【Blender】CGI(Computer-generated imagery)基础原理、拓扑布线原理-学习笔记
- 教程源自视频:【Blender开源字幕组】CGI基础原理(学习3D之前先学习一下原理吧)
- 原英文原网址 guerrillacg
- 同步到语雀 CGI(Computer-generated imagery)基础原理 笔记
¶P1 几何体属性/多边形是什么
1 | 了解三角形以及它是如何创建复杂三维模型的 |
- 三角形永远是平面flat
- 法线/normal:多边形都具有一个法线,也就是面朝向,电脑可以通过法向来计算多边形着色
- 法线可以是单面或者双面的,如果是单面的,则无法从背面看到多边形
- 因为多边形没有厚度,所以无法从侧面看到多边形
¶P2 大于3条边的多边形 Multi Sided and Intersecting Polygons
1 | 了解多边形并不具备真实物体的物理属性; |
- tri是三角形;quad是四边形; n-gon 大于4边以上的多边形
- non-planar非平面:下拉圆面的一个点,就会变成非平面
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625995977345-23e82df5-1766-44a3-9e63-5bee960f6cc5.png#clientId=ud7a02ddf-68cd-4&from=paste&height=143&id=u65f0edea&margin=%5Bobject%20Object%5D&name=image.png)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625996005790-5628ea6d-0366-44ff-90f4-ae9b9cf56cf4.png)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625995991329-a67f1728-d9e5-4164-aebd-1d07aa7a2b44.png)
- 手动在非平面多边形上切一条边,避免电脑随机分割多边形
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625996203327-515097cd-d8db-4d4c-9ee0-f06152a31443.png#clientId=ud7a02ddf-68cd-4&from=paste&height=130&id=u561a8c54&margin=%5Bobject%20Object%5D&name=image.png&originHeight=356&originWidth=862&originalType=binary&ratio=1&size=361763&status=done&style=none&taskId=u046ac1d5-63e2-4cb0-965f-bb4bd1cb8a7&width=314.9942932128906)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625996206324-7008b36a-48e0-4840-85b8-58a92f9c1e84.png#clientId=ud7a02ddf-68cd-4&from=paste&height=131&id=ua1d9f994&margin=%5Bobject%20Object%5D&name=image.png&originHeight=328&originWidth=879&originalType=binary&ratio=1&size=191497&status=done&style=none&taskId=uabb23020-83e0-4ed4-98ee-2f6d55649e0&width=351.4886169433594)
¶Why use quads?
- 四边形也可以变成 non-planar
- 细分通常需要四边形才可以正常使用
¶Computer Games and Triangles
- 因为性能限制,所以游戏通常用三角形网格、
- 需要告诉电脑如何划分网格,否则会出现折痕等,此时可以通过调整网格布线解决,比如:
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625996514874-9f5cb073-6608-4d97-96b4-7e10b8b16b00.png#clientId=ud7a02ddf-68cd-4&from=paste&height=138&id=u6602fb8a&margin=%5Bobject%20Object%5D&name=image.png&originHeight=476&originWidth=535&originalType=binary&ratio=1&size=413112&status=done&style=none&taskId=u0d349bae-c228-4c34-aee3-712e3ce381a&width=155.4971466064453)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625996517885-c7ab9a04-6799-4c98-8f64-2387e78f12ea.png#clientId=ud7a02ddf-68cd-4&from=paste&height=138&id=ue421ee2e&margin=%5Bobject%20Object%5D&name=image.png&originHeight=481&originWidth=650&originalType=binary&ratio=1&size=391843&status=done&style=none&taskId=uceb2dfa9-7bfa-453b-a78b-ad6a4d6bc82&width=186.97726440429688)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625996544243-6e298ac9-7fb4-46fc-8195-933d857a80c8.png#clientId=ud7a02ddf-68cd-4&from=paste&height=136&id=u3d7be3ab&margin=%5Bobject%20Object%5D&name=image.png&originHeight=438&originWidth=568&originalType=binary&ratio=1&size=396503&status=done&style=none&taskId=uc47eecf9-f17e-4a3c-8fa6-5d03fa70595&width=175.98863220214844)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625996546317-eec62979-9f63-42a6-b5d2-d6bdd5fcbf44.png#clientId=ud7a02ddf-68cd-4&from=paste&height=137&id=ucdcf9d6b&margin=%5Bobject%20Object%5D&name=image.png&originHeight=370&originWidth=550&originalType=binary&ratio=1&size=350226&status=done&style=none&taskId=uafcadf8d-01ac-4223-b04e-e0f2a0e6f9c&width=203)
¶Intersecting Polygons 相交多边形
- 因为多边形没有物理属性,所以它们可以相交甚至相互穿过。(我们可以利用这一属性建模,类似布尔)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625996737178-b5475d81-23d3-4643-8fdf-474719080d8d.png#clientId=ud7a02ddf-68cd-4&from=paste&height=166&id=u078eaf01&margin=%5Bobject%20Object%5D&name=image.png&originHeight=522&originWidth=617&originalType=binary&ratio=1&size=370945&status=done&style=none&taskId=ua8382767-00ef-4dbe-8961-a9da68a0110&width=196.48863220214844)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625996779708-abde1a92-4d06-4f27-9731-51e6b5f39f61.png#clientId=ud7a02ddf-68cd-4&from=paste&height=164&id=u919cc8e4&margin=%5Bobject%20Object%5D&name=image.png&originHeight=430&originWidth=916&originalType=binary&ratio=1&size=363778&status=done&style=none&taskId=u201476a6-96f3-428b-a5e8-fe908ef8446&width=348.9801025390625)
¶P3 物体 Object
1 | 了解物体属性,包括pivot point枢轴点(轴心、原点) |
- 物体:指一组共享变换旋转缩放等信息的多边形集合
- 物体属性:pivot point, rotation, translation, scale
-
缩放2,表示放大200%
-
¶Objects can be any combination of polygons
- 注意:多边形并没有相连接
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625997604217-45f9327f-8e49-4c19-b03c-7d41b9eb9a5a.png#clientId=ud7a02ddf-68cd-4&from=paste&height=184&id=u73d4340e&margin=%5Bobject%20Object%5D&name=image.png&originHeight=501&originWidth=699&originalType=binary&ratio=1&size=190895&status=done&style=none&taskId=u6d336104-1f35-4469-8959-4d1335a5497&width=256.4886169433594)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625997584170-0d5613c6-18af-4ec5-9736-b3fb2ffbecd5.png#clientId=ud7a02ddf-68cd-4&from=paste&height=184&id=u0091a13d&margin=%5Bobject%20Object%5D&name=image.png&originHeight=489&originWidth=741&originalType=binary&ratio=1&size=221517&status=done&style=none&taskId=u17ce64df-f5e0-4acf-ba63-1ae6ba6bf4d&width=279.4829406738281)
¶Many objects can form an object or model
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625997739946-e56c53df-28ca-45fe-a9f5-b965882bd914.png#clientId=ud7a02ddf-68cd-4&from=paste&height=175&id=ua92228df&margin=%5Bobject%20Object%5D&name=image.png&originHeight=486&originWidth=733&originalType=binary&ratio=1&size=300157&status=done&style=none&taskId=u81fb9123-26a9-47b6-bd52-62bce0e1d6c&width=263.491455078125)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625997743634-355108ae-fe92-4191-8b15-f2a1db8af164.png#clientId=ud7a02ddf-68cd-4&from=paste&height=177&id=ud2910b76&margin=%5Bobject%20Object%5D&name=image.png&originHeight=493&originWidth=707&originalType=binary&ratio=1&size=483620&status=done&style=none&taskId=u4070954a-634f-4bc7-9548-64221d0e6d2&width=254.49429321289062)
¶P4 平滑着色Smooth Shading
1 | 了解“平滑着色”是如何柔化多边形上的折痕的 |
¶Smooth And Hard Edges
- 平直着色
=》 平滑着色
- 可通过“标记为锐边”选择平滑着色的区域
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625998390855-cf4cb5de-863e-4a40-b344-d960d7e74a46.png#clientId=ud7a02ddf-68cd-4&from=paste&height=174&id=u8098d23b&margin=%5Bobject%20Object%5D&name=image.png&originHeight=424&originWidth=492&originalType=binary&ratio=1&size=256013&status=done&style=none&taskId=uf9162b03-380a-4a9d-a0e8-cb29363a64e&width=201.9857940673828)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625998393537-6c49cf76-1180-47cd-b8fb-266188ad98cd.png#clientId=ud7a02ddf-68cd-4&from=paste&height=172&id=u4c0ceb20&margin=%5Bobject%20Object%5D&name=image.png&originHeight=412&originWidth=531&originalType=binary&ratio=1&size=231408&status=done&style=none&taskId=uca4b1bfc-692b-4e42-9b8e-98b74cfce15&width=221.49716186523438)
- 平滑着色能让我们即使用较少的线段也能产生光滑表面的错觉,带来更轻量的网格和渲染速度
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625998461689-27f6956a-c81a-4e52-9da0-09163d73d9d0.png#clientId=ud7a02ddf-68cd-4&from=paste&height=199&id=u1a4019d7&margin=%5Bobject%20Object%5D&name=image.png&originHeight=484&originWidth=758&originalType=binary&ratio=1&size=321924&status=done&style=none&taskId=uaced573d-6b78-4eae-af43-f075e907592&width=311.991455078125)
¶顶点法线 Vertex Normals
- 多边形拥有面法线和顶点法线,当一个位置有多个多边形顶点时,不同法线间的夹角呈现不同的折痕程度,平滑着色会统一法向,使表面呈现平滑状态。
- 面法线指向多边形面所面对的方向
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625998614522-04fafe40-f9f3-4834-9d86-fadabdc83a60.png#clientId=ud7a02ddf-68cd-4&from=paste&height=183&id=u8c62c1d0&margin=%5Bobject%20Object%5D&name=image.png&originHeight=435&originWidth=662&originalType=binary&ratio=1&size=167171&status=done&style=none&taskId=ue61e02ed-a862-47bb-a86b-4f97be88968&width=278.9942932128906)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625998635448-41632f0e-33b6-4cbc-ba31-c8af9023a37d.png#clientId=ud7a02ddf-68cd-4&from=paste&height=183&id=u8a517cb9&margin=%5Bobject%20Object%5D&name=image.png&originHeight=443&originWidth=656&originalType=binary&ratio=1&size=187087&status=done&style=none&taskId=u0c8a2aba-cf1c-4d89-9751-cba46fadd77&width=270.98577880859375)
- 顶点法线,则是改变多边形上的渐变着色 grandient shading of the polygon;如果改变顶点法线的方向,则该顶点周围的着色将发生变化,从而在表面产生渐变;电脑实际上是在伪造faking 多边形上的渐变
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625998864931-76eff2a4-52d7-4db1-a40c-b0eca6124902.png#clientId=ud7a02ddf-68cd-4&from=paste&height=204&id=ucb430723&margin=%5Bobject%20Object%5D&name=image.png&originHeight=408&originWidth=586&originalType=binary&ratio=1&size=183142&status=done&style=none&taskId=ua3707c00-5c3e-479b-84fd-6952a79c8d9&width=293)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625998873042-529dcda6-8c5d-4414-9fac-fbac08e98a7b.png#clientId=ud7a02ddf-68cd-4&from=paste&height=204&id=u72bc6f17&margin=%5Bobject%20Object%5D&name=image.png&originHeight=408&originWidth=633&originalType=binary&ratio=1&size=212583&status=done&style=none&taskId=u52dc983a-76ee-4e7a-9540-10849ad2ca2&width=316.5)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625998880122-5409cffd-23ec-4d08-9e8b-00b473d05f19.png#clientId=ud7a02ddf-68cd-4&from=paste&height=182&id=u4e54062f&margin=%5Bobject%20Object%5D&name=image.png&originHeight=469&originWidth=792&originalType=binary&ratio=1&size=259902&status=done&style=none&taskId=u647a68b1-0287-408f-ac5a-48afa941f53&width=307.9942932128906)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625998887161-75dbfd62-3795-424e-a374-84db58540ecd.png#clientId=ud7a02ddf-68cd-4&from=paste&height=189&id=u9c917eb0&margin=%5Bobject%20Object%5D&name=image.png&originHeight=468&originWidth=762&originalType=binary&ratio=1&size=277428&status=done&style=none&taskId=u10478b4c-f197-4fd4-8909-6027d377c63&width=306.9942932128906)
- 当折线边的顶点法线重合,多边形的折线边的着色变得完全相同,此时这条折线就变得不可见了
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625999087002-98614b6d-f8af-4a2c-80cd-ea67972af1b3.png#clientId=ud7a02ddf-68cd-4&from=paste&height=182&id=u70883bcf&margin=%5Bobject%20Object%5D&name=image.png&originHeight=483&originWidth=588&originalType=binary&ratio=1&size=189489&status=done&style=none&taskId=ua2a57546-39ee-4d5a-927f-5a922c63b7c&width=220.991455078125)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625999093483-8b29fd6a-6a2a-4566-b111-c1275ca30e7b.png#clientId=ud7a02ddf-68cd-4&from=paste&height=180&id=u9afc62e9&margin=%5Bobject%20Object%5D&name=image.png&originHeight=477&originWidth=699&originalType=binary&ratio=1&size=260430&status=done&style=none&taskId=u101b8cd7-22bd-4c0d-ab6b-29181993790&width=263.4886169433594)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625999096919-399953f4-4b68-4bf6-9d13-02f390caf99e.png#clientId=ud7a02ddf-68cd-4&from=paste&height=185&id=ubd6ec182&margin=%5Bobject%20Object%5D&name=image.png&originHeight=472&originWidth=730&originalType=binary&ratio=1&size=293172&status=done&style=none&taskId=u903a578c-e216-4971-a247-726db8b58ed&width=286)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625999100367-23e6fde8-07e1-4d2d-952d-58ceb25d6724.png#clientId=ud7a02ddf-68cd-4&from=paste&height=185&id=u71a575ea&margin=%5Bobject%20Object%5D&name=image.png&originHeight=488&originWidth=748&originalType=binary&ratio=1&size=303696&status=done&style=none&taskId=u2ad0e6cf-a330-417c-b94c-b00f2991274&width=283.991455078125)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625999101064-8bbe6958-2e6c-47d2-ac83-42a93b7c5da4.png#clientId=ud7a02ddf-68cd-4&from=paste&height=198&id=ua6f9a03f&margin=%5Bobject%20Object%5D&name=image.png&originHeight=476&originWidth=573&originalType=binary&ratio=1&size=228321&status=done&style=none&taskId=ucfe8166d-f5b5-4ca1-86fe-27473a41f4e&width=238.491455078125)
- 更为复杂的平滑着色例子:
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625999312627-776ec0af-a028-456c-896d-b6337168faac.png#clientId=ud7a02ddf-68cd-4&from=paste&height=186&id=u68c9a980&margin=%5Bobject%20Object%5D&name=image.png&originHeight=429&originWidth=661&originalType=binary&ratio=1&size=251640&status=done&style=none&taskId=uaa7fde1f-e28a-43b5-bdb1-6a31baf4add&width=286.4971618652344)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625999313896-c2a5bfb1-16cb-445c-8785-133776583902.png#clientId=ud7a02ddf-68cd-4&from=paste&height=182&id=u023e9c1c&margin=%5Bobject%20Object%5D&name=image.png&originHeight=389&originWidth=638&originalType=binary&ratio=1&size=194089&status=done&style=none&taskId=uc48424dd-9bfc-4ebc-a68f-ea64a3a207a&width=298.9829406738281)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625999328880-b1ff74db-d346-4b3b-b37b-dcebc7f7e0e5.png#clientId=ud7a02ddf-68cd-4&from=paste&height=236&id=ubf543ac1&margin=%5Bobject%20Object%5D&name=image.png&originHeight=471&originWidth=478&originalType=binary&ratio=1&size=188186&status=done&style=none&taskId=ub9ec680d-d79b-48f9-9fe4-a2f6cfd0b9d&width=239)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625999334386-f57789ae-fbfd-433e-bd8c-11afa3f9db10.png#clientId=ud7a02ddf-68cd-4&from=paste&height=227&id=u125ed306&margin=%5Bobject%20Object%5D&name=image.png&originHeight=454&originWidth=494&originalType=binary&ratio=1&size=203338&status=done&style=none&taskId=u0b3272d9-aaf0-4846-98b5-8861c3e1507&width=247)
¶基于角度的平滑着色 Smoothing Based On Angles
- 一般软件允许我们限定平滑的角度(小于这个角度的会执行“平滑着色”)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625999524533-d2b18055-d06d-4341-8eec-7fd06d6bf570.png#clientId=ud7a02ddf-68cd-4&from=paste&height=181&id=u039b77ae&margin=%5Bobject%20Object%5D&name=image.png&originHeight=500&originWidth=640&originalType=binary&ratio=1&size=282686&status=done&style=none&taskId=u247861dc-9f25-4428-99b6-4f9b97aebe8&width=232)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625999530975-4ee1fc46-1ef3-415f-ab58-e0bd2121cd51.png#clientId=ud7a02ddf-68cd-4&from=paste&height=183&id=ue6ce7da6&margin=%5Bobject%20Object%5D&name=image.png&originHeight=483&originWidth=650&originalType=binary&ratio=1&size=261552&status=done&style=none&taskId=u987bf69b-31d3-451b-b15c-114d5dd3632&width=246)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625999533989-4a51888d-09ea-4251-a004-a9f49f171d51.png#clientId=ud7a02ddf-68cd-4&from=paste&height=178&id=ub1685e25&margin=%5Bobject%20Object%5D&name=image.png&originHeight=498&originWidth=657&originalType=binary&ratio=1&size=272343&status=done&style=none&taskId=uc2239118-5e94-4622-bc92-1f38fecd759&width=234.4801025390625)
- 例子:
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625999828713-59db8fce-4ce7-443e-8ed7-1501876862d2.png#clientId=ud7a02ddf-68cd-4&from=paste&height=224&id=u86277668&margin=%5Bobject%20Object%5D&name=image.png&originHeight=448&originWidth=471&originalType=binary&ratio=1&size=144397&status=done&style=none&taskId=u675c99e2-0ed6-478e-a562-1e33fe0dabf&width=235.5)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1625999832084-1019bf58-a4ca-41ce-9934-c3c002a19aed.png#clientId=ud7a02ddf-68cd-4&from=paste&height=230&id=u5942e8f0&margin=%5Bobject%20Object%5D&name=image.png&originHeight=491&originWidth=544&originalType=binary&ratio=1&size=212806&status=done&style=none&taskId=uc480f261-8d92-4a2f-b73f-bebb4568d87&width=254.98861694335938)
¶P5 父子层级 Hierarchies
- 位移,旋转,缩放信息可以由父级物体转递到子级物体。子级物体的变换信息则不会影响父级。
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626001125546-a89e6635-2187-4cb1-81a5-9a588b2a8e0e.png#clientId=ud7a02ddf-68cd-4&from=paste&height=227&id=u9448f7de&margin=%5Bobject%20Object%5D&name=image.png&originHeight=454&originWidth=689&originalType=binary&ratio=1&size=319142&status=done&style=none&taskId=u10f5d0c9-b9bd-4d3b-a53d-148be05e626&width=344.5)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626001139958-f1d9f042-d18a-4f20-b335-3a60db55fc5b.png#clientId=ud7a02ddf-68cd-4&from=paste&height=226&id=u56d7b2c0&margin=%5Bobject%20Object%5D&name=image.png&originHeight=452&originWidth=684&originalType=binary&ratio=1&size=292808&status=done&style=none&taskId=u3c3b1ff5-58ed-456b-99bf-4eb9e30ba4e&width=342)
- 节点网络node network 和 文件夹父子层级是一样的,只是显示方式不同;节点网络中,箭头由父级指向子级
- 文件夹层级通常用于继承父级变换信息的层次结构 ,这里就是"位移,旋转,缩放信息"
- 节点模式层级,还可以继承其他属性,比如约束条件、方程、颜色等
¶用空物体来打组
- 空物体可以是不同形状的,常见 纯轴、立方体……
- 把模型所有组成部分放在一个空物体下,就可以通过选择变换空物体,就可以变换所有组成部分
¶P6 凹凸和置换贴图
1 | 了解置换贴图displacement mapping和凹凸贴图bump是如何工作的 |
- 置换贴图可以改变几何信息,但需要足够细分。bump贴图则只改变视觉效果
- 置换贴图真实改变物体,而bump凹凸贴图则是给人一种几何体被影响的假象
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626003874660-83dc6bc8-a15e-4d60-aef8-5a9eaafb7059.png#clientId=ud7a02ddf-68cd-4&from=paste&height=229&id=u13638ecd&margin=%5Bobject%20Object%5D&name=image.png&originHeight=457&originWidth=599&originalType=binary&ratio=1&size=320122&status=done&style=none&taskId=ubaeb4fa0-2d1c-41f2-ae5b-986d647c8f5&width=299.5)
- 凹凸贴图:优点是less geometry;缺点则是,近距离看物体就没有这种效果了
- 置换贴图:真实改变物体形态,所以我们可以近距离观察物体;缺点就是需要很多geometry
¶贴图
- 置换贴图和凹凸贴图,都是使用灰度贴图
- 贴图中,黑色区域的值为0,表示对物体没有影响;而白色区域值为255,表示对物体有完全的影响;灰色区域的值介于0到255之间。
- 物体受影响程度取决于具体数值。意味着越黑影响越小,越白影响越大
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626004109281-20abe52e-58c2-46dc-a9ab-dbc60c0d5d2e.png#clientId=ud7a02ddf-68cd-4&from=paste&height=228&id=u0a76cde6&margin=%5Bobject%20Object%5D&name=image.png&originHeight=455&originWidth=677&originalType=binary&ratio=1&size=245902&status=done&style=none&taskId=u0e07a292-86a7-4034-aff4-7597c21230f&width=338.5)
¶节省你的时间
- 比如我们要做一个海洋,确实可以用流体模拟功能,但是计算耗时;而直接用置换贴图就可以取得很好的效果
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626004442557-8aed8ff0-a07e-4df1-ae72-199abec2ebae.png#clientId=ud7a02ddf-68cd-4&from=paste&height=174&id=u6423aae7&margin=%5Bobject%20Object%5D&name=image.png&originHeight=347&originWidth=395&originalType=binary&ratio=1&size=162262&status=done&style=none&taskId=u4824889e-f0bb-4a78-8ac5-be685ef95ab&width=197.5)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626004412647-f3fa7580-6dec-408e-80a7-c0d43062a98b.png#clientId=ud7a02ddf-68cd-4&from=paste&height=156&id=u4423adbd&margin=%5Bobject%20Object%5D&name=image.png&originHeight=311&originWidth=703&originalType=binary&ratio=1&size=447404&status=done&style=none&taskId=u53c7e2c0-f250-4865-b3f7-4714cb9bf60&width=351.5)
¶P7 表面细分
1 | 表面细分如何工作 |
¶何为表面细分
- 表面细分:可以将一个低面数的模型平滑成一个高面数的模型;它并不像是“平滑着色”那样,而是真实改变了 模型的几何结构geometry
- 我们把低面数的模型成为“控制罩体 Control cage”;表面细分激活后,我们仍然可以编辑控制罩体的网格
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626004889443-8673554d-124b-44dd-8f97-15bad57e9cd3.png#clientId=ud7a02ddf-68cd-4&from=paste&height=231&id=ue627a94e&margin=%5Bobject%20Object%5D&name=image.png&originHeight=462&originWidth=657&originalType=binary&ratio=1&size=372693&status=done&style=none&taskId=uc4599911-0f02-47b7-a604-cdfb837bca5&width=328.5)
¶细分等级
- 细分会使模型面数增加;每个级别的细分等级都会把面数乘以4倍
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626004982008-0438a944-8f49-4395-a8bb-6d2c1e301643.png#clientId=ud7a02ddf-68cd-4&from=paste&height=157&id=ue4fd7653&margin=%5Bobject%20Object%5D&name=image.png&originHeight=426&originWidth=694&originalType=binary&ratio=1&size=154315&status=done&style=none&taskId=u2e29b147-2031-4f6c-8a32-03d6778f82d&width=255.98861694335938)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626004984790-b51d158c-352f-44f8-8944-7ed74e99204f.png#clientId=ud7a02ddf-68cd-4&from=paste&height=156&id=u8b008f83&margin=%5Bobject%20Object%5D&name=image.png&originHeight=417&originWidth=627&originalType=binary&ratio=1&size=148484&status=done&style=none&taskId=ud102a881-7235-41ca-96d4-64ea0b0c7ff&width=234.49429321289062)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626004995890-5ecea940-62ed-4896-be0a-567666596ca3.png#clientId=ud7a02ddf-68cd-4&from=paste&height=154&id=u1f60eab6&margin=%5Bobject%20Object%5D&name=image.png&originHeight=421&originWidth=636&originalType=binary&ratio=1&size=198276&status=done&style=none&taskId=ue2951e8b-0be0-441e-ba81-d2f9e6a195a&width=231.99147033691406)
- 三维软件允许我们在预览和渲染时,设置独立级别的细分等级;我们可以在预览时候使用低细分等级的,便于更快速地操作,在渲染时候用高细分等级的
- 当细分等级过高时候,肉眼看不出区别,所以不是细分等级越高越好。细分等级越高,模型需要更长时间和系统内存来渲染,比如细分等级4的模型面数是细分等级3的模型的4倍
- 较小或较远的模型细分等级,应该比距离镜头较近的模型的细分等级低;最佳的细分等级需要不断调试才知道
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626005346298-ae093373-8051-4c68-9244-750f3bcf7f06.png#clientId=ud7a02ddf-68cd-4&from=paste&height=273&id=u574def7f&margin=%5Bobject%20Object%5D&name=image.png&originHeight=546&originWidth=743&originalType=binary&ratio=1&size=637837&status=done&style=none&taskId=u9c2b2521-e575-406e-83df-cfa258d91fe&width=371.5)
- 可以用表面细分和平滑着色来创建外观非常平滑的模型
- 平滑着色不会平滑掉你的模型边缘
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626005477086-95762e65-ca92-4f35-937e-f2b43d420578.png#clientId=ud7a02ddf-68cd-4&from=paste&height=192&id=u2458b692&margin=%5Bobject%20Object%5D&name=image.png&originHeight=494&originWidth=615&originalType=binary&ratio=1&size=270479&status=done&style=none&taskId=u208ac533-5cec-4903-9177-1ae0ed6e935&width=238.5)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626005482667-ece7fd67-1be8-415d-b23a-852f1ff57dfa.png#clientId=ud7a02ddf-68cd-4&from=paste&height=191&id=u86a7016d&margin=%5Bobject%20Object%5D&name=image.png&originHeight=452&originWidth=691&originalType=binary&ratio=1&size=332637&status=done&style=none&taskId=ub4ac3102-a4f4-4cb4-84a1-40cef9be173&width=292.4971618652344)
- 如果模型轮廓看起来过于棱角,则需要增加细分等级
¶表面细分是如何工作的
- 大多数三维软件使用近似值法而不是插值法来细分网格,所以细分后的网格不会通过与控制罩体相同的顶点位置
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626005814459-10063495-f367-4061-869f-9718ab4afab5.png#clientId=ud7a02ddf-68cd-4&from=paste&height=214&id=ue42c4163&margin=%5Bobject%20Object%5D&name=image.png&originHeight=427&originWidth=631&originalType=binary&ratio=1&size=147272&status=done&style=none&taskId=ueeaa9dd6-0146-4d86-93a8-7fbbb7fa2f1&width=315.5)
- 当需要锐角时,简单的方法就是将顶点考得更近。而如果需要光滑的表面,那就让顶点间的间隔更大些。因为所有顶点对曲线的形状都具有同等的影响。
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626005867624-cc55b697-1c93-4543-a674-f9be8257e66e.png#clientId=ud7a02ddf-68cd-4&from=paste&height=174&id=uc4c0e02d&margin=%5Bobject%20Object%5D&name=image.png&originHeight=417&originWidth=716&originalType=binary&ratio=1&size=180000&status=done&style=none&taskId=u6384d003-fd86-4275-bbd7-0d1eda0b896&width=298.99713134765625)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626005908676-e04a761e-c03d-4a70-9582-dd4110ac80ce.png#clientId=ud7a02ddf-68cd-4&from=paste&height=178&id=u3dd1964f&margin=%5Bobject%20Object%5D&name=image.png&originHeight=457&originWidth=694&originalType=binary&ratio=1&size=190490&status=done&style=none&taskId=u5cd42899-8100-477c-bd35-8240ff99855&width=270.9886169433594)
¶为什么是四边形
- 做光滑表面最好的方法就是在网格中使用四边面
- 由前面的细分成为平滑曲线可以看出,如果我们创建了一个四边形网格,则样条线就会两两彼此穿插(即每个点连接着四个方向的线段),样条线不断从一个顶点走到下一个顶点,这样模型走向就如我们所料地那样生成了
- 如果我们有一个连接线段多或者少于4个顶点,样条线就会被阻断,我们的网格就可能无法像预期那样平滑了
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626006352821-626ef81d-0198-4ddb-a6ec-04f1d847a111.png#clientId=ud7a02ddf-68cd-4&from=paste&height=174&id=u2b58d36f&margin=%5Bobject%20Object%5D&name=image.png&originHeight=454&originWidth=655&originalType=binary&ratio=1&size=216935&status=done&style=none&taskId=u384eaff1-fdf5-44bd-9db5-3ca5d03b647&width=251.5)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626006395120-756e68dd-c547-4359-b3f7-fc202563afd3.png#clientId=ud7a02ddf-68cd-4&from=paste&height=171&id=u7a9d12fc&margin=%5Bobject%20Object%5D&name=image.png&originHeight=413&originWidth=877&originalType=binary&ratio=1&size=548468&status=done&style=none&taskId=u64fe0559-16e1-4a4a-98a4-9d4ee9ee826&width=362.4942932128906)
- 这种表面细分导致样条线在模型表面流动的概念将引领我们到拓扑的学习中
¶P8 表面细分拓扑 错误(瑕疵)Sub Division Topology Artifacts 【其实也是“布线原理/原则”相关】
1 | 介绍拓扑和造成平滑瑕疵的原因 |
¶拓扑中的四边面和细分曲面 Quads And Sub D Topology
- 三角形和多边形在表面细分时会产生突起。
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626006942376-9676acc5-a980-4931-8d93-db1f58b6fc67.png#clientId=ud7a02ddf-68cd-4&from=paste&height=182&id=u7724aefe&margin=%5Bobject%20Object%5D&name=image.png&originHeight=472&originWidth=614&originalType=binary&ratio=1&size=239599&status=done&style=none&taskId=ube04ac85-7d8a-4284-b8d4-aba88812f19&width=236.9801025390625)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626006842289-f1582d49-2e9a-4753-9d79-e3d69d806fe9.png#clientId=ud7a02ddf-68cd-4&from=paste&height=182&id=u250083f2&margin=%5Bobject%20Object%5D&name=image.png&originHeight=456&originWidth=630&originalType=binary&ratio=1&size=263761&status=done&style=none&taskId=u259d7361-dbed-4a40-b369-b7e46aeb10c&width=250.97726440429688)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626006845919-f1ee6782-fac0-4d64-8779-8f5a3eeb1bc6.png#clientId=ud7a02ddf-68cd-4&from=paste&height=181&id=u3eaedeb7&margin=%5Bobject%20Object%5D&name=image.png&originHeight=465&originWidth=621&originalType=binary&ratio=1&size=226924&status=done&style=none&taskId=u22a5dbc0-1c45-4d98-949b-0c9526f7444&width=241.491455078125)
- 这些错误会随着面角度的减小而减少。所以一个完全平坦的网格也可能会有糟糕的拓扑,但不会看到任何平滑错误
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626006834113-7e8cdeef-43da-4f61-a81a-3621877bb600.png#clientId=ud7a02ddf-68cd-4&from=paste&height=214&id=u146e9fa0&margin=%5Bobject%20Object%5D&name=image.png&originHeight=428&originWidth=589&originalType=binary&ratio=1&size=192480&status=done&style=none&taskId=u7b756765-b4a0-4d8a-94f6-410d3e0c212&width=294.5)
- 有一个方法可以解决平滑错误,就是使用非常密集的网格。虽然密集的网格可以减少平滑错误的面积和强度,但是这不可行,因为密集的网格很难再去进行动画、材质和渲染的操作
¶使用四边面时会产生的错误
- 造成平滑错误的原因,不止是非四边面。因为我们细分任何网格,它都会变成四边面,但同样的平滑错误会继续出现
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626007239026-f9f427e1-9022-444e-9e81-8ba47befff35.png#clientId=ud7a02ddf-68cd-4&from=paste&height=198&id=u39b11817&margin=%5Bobject%20Object%5D&name=image.png&originHeight=445&originWidth=660&originalType=binary&ratio=1&size=272841&status=done&style=none&taskId=u249c2b51-82d3-4cce-aab6-03923fd7a84&width=294)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626007241507-b78e7f4e-40c3-42b2-abd9-46abc9d46bd1.png#clientId=ud7a02ddf-68cd-4&from=paste&height=199&id=u595541ed&margin=%5Bobject%20Object%5D&name=image.png&originHeight=455&originWidth=663&originalType=binary&ratio=1&size=308057&status=done&style=none&taskId=u34371119-ca50-473f-b636-4ef80cea163&width=290.491455078125)
- 其他平滑错误的原因:
- 明显的顶点偏移。造成它们不恰当的凹凸
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626007319711-8a809438-9ab0-45b5-8386-6cf209ee421b.png#clientId=ud7a02ddf-68cd-4&from=paste&height=194&id=u72123cc9&margin=%5Bobject%20Object%5D&name=image.png&originHeight=486&originWidth=636&originalType=binary&ratio=1&size=311027&status=done&style=none&taskId=u668ef5d0-9655-46e1-b123-fee32a2e619&width=253.99716186523438)
- 不均匀的拓扑也会产生错误。这里看到不一致的变长在平滑时出现明显错误,突起可以通过内侧加一条边解决问题 ——》内侧边是创建一个整洁的可控制转角的好方法;内侧边的移动可以让转角从尖锐变得圆滑
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626007441564-1c49920c-fe49-43b3-9d4b-58d519cda94c.png#clientId=ud7a02ddf-68cd-4&from=paste&height=200&id=ua54f6e82&margin=%5Bobject%20Object%5D&name=image.png&originHeight=491&originWidth=686&originalType=binary&ratio=1&size=354476&status=done&style=none&taskId=u7b564d54-7e7e-4e53-8df9-7688199fa2c&width=279.9971618652344)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626007467409-30156c9e-6b97-430d-af6d-9b32781120ad.png#clientId=ud7a02ddf-68cd-4&from=paste&height=204&id=u706ea0c1&margin=%5Bobject%20Object%5D&name=image.png&originHeight=516&originWidth=655&originalType=binary&ratio=1&size=301464&status=done&style=none&taskId=ud0a83e48-35eb-45af-a4fd-37322915df4&width=258.5)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626007540076-371a2833-2dc9-4937-8539-b23388854a0e.png#clientId=ud7a02ddf-68cd-4&from=paste&height=180&id=u44879233&margin=%5Bobject%20Object%5D&name=image.png&originHeight=421&originWidth=598&originalType=binary&ratio=1&size=115035&status=done&style=none&taskId=ufaa361e7-00fa-4778-aa78-e33f1cb5cf7&width=254.991455078125)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626007558358-1da0d6a2-4dd2-4568-bc36-806f1a648855.png#clientId=ud7a02ddf-68cd-4&from=paste&height=181&id=u16e8370a&margin=%5Bobject%20Object%5D&name=image.png&originHeight=439&originWidth=592&originalType=binary&ratio=1&size=113943&status=done&style=none&taskId=ub437f971-616a-4a45-b0fe-3abdb5447f8&width=243.99429321289062)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626007649053-d9856a07-a2ae-48a5-9008-1256e079631a.png#clientId=ud7a02ddf-68cd-4&from=paste&height=190&id=uf857e58f&margin=%5Bobject%20Object%5D&name=image.png&originHeight=505&originWidth=650&originalType=binary&ratio=1&size=278691&status=done&style=none&taskId=ua0fde4c9-2985-4241-a1a1-b1407d4091e&width=243.98294067382812)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626007654279-e919d2bf-00c8-4059-8edc-a0d532fd8cb3.png#clientId=ud7a02ddf-68cd-4&from=paste&height=180&id=u824dc2df&margin=%5Bobject%20Object%5D&name=image.png&originHeight=465&originWidth=677&originalType=binary&ratio=1&size=303164&status=done&style=none&taskId=u268f065f-4eff-448e-866c-0f8832f90e0&width=262.4801025390625)
¶极点 Poles
- 极点就是连接着许多条边的顶点。
- 有时候极点不可避免。但是请记住,组成极点的线段越多,平滑错误越明显。所以尽量减少极点。可以的话,把极点放在平坦或者不明显的地方
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626007838515-efc38c71-cd9f-4367-8d46-5214c1f92517.png#clientId=ud7a02ddf-68cd-4&from=paste&height=191&id=uf94d9930&margin=%5Bobject%20Object%5D&name=image.png&originHeight=460&originWidth=628&originalType=binary&ratio=1&size=282501&status=done&style=none&taskId=ue6b6914c-4f84-40a4-9f13-c588ea6bd88&width=260.991455078125)
¶消除非四边面
- 偶数边:直接连接顶点成四边形。
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626008214569-f7e933c6-639d-464f-b09b-d4df91946273.png#clientId=ud7a02ddf-68cd-4&from=paste&height=157&id=u13a717e7&margin=%5Bobject%20Object%5D&name=image.png&originHeight=419&originWidth=461&originalType=binary&ratio=1&size=137676&status=done&style=none&taskId=u328f34d4-fc6e-4efe-bd7d-d9dd2a96c01&width=172.4971466064453)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626008219866-accb2894-85d5-4059-821c-7a0e35b32788.png#clientId=ud7a02ddf-68cd-4&from=paste&height=157&id=uf10846de&margin=%5Bobject%20Object%5D&name=image.png&originHeight=425&originWidth=436&originalType=binary&ratio=1&size=151993&status=done&style=none&taskId=ud7a84413-db8b-44bf-a7c0-ff868acfda8&width=160.9971466064453)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626008223659-12e7e5e2-b885-412d-981f-01ac8ece695f.png#clientId=ud7a02ddf-68cd-4&from=paste&height=157&id=u990b9e0c&margin=%5Bobject%20Object%5D&name=image.png&originHeight=407&originWidth=447&originalType=binary&ratio=1&size=152183&status=done&style=none&taskId=u5d7d5cf0-36ca-47ec-9f99-69dcab221ee&width=172.4943084716797)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626008224834-76a36842-f151-4a1a-9bca-f8dd77b2652f.png#clientId=ud7a02ddf-68cd-4&from=paste&height=161&id=uf66e7c95&margin=%5Bobject%20Object%5D&name=image.png&originHeight=404&originWidth=444&originalType=binary&ratio=1&size=132049&status=done&style=none&taskId=uf2d4b0a5-8a6a-4a79-ac98-2555b03570f&width=176.98863220214844)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626008226725-17baf926-1d6b-49df-a6d0-1750529ca8f3.png#clientId=ud7a02ddf-68cd-4&from=paste&height=175&id=u1c36afd0&margin=%5Bobject%20Object%5D&name=image.png&originHeight=414&originWidth=441&originalType=binary&ratio=1&size=146014&status=done&style=none&taskId=u02485b5d-be88-4ecf-a0ba-a3c61e017c1&width=186.4971466064453)
- 奇数边:从数学上来讲,要在不生成新的非四边形的情况下去掉非四边形是不可能的。可以通过增加边或者减少边,使两个奇数边的非四边形相互抵消,
- 增加边,连接两个三角形顶点
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626008595656-d032cf50-0398-42fc-a603-49b226810745.png#clientId=ud7a02ddf-68cd-4&from=paste&height=157&id=u37833882&margin=%5Bobject%20Object%5D&name=image.png&originHeight=440&originWidth=609&originalType=binary&ratio=1&size=197045&status=done&style=none&taskId=ub4fdad89-9ad4-4a23-94e5-b0b167b2acf&width=217.48861694335938)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626008720840-81cece77-5e68-42a7-8735-e78be7eac6ff.png#clientId=ud7a02ddf-68cd-4&from=paste&height=155&id=u850fc20b&margin=%5Bobject%20Object%5D&name=image.png&originHeight=479&originWidth=621&originalType=binary&ratio=1&size=203758&status=done&style=none&taskId=u8710fd50-ef0a-4ba8-a54d-1bceac6fd69&width=201.48863220214844)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626008732038-ffd5e8f1-50e8-4348-a940-c06edbb25783.png#clientId=ud7a02ddf-68cd-4&from=paste&height=173&id=uf4a2a168&margin=%5Bobject%20Object%5D&name=image.png&originHeight=470&originWidth=610&originalType=binary&ratio=1&size=196044&status=done&style=none&taskId=ue720cf3b-9344-4eb5-812b-8ac8caa4e7c&width=225)
- 减少边
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626008775563-7898ccb8-3d7d-43f1-a0ad-037a1942ad6f.png#clientId=ud7a02ddf-68cd-4&from=paste&height=187&id=u8b6955d0&margin=%5Bobject%20Object%5D&name=image.png&originHeight=374&originWidth=658&originalType=binary&ratio=1&size=190695&status=done&style=none&taskId=ue61e2e6f-bb9f-412d-b42a-e42fe684202&width=329)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626008784737-f0946a15-bb69-4ba5-98d7-97d86c7c15db.png#clientId=ud7a02ddf-68cd-4&from=paste&height=188&id=ud75a1fe9&margin=%5Bobject%20Object%5D&name=image.png&originHeight=409&originWidth=651&originalType=binary&ratio=1&size=191763&status=done&style=none&taskId=ua36ca005-5be2-4077-a20f-a0a2d1caad5&width=299.4971618652344)
- 偏移边的一端
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626008775563-7898ccb8-3d7d-43f1-a0ad-037a1942ad6f.png#clientId=ud7a02ddf-68cd-4&from=paste&height=141&id=ARdh5&margin=%5Bobject%20Object%5D&name=image.png&originHeight=374&originWidth=658&originalType=binary&ratio=1&size=190695&status=done&style=none&taskId=ue61e2e6f-bb9f-412d-b42a-e42fe684202&width=247.98577880859375)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626008820312-ce008c3e-cbde-4599-8562-66ad09612b3a.png#clientId=ud7a02ddf-68cd-4&from=paste&height=148&id=ubcd02278&margin=%5Bobject%20Object%5D&name=image.png&originHeight=430&originWidth=651&originalType=binary&ratio=1&size=223097&status=done&style=none&taskId=u6c5b6c18-093c-4e23-99ff-5abc1392932&width=224.4801025390625)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626008836993-93b7dd45-ee33-49a9-b535-958ac42cb2ea.png#clientId=ud7a02ddf-68cd-4&from=paste&height=148&id=u3d123269&margin=%5Bobject%20Object%5D&name=image.png&originHeight=421&originWidth=649&originalType=binary&ratio=1&size=211015&status=done&style=none&taskId=u98ef1881-c92c-4118-9284-05a494e8cfe&width=227.47726440429688)
- 也可以在边上增加或者减少一组循环边的做法
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626009017338-03d5bab3-7364-4132-b684-6b2f40037899.png#clientId=ud7a02ddf-68cd-4&from=paste&height=169&id=u4aee6321&margin=%5Bobject%20Object%5D&name=image.png&originHeight=405&originWidth=437&originalType=binary&ratio=1&size=124422&status=done&style=none&taskId=u0494be8b-7605-4803-96aa-114a0862982&width=182.4943084716797)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626009041816-9650f63a-d8ee-4732-94d7-477a82bff35d.png#clientId=ud7a02ddf-68cd-4&from=paste&height=178&id=uddc2432a&margin=%5Bobject%20Object%5D&name=image.png&originHeight=405&originWidth=433&originalType=binary&ratio=1&size=116124&status=done&style=none&taskId=u35cc78e8-1bb4-4b64-ad6f-46fdee4a33b&width=190.49147033691406)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626009063242-a94a6d72-2b17-494f-a96a-3ed1ab77b0a0.png#clientId=ud7a02ddf-68cd-4&from=paste&height=183&id=ua400e050&margin=%5Bobject%20Object%5D&name=image.png&originHeight=400&originWidth=441&originalType=binary&ratio=1&size=128480&status=done&style=none&taskId=u6baf1765-0d52-45a1-a94a-54e54c91c64&width=201.4971466064453)
¶减少不必要的拓扑
- 模型上的密集和疏散部分可能很难结合起来,比如密集的手指部分和疏散的手腕部分。比如人们可能发现自己在诸如腕部之类部分上使用了太多边。
- 一个好的方法是,让边flow back to where they came from(让边哪里来哪里去)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626009433063-45af91a8-250a-4cd6-8707-2ecafb65b755.png#clientId=ud7a02ddf-68cd-4&from=paste&height=240&id=u1e76c81a&margin=%5Bobject%20Object%5D&name=image.png&originHeight=518&originWidth=463&originalType=binary&ratio=1&size=330524&status=done&style=none&taskId=u2af201eb-6aff-4d2b-b879-7da51e58236&width=214.49147033691406)
![](https://cdn.nlark.com/yuque/0/2021/png/12518217/1626009436408-b09dbf88-0f90-4a99-866f-55150ce8a096.png#clientId=ud7a02ddf-68cd-4&from=paste&height=237&id=ue7547be6&margin=%5Bobject%20Object%5D&name=image.png&originHeight=505&originWidth=548&originalType=binary&ratio=1&size=326806&status=done&style=none&taskId=u9f6b0011-40fa-4db6-b27b-53f07f83b56&width=256.991455078125)
¶总结
- 不良的拓扑结构,可能给动画绑定UV带来问题
本博客所有文章除特别声明外,均采用 CC BY-NC-SA 4.0 许可协议。转载请注明来自 幻世·游戏人间·N次元!
评论
TwikooGitalk