1
我想在OpenGL中实现骨架动画。在这个阶段,我试图让我的骨骼系统变形成网状。我相信问题在于如何创建矩阵Bone::getMatrix()
。骨骼顶点蒙皮转换
背景:
每个骨骼已经偏移到它的父,如果骨头没有父偏移反而是整个骨架的世界上的地位。骨骼的集合包括骨架。目前,为了测试目的,我在骨骼中有3块骨骼,使变形的网格变形。
此外,问题是,当变形网格时,视觉效果不会产生所需的效果。
代码:
glm::mat4 Bone::getMatrix(){
Bone* parent = getParent();
glm::mat4 rot = glm::mat4(1.0f);
glm::mat4 trans= glm::mat4(1.0f);
glm::vec3 orient = getOrientation();
//Create Rotation Matrix;
rot *= glm::rotate(orient.x,1.0f,0.0f,0.0f);
rot *= glm::rotate(orient.y,0.0f,1.0f,0.0f);
rot *= glm::rotate(orient.z,0.0f,0.0f,1.0f);
//Create Translation Matrix
if(parent != nullptr){
glm::vec3 OFF = offset;
trans = glm::translate(OFF.x,OFF.y,OFF.z);
}else{
glm::vec3 pos = getPosition();
//trans = glm::translate(pos.x,pos.y,pos.z);
}
glm::mat4 PM = glm::mat4(1.0f);
if(parent != nullptr){
PM *= glm::inverse(parent->getMatrix());
}else{
}
return PM * trans * rot ;
}
形变网格:
void Armature::draw(const float& dt){
if(mesh == nullptr){
postMsg("reference copy to mesh is nullptr","draw",34);
return;
}
ArrayVertex3* mesh_Vertex = mesh->getVertex3();
ArrayVertex3 render_vertex;
if(mesh_Vertex == nullptr){
postMsg("mesh vertex structure is null during draw","draw",30);
}else{
render_vertex.reserve(mesh_Vertex->size());
}
int i=0,j=0,k=0;
glPushMatrix();
glTranslatef(10,0,0);
glBegin(GL_POINTS);
for(i =0; i<this->getBoneCount(); i++){
glVertex3fv(glm::value_ptr( glm::vec3( glm::vec4() * getBone(i)->getMatrix() ) ));
}
glEnd();
glBegin(GL_LINES);
for(i =1; i<this->getBoneCount(); i++){
// glVertex3fv(glm::value_ptr(getBone(i)->getTranslationMatrix() * glm::mat3(getBone(i)->getRotationMatrix())));
// glVertex3fv(glm::value_ptr(getBone(i-1)->getTranslationMatrix() * glm::mat3(getBone(i-1)->getRotationMatrix())));
}
glEnd();
glPopMatrix();
//Loop all vertices
for(i = 0 ; i < int(mesh->getNumberVertexes()); i ++){
render_vertex[i].vtx = glm::vec3(0.0f, 0.0f, 0.0f);
int inf_count = (*mesh_Vertex)[i].numInfluences;
//Loop all this vertices influences
for(j=0; j < inf_count; j ++){
Bone *bone = getBone( (*mesh_Vertex)[i].boneIDs[j] );
float weight = (*mesh_Vertex)[i].boneWeights[j];
glm::vec4 original_vert = glm::vec4((*mesh_Vertex)[i].vtx,1.0f);
glm::vec4 original_norm = glm::vec4((*mesh_Vertex)[i].norm,0.0f);
glm::vec3 T = bone->getTranslationMatrix();
render_vertex[i].vtx += glm::vec3( bone->getMatrix() * original_vert) * (weight) ;
//Transform normal
render_vertex[i].norm = glm::vec3( bone->getRotationMatrix() * original_norm) ;
}
(*mesh_Vertex)[i].vtx = render_vertex[i].vtx;
(*mesh_Vertex)[i].norm = glm::normalize(render_vertex[i].norm);
}
}
结果
的旋转不根据其关节位置完成
怎么样逆矩阵结合的工作? – ukaku
什么是反向绑定矩阵?多一点解释? –
我认为问题出在glm :: inverse(parent-> getMatrix())上。如果getMatrix()提供的矩阵用于直接操作顶点,则矩阵需要是全局矩阵。我认为你不需要对父矩阵进行求逆,只需将父矩阵的局部矩阵乘以多个矩阵即可。或者,如果您想稍后连接局部矩阵(例如在绘图函数中),则使用get矩阵函数来获得局部矩阵。父母的全局矩阵的逆可以将您的顶点转移到本地空间,但这会与您的getMatrix()函数冲突,该函数为您提供了一个局部矩阵。 –