Help me plz. I don''t know how resolve this problem: i have to drag and drop a cube. Now i can pick it up and if i hold the left button on i can change it position, but the scene doesn''t update and i don''t see my cube moving. If i reshape the screen the cube appear in the new and correct position. Down here i post my code, with the hope someone can help me (plz do not tell me dude or lamer or something similar,..... i just know it by myself). //Convert screen coordinates to OpenGL coordinates. GLdouble *GetOGLPos(int x, int y) { GLint viewport[4]; GLdouble modelview[16]; GLdouble projection[16]; GLfloat winX, winY, winZ; GLdouble pos[3]; glGetDoublev( GL_MODELVIEW_MATRIX, modelview ); glGetDoublev( GL_PROJECTION_MATRIX, projection ); glGetIntegerv( GL_VIEWPORT, viewport ); winX = (float)x; winY = (float)viewport[3] - (float)y; glReadPixels( x, int(winY), 1, 1, GL_DEPTH_COMPONENT, GL_FLOAT, &winZ ); gluUnProject(winX, winY, winZ, modelview, projection, viewport, &pos[0],&pos[1], &pos[2]); return pos; } #define BUFSIZE 512 void pickPacket(int button, int state, int x, int y) { GLuint selectBuf[BUFSIZE]; GLint hits; GLint viewport[4]; if (button == GLUT_LEFT_BUTTON && state == GLUT_DOWN) { glGetIntegerv(GL_VIEWPORT, viewport); glSelectBuffer(BUFSIZE, selectBuf); (void) glRenderMode(GL_SELECT); glInitNames(); glPushName(0); glMatrixMode(GL_PROJECTION); glPushMatrix(); glLoadIdentity(); /* create 1x1 pixel picking region near cursor location */ gluPickMatrix((GLdouble) x, (GLdouble) (viewport[3] - y), 0.01, 0.01, viewport); //glOrtho(-8, 8, -6, 6, -100, 100); glOrtho(-8*zoomfactor-translatefactor,8*zoomfactor-translatefactor, -6*zoomfactor, 6*zoomfactor, -100, 100); drawScene(GL_SELECT); glPopMatrix(); glutSwapBuffers(); reshape(Width, Height); hits = glRenderMode(GL_RENDER); if(hits>1) { Hitten=selectBuf[7]; } processHits(hits, selectBuf); } if (button == GLUT_LEFT_BUTTON && state == GLUT_UP) Hitten=0; } void myMovedMouse(int x, int y) { if(Hitten!=0) { Container *tmp; Packet *tmp_pkt; tmp=Cont; while(tmp->Obj->name!=Hitten) tmp=tmp->next; GLfloat X,Y,Z; X=GetOGLPos(x,y)[0]; Y=GetOGLPos(x,y)[1]; Z=GetOGLPos(x,y)[2]; Modifica_Origine(X, Y, Z, tmp->Obj); //glutPostRedisplay(); } }