gpu蒙皮的矩阵计算

Let's take for instance this code, which I used to animate characters in a game I worked. I used Assimp too, to load bone information and I read myself the OGL tutorial already pointed out by Nico.

glm::mat4 getParentTransform()
{
    if (this->parent)
        return parent->nodeTransform;
    else 
        return glm::mat4(1.0f);
}

void updateSkeleton(Bone* bone = NULL)
{ 
    bone->nodeTransform =  bone->getParentTransform() // This retrieve the transformation one level above in the tree
    * bone->transform //bone->transform is the assimp matrix assimp_node->mTransformation
    * bone->localTransform;  //this is your T * R matrix

    bone->finalTransform = inverseGlobal // which is scene->mRootNode->mTransformation from assimp
        * bone->nodeTransform  //defined above
        * bone->boneOffset;  //which is ai_mesh->mBones[i]->mOffsetMatrix


    for (int i = 0; i < bone->children.size(); i++) {
        updateSkeleton (&bone->children[i]);
    }
}

本质上是教程 GlobalTransform>带有Assimp的骨骼动画或正确的根节点变换scene->mRootNode->mTransformation是从局部空间到全局空间的变换.举个例子，当在 3D 建模器中(例如让我们选择 Blender)创建网格或加载角色时，它通常(默认情况下)位于笛卡尔平面的原点，其旋转设置为身份四元数.