Hello, I notice a strange thing in Thérion (5.2) When you put a window in a wall (wiki chapt 3.4.6 Window in the wall http://therion.speleo.sk/wiki/doku.php?id=tbe:wiki3) if the survey of the galery arriving in the window (survey points 2, 10 and 11 in the exemple of the wiki), is drawn in the scrap in the reverse side ( -flip horizontal for the scrap). the lines (wall lines) must be reversed in the join command. In my drawing, the line up ends on the windows, and the line down began in the window. The join command should be join up@MeandreEst:end <mailto:up@MeandreEst:end> window@GrandBlack:end join down@MeandreEst:0 window@GrandBlack:0 but this join command corrupt the drawing (I don't know how to say it in english : I have gallery compression) If I change the join like that : join up@MeandreEst:0 window@GrandBlack:end join down@MeandreEst:end window@GrandBlack:0 The drawing is perfect (I am in an extended survey). An other tip : the survey of my branch(MeandreEst) was done from the end to the entrence (the window). I had no problem with an other branch witch was surveyed from the entrance (the window) to the end, and the scrap drawn in the same direction of the final survey (no -flip horizontal). If you can have a look. I have already solved my problem (reversing the end and 0 parameter for the lines) but it seems a bit strange. Thanks a lot for your work. Gilbert