V-Ray ：DOF與陰影地圖

我總是喜歡在相機(jī)里渲染DOF。我不知道為什么。也許我是一個純粹的人，只是喜歡把事情做好。但也許不是。我喜歡v - ray給我的bokeh和控制我設(shè)置它的參數(shù)。盡管對v - ray的DOF有這樣的愛，但它仍然有一些緩慢和笨拙的調(diào)整。因此，當(dāng)我找到一個節(jié)省時間的解決方案來測試和實(shí)現(xiàn)DOF的相機(jī)時，你可以想象我的快樂。讓我給你介紹一下……

I always prefer rendering DOF in the camera. I don't know why. Maybe I'm a purest and just prefer to get things right up front. But maybe not. I love the bokeh that V-Ray gives me and the control I get over setting its parameters. Despite this love for V-Ray's DOF, it has still always been a bit slow and clunky to adjust. You can imagine therefore my delight when I found a time-saving solution to testing and implementing DOF in-camera. Let me introduce you to it...

What even is DOF?

Good question. It is essentially the distance in front of and behind a specific point which is sharp in the output. We'll call that point the focus point. The size of the area that is sharp as well as the amount of blurriness is dependent on a variety of settings in the camera, which we'll look at in more detail in a minute.

DOF是什么?

好問題。它本質(zhì)上是在一個特定點(diǎn)的前面和后面的距離，在輸出中是銳利的。我們把這個點(diǎn)稱為焦點(diǎn)。這個區(qū)域的大小和模糊度的大小取決于相機(jī)的各種設(shè)置，我們稍后會詳細(xì)討論。

A brief word on DOF

Think about it! Don't overuse it or use it incorrectly. This is partly why I find it best to do it in-camera because then the result is correct. Using DOF is a beautiful artistic tool that enables us to bring in an emotive aspect to our visuals. It also helps us to keep the viewer's focus on those areas that we want. There is therefore great power and opportunity with it. Your best bet would be to get out in the real world with a camera and experiment. Get used to how the settings affect the output and grow in confidence that way.

關(guān)于DOF的簡要說明

想想吧！ 不要過度使用或不正確使用。 這部分是為什么最好在相機(jī)中進(jìn)行操作，因?yàn)榻Y(jié)果是正確的。 使用DOF是一個美麗的藝術(shù)工具，使我們能夠在我們的視覺效果上帶來一個感性的方面。 它也有助于我們保持觀眾關(guān)注我們想要的那些領(lǐng)域。 因此，它有很大的權(quán)力和機(jī)會。你最好的辦法是用相機(jī)和實(shí)驗(yàn)在現(xiàn)實(shí)世界中走出來。熟悉設(shè)置如何影響輸出，并以這種方式增強(qiáng)信心。

Controlling the DOF

As previously mentioned, you can control the DOF with several settings. The 2 main controls we will focus on here are the focal length and the aperture size. In principle, the longer the focal length, the shallower the DOF will be. Obviously a wide angle lens is going to have a wider DOF. In terms of the aperture (f-number or f-stop); basically the smaller it is, the shallower the DOF will be. If you want to make sure that everything is in focus then go for a higher aperture. Please note that these will only affect the DOF if it is switched on in the V-Ray camera.

控制DOF

如前所述，您可以使用幾個設(shè)置來控制DOF。我們要關(guān)注的兩個主要控制是焦距和孔徑大小。原則上，焦距越長，就越淺。顯然廣角鏡頭會有更大的DOF。根據(jù)光圈(f - number或f - stop);基本上它越小，DOF就越淺。如果你想確保一切都集中在焦點(diǎn)上，那就去找一個更高的光圈。請注意，這些只會影響在v - ray相機(jī)中切換的DOF。

Setting up DOF in V-Ray: Part 1

Firstly go into your V-Ray Physical Camera and to the Sampling rollout. Tick the ?depth-of-field' tick box and increase the number of subdivisions for a cleaner, less noisy result. I usually use 8 subdivisions for test renders and then I might raise it to 32 subdivisions for production quality renders. This is a time versus quality thing.

在v - ray中設(shè)置DOF:第1部分

首先進(jìn)入您的V-Ray物理相機(jī)和“采樣”卷展欄。 勾選“場景深度”勾選框，并增加細(xì)分?jǐn)?shù)，以獲得更干凈，噪音更小的結(jié)果。 我通常使用8個分區(qū)進(jìn)行測試渲染，然后我可以將其提升到32個細(xì)分為生產(chǎn)質(zhì)量渲染。 這是一個時間與質(zhì)量的事情。

Setting up DOF in V-Ray: Part 2

Once DOF is activated in the camera, you then need to adjust your settings to tweak the result. I adjust the focal length, f-number and focus distance to get the result I need. The focal length adjusts how wide the viewing angle is. The f-number adjusts the distance that is in focus. And finally, the focus distance adjusts the centre point that is most in focus. I would recommend playing around with these on a simple scene so that you get used to how they affect each other.

在v - ray中設(shè)置DOF:第2部分

一旦DOF被激活，你需要調(diào)整你的設(shè)置來調(diào)整結(jié)果。我調(diào)整焦距、f數(shù)和焦距，以得到我需要的結(jié)果。焦距調(diào)整角度的寬度。f數(shù)調(diào)整了焦距的距離。最后，焦點(diǎn)距離調(diào)整中心點(diǎn)最集中。我建議你在一個簡單的場景中玩這些游戲，這樣你就會習(xí)慣它們是如何互相影響的。

Use the V-Ray Stereoscopic helper

Start by going to the ?Create' menu and the ?Helpers' section. Pick ?VRay' from the dropdown. Then create a ?VRay Stereoscopic' object anywhere in the viewport ? it doesn't matter where. Set the eye distance to 0 because we're not using this helper to create a 3D stereoscopic image where the eyes are separated. Then set the Shademap mode to ?Render shade map' and specify a file for the result to be outputted to. This will ensure that when render is next executed, the shade map will be rendered.

使用V-Ray立體輔助器

開始于“創(chuàng)建”菜單和“助手”部分。 從下拉列表中選擇“VRay”。 然后在視口中的任何地方創(chuàng)建？VRay Stereoscopic？ 在哪里無關(guān)緊要 將眼睛距離設(shè)置為0，因?yàn)槲覀儧]有使用這個幫手來創(chuàng)建一個三維立體圖像，眼睛被分開。 然后將Shademap模式設(shè)置為“Render shade map”，并指定要輸出的結(jié)果的文件。 這將確保在下一次執(zhí)行渲染時，將渲染陰影貼圖。

Render the shade map

Now that your stereoscopic helper is set up, double-check your camera DOF settings are as desired and then hit render. Please note that because you are rendering the shade map, there will be no DOF in the resulting image. Don't worry about this. Just think of this step as a pre-calculation step.

渲染陰影映射

現(xiàn)在你的立體助手已經(jīng)設(shè)置好了，雙擊你的相機(jī)DOF設(shè)置就可以了，然后點(diǎn)擊渲染。請注意，由于您正在呈現(xiàn)色度映射，因此在生成的圖像中將沒有DOF。別擔(dān)心這個。只要把這個步驟看成是預(yù)先計算的步驟。

Switch to using the shade map

With the shade map rendered, select the stereoscopic object and set the ?Shademap mode' to ?Use shademap'. Make sure that the file is the same as the one you've just pre-calculated. With that completed, go back to your camera and hit render again. This will render your final image with the DOF but it'll do it in a much quicker time than ordinarily.

切換到使用陰影地圖

使用陰影映射呈現(xiàn)，選擇立體對象并設(shè)置?Shademap模式”?使用shademap”。確保該文件與剛才計算的文件相同。完成后，回到相機(jī)，再次點(diǎn)擊渲染。這將渲染你最后的圖像和DOF，但是它會比一般的快很多。

Switch to using the shade map

With the shade map rendered, select the stereoscopic object and set the ?Shademap mode' to ?Use shademap'. Make sure that the file is the same as the one you've just pre-calculated. With that completed, go back to your camera and hit render again. This will render your final image with the DOF but it'll do it in a much quicker time than ordinarily.

切換到使用陰影地圖

使用陰影映射呈現(xiàn)，選擇立體對象并設(shè)置?Shademap模式”?使用shademap”。確保該文件與剛才計算的文件相同。完成后，回到相機(jī)，再次點(diǎn)擊渲染。這將渲染你最后的圖像和DOF，但是它會比一般的快很多。

Disadvantages vs advantages

The obvious disadvantage to this technique is the inherent approximation that is included. If you want a perfect, physically accurate result, then you will need to render it straight out of the camera. However, you have the obvious advantage of speed with the shade map technique. You can make adjustments to your lighting for example, and re-render again and again using the shade map. This is a massive time saver, especially during the test render phase.

缺點(diǎn)和優(yōu)點(diǎn)

這種技術(shù)明顯的缺點(diǎn)是包含了固有的近似。如果你想要一個完美的，身體準(zhǔn)確的結(jié)果，那么你需要把它直接渲染出來。但是，您有明顯的優(yōu)勢與樹蔭地圖技術(shù)的速度。例如，你可以對你的照明進(jìn)行調(diào)整，并再次渲染，使用陰影貼圖。這是一個巨大的節(jié)省時間，特別是在測試呈現(xiàn)階段。

Top tip 1: Guide the eye with DOF

One of the best uses for DOF other than for artistic flair is that it is a great tool to guide the viewer's eye to the exact part of the image that you want them to focus on first.

提示：引導(dǎo)眼睛與自由度

除了藝術(shù)天賦之外，DOF的最佳用途之一，它是一個偉大的工具，引導(dǎo)觀眾的眼睛的圖像的確切部分，你希望他們把重點(diǎn)放在第一。