animation - Bone Vertex Skinning transformation -

i trying implement skeletal animation in opengl. @ stage, trying have bone system deform mesh. believe problem how create matrix bone::getmatrix().

background:

each bone has offset it's parent, , if bone not have parent offset instead world position of entire skeleton. collection of bones comprise skeleton. currently, testing purposes, have 3 bones in skeleton deforming skinned mesh.

again, issue when deforming mesh, visual result not produce desired effect.

code:

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 ; } 

deforming mesh:

void armature::draw(const float& dt){     if(mesh == nullptr){         postmsg("reference copy mesh nullptr","draw",34);         return;     }      arrayvertex3* mesh_vertex = mesh->getvertex3();     arrayvertex3 render_vertex;      if(mesh_vertex == nullptr){         postmsg("mesh vertex structure 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( =0; i<this->getbonecount(); i++){             glvertex3fv( glm::value_ptr(    glm::vec3(  glm::vec4() * getbone(i)->getmatrix()  )   ));         }         glend();          glbegin(gl_lines);          for( =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 vertices     for( = 0 ; <  int(mesh->getnumbervertexes()); ++){         render_vertex[i].vtx = glm::vec3(0.0f,  0.0f,  0.0f);           int inf_count = (*mesh_vertex)[i].numinfluences;          //loop 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);      } } 

result

the rotation not done according joint location

i fount bone matrix function bit chaotic. understanding, vertexes need transformed global transformation matrix. global transformation matrix concatenation of local transformation matrix. following code used calculate global transformation. article useful. http://graphics.ucsd.edu/courses/cse169_w05/2-skeleton.htm

some of previous work using glsl + assimp + glm http://www.youtube.com/watch?v=bxbfvl-msyw&list=hl1385555185&feature=mh_lolz

glm::mat4 t = glm::translate(bone->offset); glm::mat4 r = glm::tomat4(bone->rotate);  glm::mat4 s = glm::scale(bone->scale); glm::mat4 localtransform = t * r * s;   if(bone->getid()!=0) {     bone->globaltransform = bone->getparent()->globaltransform * localtransform; } else {     bone->globaltransform = localtransform; }  (uint = 0 ; < bone->getchildren().size() ; i++) {     updatetransform(bone->getchildren()[i]); }