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rhumbaflappy

Ground2k Land on the right? Help!

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Guest ScottR

I am trying to use Ground2K to alter the coastline by placing a new shore line that cuts across a default bay and fills in the water with land between the new shore and the original coastline.I excluded the default coastline, then on the Polygons/Lines menu select "Poly with shore", under LWM/Poly select "Land", under Line/Shore select "Land on right", and change layer to "9".I start the new shoreline at the top and work down the image so the land should be on the right? Three bgl's are produced, an exclude.bgl, a _3.bgl and a _9.bgl. I place these in a scenery folder and activate in FS2002.However, the new shore line shows up Ok but the land is on the "left" (when looking down the page from the top) and there is water between the default land and the new shore.I have tried every combination of starting the line from top or bottom, and ticking or unticking "Land on the right", but the land always shows up on the wrong side of the shore.I must be missing something simple here!!! Can anyone help?

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Hello ScottR,looking at your second picture, it seem to me, that you created a concave (sp?) polygon, where start and endpoint of your coastline connect over the open sea.You might correct this by creating a polygon which explicitly closes over the land. Maybe its better to do it in two steps:a) create a land polygon to correct the coastline:( draw the the shoreline to get waves.Hope it helps,Edgar

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Hello Scott,Edgar, as always, is right and his solution will solve your problem.Just a clarification for anyone else:Land (or Water) is a polygon that masks that property and represents the underlying land class value (or water class value.)A polygon is a CLOSED many-sided figure. Keep that in mind.When you draw a coast, you usually only draw the part that fronts the water, not the entire closed polygon. Ground2K automatically closes the polygon by drawing a straight segment from one end of your curve to the other.If you selected Land in the LWM/Poly section, the interior of your polygon is masked as land. See your coast:http://forums.avsim.com/user_files/17231.jpgYou can see that a straight segment closing this curve would create a polygon that is the contrary of what you want.Just extend the ends of your polygon in such a way that when it is closed, you will get the land mask as you desire:http://forums.avsim.com/user_files/17232.jpgOr you could even close the polygon yourself in order to ensure this. Please note that you cannot use the "Poly with shore" option for this because then you would get a beach all along the curve that you have drawn, even including going through land. So, you must draw a "Poly without shore" and select Land in the LWM/Poly section, draw your coast polygon, then draw a new "Line/LakeShore" of a beach along the parts of the curve that face the water.It often happens that someone draws a coast and then gets the dreaded "lake/curve : a curve crosses itself" error. It is quite probable that the curve does NOT cross itself as they have drawn it. But, a polygon is a closed figure and Ground2K closes the curve, often forcing an error. See the following example:http://forums.avsim.com/user_files/17233.jpgObviously, the straight segment from one end to the other will now cross over the polygon and therefore the error. The solution here as well is to follow Edgar's advice and extend the curve in such a way that the closing segment does not cross over it.(Boy, I feel like Dick Ludowise with all these long explanations!)Best regards.Luis

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Guest ScottR

Edgar, LuisOf course!! Now I understand the concept of the closed polygon.Thank you for your help.Regards

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