Arnold渲染器IGA广告毛发制作与渲染

本文是一篇关于Arnold渲染器渲染动画广告片的幕后分解。文章展示了这个短片的头发制作和渲染。

*注：arnold（阿诺德）渲染器是在maya和XSI平台下的最新超级渲染器，目前被广泛的适用于电影渲染中，其最大的特点就是物理算法，计算速度快，效率高，设置简单。

原文地址：http://shedmtl.blogspot.ca/
翻译：zivix（ABOUTCG)

制作过程的视频教学解说：

上一篇制作过程的解析教学：https://www.aboutcg.com/14361.html

完整的视频短片

The IGA campain features anywhere from 3 to 16 characters per spot. All these CG actors need to drop by the virtual hair salon before they are allowed on set. Here’s what happened to Oceane Rabais and Bella Marinada at this stage.

1-We always start with the character design made here at SHED as a reference.

任何地方的IGA运动动画中，都有3-16个角色。所有这些CG演员都需要发型的计算。这就是Oceane Rabais和Bella Marinada的发型教程。
1我们总是先从角色设计作为参考。

2 – We then look up on the internet for a real life reference of what the hairdo could look like. This is only as a reference to capture certain real life details. Since we are going for a Cartoonish look, we are not aiming at reproducing the reference exactly. Of course a picture of a duckface girl is always a plus.
2 -然后我们在互联网上查找现实生活中的参考。这只是为了作为一个参考某些真实的生活的细节。因为是卡通角色，所以也不能完全照搬，当然女孩首先是要苗条。

3 – We proceed to create an emitter fitted to the head from which we emit guide strands with Ice. They get their shape from nurbs surfaces. Those guides are low in number (from 200 to 400), so it’s easy to work with them to groom and later simulate and cache on disk. The idea is to get the shape of the hairstyle and the length. The bright colors are there to help see what’s going on.

3 -我们继续在头部创建发射器使用ICE引导。然后从Nurbs获得模型物体。引导的精度很低从200 到400 ),所以很容易计算。这个想法是为了得到发型的形状和长度。明亮的颜色有帮助看到发生了什么。

4 – Next, we clone theses strands, add an offset to their position and apply a few Ice nodes to further the styling. These nodes generally include randomizing and clumping amongst others. We now have around 90 000 strands and it can go up to 200 000.
4,接下来,我们克隆这些引导，添加一些位置的调整和ice节点来体现发型效果。这些节点一般包括随机化和阻尼效果。我们现在有大约90 000股引导和它能上升到200000。

5 – Then we repeat the process with the eyelashes and the eyebrows. During the whole process the look is tweaked in a fast rendering scene.

5 -然后我们重复这个过程，得到睫毛和眉毛。整个过程中外观是调整在一个快速的渲染场景。

6 – Once happy with the results, we copy the point clouds and emitters to the “render model” where the point clouds will be awaiting an Icecache for the corresponding shot. We use Alembic to transfer animation from rig to render model and the Ice emitters .
6 -一旦结果满意,我们复制点云和发射器的“渲染模式”,点云会等待一个Icec缓存。我们用Alembic传输动画到ice发射器。

7 – Back to the Hair model we convert the guides strands to mesh geometries. We apply syflex cloth simulation operators to these geometries to get ready for shot simulation. We link the guide strands to the syflex mesh so they inherit the simulation.
7 -我们把头发引导转化成模型。再使用syflex布模拟头发动力学。

8 – Next comes shot by shot simulation and Ice caching of the guides strands (hair, lashes, eyebrows and beard if necessary).
8 -接下来模拟和缓存ICE的引导线(头发、睫毛、眉毛和胡子如果必要)。

9 – Before we pass down the simulation caches to the rendering department, we need to do a test render to be sure every frame works and there is no glitch/pop. With final beauty renderings taking sometimes close to 2 hours per frame, it is not a good thing to have to re-render a shot because a hair strand is out of place ! The scene we use renders quickly with no complex shaders and only direct lighting.
9 -在缓存结算渲染之前，我们会做些测试渲染来保证所有东西的没问题。以最后的美丽图片以接近2小时每帧的速度渲染,如果因为头发穿插而重新渲染就太糟糕了，下面就是测试渲染。

10 – Once we are happy with the look of the hair, the movement of the simulation AND most of all once we’ve resolved all the problems, we give the signal to the rendering department. The hair PointClouds are always automatically linked to the appropriate simulation cache for the current shot so all they have to do is “unhide” the corresponding object in their scene and voila !
10 -一旦我们满意，就开始渲染一个单帧来看最终效果。头发的PointClouds结算缓存会自动连接到缓存上，最后即渲染啦不拉不拉。