Hi,I'm trying to build an airport in Gmax with a highway underneath a taxiway bridge. The taxiway is on the ground level. I used bitmaps applied to polygons in Gmax. Under the taxiway there is an invisible runway to get a smooth area. Then there is another ground layer I made in Gmax which goes below ground level where there is supposed to be a highway later on. To make the area below zero visible I added a flatten area to give room below the invisible runway. My problem: everything below ground level doesn't seem stable. I get all kinds of bleed through effects. When I move the aircraft the lower ground level doesn't move in the right perspective, if that makes any sense. I hope you get the idea from the images I uploaded. If you use the taxiway as a reference point you can see that the edge of the area going below taxiway level doesn't stay in place when I move the aircraft.Thanks for any help I can get,Matthiashttp://forums.avsim.com/user_files/24378.txthttp://forums.avsim.com/user_files/24379.jpghttp://forums.avsim.com/user_files/24380.jpg

Hi Matthias,This is an interesting problem :).What you see is the same thing you see when you have set the altitude of the runway or a flatten wrong in normal scenery. But in your case that altitude offset is wanted of course.When you look in spot view, does the aircraft then drive on the taxiway or does it drop onto the lower highway?

Hi Arno,thanks for dealing with this so quickly.The aircraft reamains on the taxiway level all the time because of the invisible runway that I added. It also covers the "ditch" area. I'll check what happens when I take the invisible runway out.Matthias

Hi Matthias,I just did some more thinking. Can it be that some of the polygons of your taxiway are drawn at the altitude of the flatten? If they have a RefPoint type 7 they will always be drawn at the altitude of the flatten. This can give a strange effect if you drive on the higher (invisible) runway. Maybe you can try RefPoint type 2 (there you can specify the exact altitude of the RefPoint).

Hi Arno,can you please tell me where I find a RefPoint and how I change the altitude. Is this part of a sca file? I have so far only edited asm files.BTW: Is there a tutorial somewhere that tells you how to edit asm files? I'm always amazed that cracks like you know what to change. You didn't find that out by trial and error. did you?Thanks for your help,Matthias

Hi Matthias,Did I read it correct that you made the polygons with GMax? Then you would need to change the RefPoint in the ASM source. I think by default GMax indeed uses type 7.Here is a link to a tutorial about tweaking GMax files I am working on. It is a collection of the tips on my website, plus some new material, but it is not finished yet :). Maybe you can still find some things there you want to know.http://home.wanadoo.nl/arno.gerretsen/down...ng_for_gmax.pdf