwork in Photoshop

* Photoshop的后處理

Making The Environment

環(huán)境的創(chuàng)建

The environment is pretty much simple. Place a plane under the model and set 3 for the Length segments and set 2 for the Width segments.Convert it to editable poly with right click on the plane and choosing “convert to:”. The next step is selecting the two edges behind the chair and pull them up while pressing the shift button… With this way create a shape around the model like in the third picture.

環(huán)境的創(chuàng)建非常簡單。在模型下面放置一個平面，設(shè)置長度的分段數(shù)為3，寬度的分段數(shù)為2，.然后轉(zhuǎn)換為可編輯多邊形。接下來的步驟是選擇椅子背后的兩條邊，按住shift鍵向上擠出新的面，使用這種方法創(chuàng)建出如第三張圖所示的環(huán)繞模型的

We will use a Turbosmooth modofier on the plane, but to controll the way of smoothing we have to chamfer a few edges before.

對剛創(chuàng)建的平面使用Turbosmooth修改器，但在光滑前我們必須對幾條邊進行chamfer處理。

Now we are able to use the turbosmooth with 2 Iterations.

現(xiàn)在我們可以使用Turbosmooth修改器了，迭代次數(shù)設(shè)置為2.

Placing the Lights 燈光的布置

This topic is the heart of the studio lighting. We will use 3 vray lights with different strength,postion and color. This three attribute will determine the mood and the individuality of youre render. So place a vray light from left view, with the given settings.

這部分內(nèi)容是studio lighting的核心部分，我們將使用三盞不同強度、不同位置和不同顏色的vray燈光。這三個屬性將決定你的渲染結(jié)果的整體基調(diào)和特性。所以首先在左邊放置一盞vray燈光，設(shè)置如下。

 Now change to top view ,copy the light and mirror it to the X axle. Place it to the right side of the plane and use the given settings. The third light will be placed later, after the test renderings.

現(xiàn)在切換到頂視圖，復(fù)制剛才的燈光然后在X方向上鏡像。然后把這盞復(fù)制出來的燈光放置左面，設(shè)置如下所示。第三盞燈光將在后面創(chuàng)建，在測試完成以后。

Create a Target Camera from top view with 35mm lens, and set it up as you see.

在頂視圖創(chuàng)建一個35mm lens得目標(biāo)攝像機，位置如下所示。

All right, choose vray as youre primary renderer. Make a vray material with a light grey diffuse color, R:170/G:170/B:170. Put this material to the “override mtl” slot in the Global Switches tab.

好了，現(xiàn)在更改渲染器為vray渲染器，創(chuàng)建一個vray材質(zhì)，diffuse color為亮灰色R:170/G:170/B:170.然后在全局開關(guān)卷展欄中把該材質(zhì)鏈接到”override mtl”后面的按鈕上。

Now all the objects in the scene will have this material, so this function is great to test lighting with a clay render. Later we will turn this function off. Hit F9 and lets see what we got here.

現(xiàn)在，場景里面所有的物體都會使用這個材質(zhì)，這個功能對于燈光測試是非常好用。后面我們會把這個功能關(guān)掉，執(zhí)行F9看看渲染結(jié)果。

* So this is what we have without any settings. No illumination,or any kind of sampling except the standard one. Now we need to set up vray for test renderings. It is time to move to the next topic.

*以上就是所得的結(jié)果，沒有其他的設(shè)置，只使用燈光的照明沒有使用間接照明，現(xiàn)在我們需要去設(shè)置vray進行測試渲染。

*Setting up Vray for Tests Vray的測試設(shè)置

To test the illumination in the scene we need to set up vray with low values. These are only tests ,so we only want a quick feedback from the lighting. First of all change the image aspect ratio to 1.8 in the Common tab. Go to camera view and turn on the “Safe Frame” option. Safe Frame will help you to place your camera to the right position and it is also helps to notice unwanted parts in the view.

為了測試場景的照明我們需要把Vray得參數(shù)設(shè)置的較低。因為這僅僅是測試，所以我們只需要快速的得到照明的反饋即可。首先在公用標(biāo)簽下改變image aspect ratio為1.8. 到攝像機視圖中打開安全框，安全框可以幫助你把攝像機的位置放好同時也可以幫助你發(fā)現(xiàn)視圖中不需要的部分。

Now here comes the capital part of the Renderer tab settings.

接下來是渲染設(shè)置面板的主要參數(shù)設(shè)置。

這是是對測試設(shè)置的簡單介紹：

* Default lights: turn it off ,we do not want any light, except the vray ones.

* 默認燈光：關(guān)掉。我們只想使用vray的燈光而不像使用其他的。

* Adaptive QMC: A faster image sampling method than Adaptive subdivision.

* 自適應(yīng)準(zhǔn)蒙特卡洛：比自適應(yīng)細分更快的圖像采樣方法。

* Mitchell-Netravali: With this antialiasing filter edges will be sharp but not crisp.

* Mitchell-Netravali:：使用這種抗鋸齒過濾在邊緣的地方會更加的清晰并且鋸齒較少。

* Irradiance map + Light cache: the mostly used GI combination.

* 發(fā)光貼圖+燈光緩存：GI的最常見的組合。

* HSph subdiv: (GI samples) lower it to speed up the rendering process.

* 半球細分：（GI采樣）較少的值會使速度加快。

* Show calc phase: The rendering process will be visualized, so if are not happy with the effect you don’t have to wait until the effective rendering.

* 顯示計算過程：想染過程將會可見，所以如果你不滿意結(jié)果可以馬上停止而不用等到渲染結(jié)束。

* Subdivision: The subdiv. of lightcache controls the number of traced paths… The actual number of the traced paths is the square of the adjusted number.So with 500subdiv. 250.000 paths will be traced.

* 細分：燈光緩存的細分控制光線的數(shù)量，實際的光想追蹤路徑會是參數(shù)的一半，所以細分值為500，就是說有250條路徑會被追蹤。

* Exponential: With this type of colormapping ,colors will be saturated so you can avoid burnouts on the surfaces.

* 指數(shù)曝光：使用這個類型可以避免曝光過度。

* Dark multiplier: This controls the “Sternth” or the multiplier of dark colors.

* 黑色倍增：這個參數(shù)控制暗色的倍增。

* Render region division: set it to 32×32 ,smaller bucket size less ram will needed with smaller bucket size a faster feedback can be achieved. All right, lets see the render with the mentioned settings.

* 渲染范圍劃分：設(shè)置為32 x32，較小的設(shè)置會降低內(nèi)存的使用，并且加快渲染設(shè)置。好了，讓我們來看看這些設(shè)置的渲染結(jié)果。

It is much better than the first one. The scene is much more brighter, light is smoother and there are no burnouts. Because of the low quality settings there are GI artifacts ,noise and blurry lines. However ,these settings provide us a very efficent way of testing. Lets play with the colors to break the dull feeling of the render. Change the color of the vray light on the right to R:255/G:180/B:80. This warm orange color will take care of the monotonic lighting.

現(xiàn)在比第一張好多了，場景變得更亮了，燈光更加柔和并且沒有曝光過度。由于渲染參數(shù)設(shè)置的比較低，所以GI的雜點比較多，線條也顯得比較臟。不過這個設(shè)置提供了快速的測試反饋，讓我們添加點顏色讓場景更加生動，改變右邊燈光的顏色為R:255/G:180/B:80.這個暖調(diào)的橙色會去掉單調(diào)的色彩。

At this point if you are satisfied with the result you can go to the next step. Creating and understanding shaders is the following topic.

如果此時你對結(jié)果滿意就可以進入下一步了，創(chuàng)建和理解材質(zhì)是接下來的工作。

Shaders材質(zhì)

In this scene i used four or five shaders. Plasctic,Chrome,Leather,White fabric, and the white background of course. Turn off the “override mtl” function in the Global Switches tab. Lets take a quick look at the settings.

在這個場景里面我使用了五個材質(zhì)：塑料、鉻、皮革、白色的布料，當(dāng)然還有白色的背景，在全局開關(guān)卷展欄中關(guān)掉”override mtl”。讓我們來看看這些材質(zhì)的設(shè)置。

Diffuse: This controls the color of the material.

漫反射：控制材質(zhì)的顏色。

Reflect: Pure white means 100%reflections ,black means 0% reflections.

反射：純白表示100%的反射，黑色表示完全沒有反射。

Refl. Glossiness: Controls the blurryness of reflection 1 means perfect mirror-like reflections, lower values produce blurry reflections.

反射模糊：控制反射的模糊程度，1意味著鏡面反射，較低的值產(chǎn)生較模糊的反射。

Subdivision: This controls the quality of glossy reflections, higher values increase rendertime lower values produce noisy effect. For testing /5-8/ final rendering /15-35 or higher if necesarry/.

細分：控制反射模糊質(zhì)量，較高的值會增加渲染時間，較低的值會產(chǎn)生噪點，測試設(shè)置為/5-8/最終渲染設(shè)置為/15-35/

Freshnel reflections: If you check it that means the strength of the reflection will depend on the viewing angle of the surface. In nature water and glass is reflecting in this manner. The strength of the reflection depends on the Freshnel IOR too. All right lets see the shaders in action…

菲涅爾反射：如果開啟這個選項就表示反射的強度將取決于相對于物體表面的視角，在自然界中水和玻璃都有這樣的特性，反射的強度也同時取決于Freshnel IOR的參數(shù)，好了，讓我們來看看這些材質(zhì)的效果。

I am pretty happy with the reflections on the leather material. I only need a little more light from above the chair, so lets put that third vraylight to its place.

我對皮革材質(zhì)的反射效果比較滿意，我只需要在椅子的上面再增加些亮度，所以我們將添加第三盞vray燈光。

It is important to uncheck the “Affect Specular” slot, we don’t want any specular reflection from that light ,only diffuse light.

有一點很重要就是要取消掉“影響高光”的參數(shù)。我們不想這盞燈光產(chǎn)生高光，只影響漫反射即可。

As we can see the bounced light reaches to the bottom of the chair too. Now the lighting and the shaders are finished so lets move on to the next topic. I will discuss the settings of the final rendering.

我們可以看到反彈的燈光也照亮了椅子的底部，現(xiàn)在燈光和材質(zhì)都已經(jīng)設(shè)置好了，讓我們進入下一步，最終渲染設(shè)置。

Setting up Vray for Final Rendering Vray的最終渲染設(shè)置

At this point of the workflow it is very important to find the balance between speed an quality. I will talk about the settings globaly, because some problems can’t be solved with only changing the value of an option. So lets see the Renderer tab in this light

在該流程的這個步驟上對于找到速度和質(zhì)量的平衡點是非常重要的，我將談到全局設(shè)置，因為有些問題不能被解決除非設(shè)置正確，讓我們來看看這些設(shè)置吧。

-Change the resoultion to 900×500 -Set the Adaptive rQMC image samplers min dubdiv to 2.Now thinner lines can be rendered correctly.

改變渲染尺寸為900×500-設(shè)置自適應(yīng)準(zhǔn)蒙特卡洛的最小采樣細分為2.現(xiàn)在細小的線條將會被渲染正確了。

-Change the preset of the Irradiance map to Medium from Low.Set 50 to the HSph subdiv to achive higher quality GI.

改變發(fā)光貼圖的預(yù)設(shè)值為中等。設(shè)置半球細分值為50，這樣可以得到高質(zhì)量的GI效果。

-Use value 1200 for the Light cache subdiv.Change the Sample size to 0,006 ,now small details will be more visible. Use value 1000 to the Pre-filter option to reduce noise.We have a lot of glossi rays so check the “Use light cache for glossi rays” option./it will speed up rendering/ For the Filter use the “None” possibility.

設(shè)置燈光緩存的細分值為1200，改變采樣大小為0. 006，現(xiàn)在較小的細節(jié)將會被渲染出來。Pre-filter的值為1000，這樣可以減少噪點的產(chǎn)生，我們有很多的glossy rays,所以勾選”Use light cache for glossi rays”，過濾設(shè)置為”None”會加速渲染過程。

-At the rQMC sampler use value 0,005 for noise treshold. Set the Global subdivs multiplier to 4 ,it will increase samling quality everywhere in the scene.

在準(zhǔn)蒙特卡洛采樣里設(shè)置噪點閾值為0.005，設(shè)置全局細分倍增為4，這樣將會增加場景里面每一個地方的采樣質(zhì)量。

-You can find the Light properties in System>Lights settings. Changing the diffuse subdivision of the lights wil effect the number of the traced photons.

你可以再System>Lights settings找到燈光屬性面板，改變燈光的漫反射細分將會影響到光子產(chǎn)生的數(shù)量。

-Change all the vraylights subdivison to 15 or 20 to avoid noisy parts.

改變所有燈光的細分值為15或者20以避免噪點的產(chǎn)生。

-Change all the materials subdivs to 20 in the Reflection section. With these settings the rendertime will increase a lot according to test render settings. Now hit F9 and wait until the calculation finishes.

改變所有材質(zhì)的反射細分值為20，以上的設(shè)置將會相對測試渲染增加不少時間，執(zhí)行F9來看看渲染結(jié)果。

This is the final rendering, no noise ,artifacts or any nerve-racking rendering trouble. A picture would not be complete without the postwork so lets move on.

這就是最終渲染結(jié)果，沒有噪點或者亂七八糟的渲染問題，渲染的圖片必須經(jīng)過后處理，所以我們繼續(xù)吧。

Postwork后處理

Launch photoshop, and load in the image. Because of the saturated colors of the exponential colormapping type. We need to add more character to the colors and play with the levels to achieve better contrast. Go to Image>Adjustments>Color balance.

啟動photoshop，導(dǎo)入渲染的圖片，由于使用了指數(shù)曝光方式，所以我們需要為顏色添加更多的個性，使用色階編輯器增加畫面的對比度，執(zhí)行圖像-調(diào)整-色彩平衡

Than Image>Adjustments>Levels

接著圖像-調(diào)整-色階

And here comes the finished picture…

這就是最終結(jié)果。

Congratulations ! you finished the tutorial… I hope you liked it