hi, i am trying to convert two points that are used to render a line from space to screen points like this:

  Label.pStartScreen=cam.WorldToScreenPoint(Label.startPoint);
  Label.pEndScreen=cam.WorldToScreenPoint(Label.endPoint);

then i tried to render them like this:

  line.SetPosition(0,Label.pStartScreen); 
  line.SetPosition(1, Label.pEndScreen); 

but nothing happens

if i do this

  line.SetPosition(0,Label.startPoint); 
  line.SetPosition(1, Label.endPoint); 

the line renders correctly but these are initial 3d points, so the line is rendered in world space...

i am using this to render the line and rectangle that will hold the information about object line points to, so rectangle obviously needs screen space coords, these are converted the same way as above and the Rect appears where it should...so i dont know what is going on here? any ideas?

EDIT:

also i tried this:

GL.Begin(GL.LINES); 
  GL.Color(Color(1,1,1,1)); 
  GL.Vertex3(Label.pStartScreen.x,Label.pStartScreen.y,Label.pStartScreen.z);
  GL.Vertex3(Label.pEndScreen.x,Label.pEndScreen.y,Label.pEndScreen.z); 
 GL.End(); 

and it doesnt render anything when i use startPoint and endPoint, which are in world space, then it renders nice 3D line... i dont know what is happening, this should render in the screen space...