I am trying to create a surface model with a bitmap overlaid on it. Using a 600 x 600 pixel bitmap file, I have done the following based on an example found in the mailing list archive: survey Surface -title "Test Surface Image" surface bitmap bitmap.jpg [0 0 45000 32000 600 600 46000 33000] grid-units meter grid 45000 32000 100 100 10 10 grid-flip none #(none)/vertical/horizontal 730 730 725 700 715 710 715 700 660 640 740 740 710 710 760 760 720 675 660 630 760 750 720 720 765 700 685 670 695 670 740 750 730 750 735 700 690 695 730 720 735 750 755 780 775 720 740 730 760 740 760 760 760 760 740 735 765 760 750 710 780 775 770 755 740 730 780 775 755 745 800 790 770 785 775 755 755 780 775 765 800 795 785 825 800 760 755 780 800 780 815 805 800 840 805 775 765 780 810 800 endsurface endsurvey Surface I get a surface model, but in the Loch viewer I only see a grey surface. If I comment out the bitmap line then I get the same model, but the file size of the lox file is much smaller. So my bitmap must be being included, but it is not visible. What am I missing? Footleg