因?yàn)榭吹竭^(guò)WZF大神做的玻璃海馬（大神收下我的膜拜），感覺(jué)十分神奇，開(kāi)始思考渲染方法，因?yàn)椴恢朗遣皇沁@么做的所以先把看到過(guò)的 一篇雙面材質(zhì)的 教程貼一下，教程中的vray貌似是3d版本，但是不管是做 樹(shù)葉還是彩色玻璃應(yīng)該對(duì)大家都有些啟發(fā)。
感謝：翻譯者者奧丁的工作 WZF大神一直以來(lái)的辛苦耕耘和奉獻(xiàn) 原文作者
——————————————————————————————————————————————————————————————————————— How to make leaf materials for 3d trees using the VRay2sidedMtl, in this case a sugar maple (in autumn). The tutorial uses Onyx Tree for the tree generation, but this material technique works just as well with other tree objects with low-poly opacity mapped leaves. 在這篇教程中將教大家如何使用Vray雙面材質(zhì)制作紅楓樹(shù)葉。這篇教程使用Onyx Tree來(lái)生成樹(shù)，當(dāng)然這篇教程用到的技術(shù)同樣適用于用其它方法制作的低分辨率使用透明 貼圖作為樹(shù)葉的 模型。 Exporting from Onyxtree.
導(dǎo)入Onyxtree樹(shù)木模型I went with 4 polygons per leaf so that the leaves aren't just flat. Remember to set the dimensions you want the individual leaves, and change the units when you export. You can also make it export 3 different leaf IDs with varying sizes. I normally export as a .obj file 我設(shè)置每片樹(shù)葉4個(gè)多邊形面，這樣葉子看上去就不會(huì)是平的。不要忘記設(shè)置樹(shù)葉的坐標(biāo)（dimensions）和輸出的尺寸單位?？梢暂敵?個(gè)不同IDs和不同大小的樹(shù)葉，然后輸出為obj格式。 Opacity mapping
透明貼圖 It's important to make sure the opacity map is just pure black or white, with a sharp edge. You should also turn off filtering in the bitmap loader options. 想要透明效果渲染正確并且質(zhì)量高，那么透明貼圖應(yīng)該是純白和純黑，并且保持銳利的編輯。同樣還需要設(shè)置bitmap的過(guò)濾方式（filtering）為Nome The opacity map applied to a grey material in 3ds Max and assigned to the leaves. 默認(rèn)材質(zhì)球連接上透明貼圖后的楓葉效果 VRay2sidedMtl
Vray雙面材質(zhì) V-Ray's 2 sided material works best with geometry that has no thickness, which is what onyxtree outputs. It is a very quick way of generating a SSS (sub-surface scattering, think candle wax, skin, milk etc) type look. The image below is rendered using a VRay2sidedMtl on all leaves with grey submaterials and a hand drawn image for the vein skeleton. Vray雙面材質(zhì)在onyxtree 軟件輸出的無(wú)厚度模型上（沒(méi)有擠壓出厚度的多邊形面）效果非常棒。用這種方法可以快速生成SSS效果的樹(shù)葉。下圖就是使用Vray雙面材質(zhì)并連接一個(gè)樹(shù)葉支脈紋理圖片渲染出來(lái)的。 Front material 正面材質(zhì) The front side material is a basic vraymaterial with a diffuse map and a reflection map. The color correction map is to produce slightly different hues of leaf for each of the 3 sub leaf types (you should have got a mult-subobject material when you imported the .obj file). I usually make the first leaf and then copy and paste it to the 2nd and 3rd and just change the hue value slightly. The reflection map is a b&w copy of the diffuse map with levels adjusted to make it more contrasty. 楓葉正面材質(zhì)使用基本vray材質(zhì)連接一張diffuse貼圖和一張反射貼圖表現(xiàn)的。連接在Diffuse通道上面的色彩校正貼圖(color correction map)對(duì)3個(gè)不同類(lèi)型的楓葉設(shè)置稍微不同的色相（hues）值。我一般喜歡先制作好第一個(gè)葉子，然后復(fù)制粘貼出其它的葉子，每個(gè)葉子我只是稍微調(diào)節(jié)Diffuse通道的色相（hues）值。楓葉的反射貼圖是Diffuse貼圖通過(guò)去色和增加對(duì)比度制作出來(lái)的。 Render showing front leaf material on both sides with no transparency. 無(wú)半透明效果下的雙面材質(zhì)渲染效果 Back material 背面材質(zhì) The back material is a copy of the front material but with a different diffuse bitmap and no reflection. Note that I overlaid the veins skeleton jpg on top in photoshop as well. (without it, the veins looked too light when viewed from the underside as they took 100% of the lighter back material) 背面材質(zhì)是正面材質(zhì)的拷貝，唯一不同的地方就是使用了不同的diffuse貼圖以及沒(méi)有用反射貼圖。我在Photoshop中將正面的顏色貼圖疊加上樹(shù)葉經(jīng)脈紋理。(without it, the veins looked too light when viewed from the underside as they took 100% of the lighter back material) （如果沒(méi)有這一步的話(huà)，假使我們使用了較亮的背面材質(zhì)，那么從背光面上看，我們的葉脈會(huì)過(guò)亮。） Render showing 2sided material with correct front/back materials but no transparency. 無(wú)半透明效果下色彩校正后的正面/背面材質(zhì)渲染效果 Finished result 最終渲染效果 | 
/1 
QQ好友和群
