记录一下最近学到的corrective blendshape知识.

问题描述

First, a basic scene is built, pCylinder1 is rigged and skinned,

Now, suppose we are not satisfied with the elbow shape, want it change it a little bit. 例如一个手臂的骨骼动画已经搞好了, 后面发现在形状上还想改进一下, 那怎么办呢?

If we select vertices and move them (adding vector delta to these vertics) on the skinned ...

做demo都只是对mesh做一次修改, 但是好像在一个成熟的程序里面往往是很多次修改的叠加.

引言

以前对mesh的修改都是例如 mesh.setVertexPosition( vertexID, newPos ); mesh.setVertexTC( tcID, newTC ); 这样直接改[1], 从读书时候到现在都是这么simple and naive:-) 而对于maya的case就没有这样简单了，例如去看maya>devkit>splitUV example [2], 套用上面直接修改的方法, 要split一个uv的话，那直接用MFnMesh加几个新uv, MFnMesh::setUV(new uv id, uv value) 就ok了, 可是故事没有这么简单....

Construction History and Tweak

直接摘抄两段来看看:

All the operations that can be performed on a polygonal ...

学maya时候有些新概念要记录一下，否则忘得快.

先在一个新场景里面拖一个多边形球polygon sphere出来,
打开Outline窗口, 看到一个pShere1, 选择Display/Shapes, 又看到pShere1下面还有一个pSphereShape1. 而在hypergraph: connection 窗口看到一共四个东西, 其中两个就是上面的pSphere1 and pSphereShape1, 而且其中三个是有连接关系的。从左到右它们分别是:
+ polySphere1: 控制参数, 例如半径radius, axis/height上的布线密度等;
+ pSphereShape1: 这个就是实际的shape node, 形状.
+ initialShadingGroup: 用于画这个球的.
+ pSphere1: transform node, 决定了球在空间位置.

import maya.cmds; 

maya.cmds.polySphere()                  # 用script建一个球 
# Result: [u'pSphere2', u'polySphere2'] # 返回就是transform node, shape node. interesting part ...

涉及maya plugin开发的时候，怎么debug呢?

Attach to maya process ... 寄生

step 1. maya plugin manager (Window -> Settings/Preferences -> Plug-in Manager)中load your custom plugin. This plugin need to be built by the same compiler version of maya, 也许不需要. step 2. at your visual studio project of that custom plugin, Tools -> Attach to ...

最近接触了一点maya blendshape programming, 稍微记录一下。

BlendShape deformer basis (基础)

先说明一个特点，当drag一个cube or sphere物体的时候，会生成两个nodes, 具体的细节请看maya scene graph，DAG。

To create a simple blendshape example,
Polygon mode, create a cube, we have ;
Select cube1, Shift+D, we have , move cube2 a little bit away from cube1.
Select cube1, Shift+D, we ...