//translates the cylinder  by [10, 20, 30]
multmatrix(m = [ [1, 0, 0, 10],
                 [0, 1, 0, 20],
                 [0, 0, 1, 30],
                 [0, 0, 0,  1]
               ]) cylinder();

//rotates by 45 degrees in XY plane and translates by [10,20,30]):
angle=45;
multmatrix(m = [ [cos(angle), -sin(angle), 0, 10],
                [sin(angle), cos(angle), 0, 20],
                [0, 0, 1, 30],
                [0, 0, 0,  1]
              ]) union() {
   cylinder(r=10.0,h=10,center=false);
   cube(size=[10,10,10],center=false);
}

module rotateX(angle){
    multmatrix([[1,0,0],
    [0,cos(angle), -sin(angle)],
    [0,sin(angle), cos(angle)]])
    child(0);
}

module rotateY(angle){
    multmatrix([[cos(angle),0,-sin(angle)],
    [0,1,0],
    [sin(angle),0,cos(angle)]])
    child(0);
}

module rotateZ(angle){
    multmatrix([[cos(angle), -sin(angle),0],
    [sin(angle), cos(angle),0],
    [0,0,1]])
    child(0);
}

module reflectXY(){
    multmatrix([[1,0,0],
    [0, 1,0],
    [0,0,-1]])
    child(0);
}

module reflectXZ(){
    multmatrix([[1,0,0],
    [0, -1,0],
    [0,0,1]])
    child(0);
}

module reflectYZ(){
    multmatrix([[-1,0,0],
    [0, 1,0],
    [0,0,1]])
    child(0);
}

module translatejb(x,y,z){
    multmatrix([[1,0,0,x],
    [0, 1,0,y],
    [0,0,1,z],
    [0,0,0,1]])
    child(0);
}