Hi,
I played around a bit with Sydney and using ADE came up with this:
This is essentially identical to the FS2004 version.
Here is how I used ADE - these instructions look complicated, but only took a few minutes. In summary I:
1. Loaded the FS2004 airport as is into FSX.
2. Went to top down view, slew mode (Y key), and went to true north (Ctrl-Spacebar)
3. Zoomed in/out until the entire airport (including the bay) was visible.
4. Took a screen shot (Prnt Scrn)
5. Loaded it into my paint program (PSP), cropped it so only the airport and bay was included, and placed the saved JPG image into the ADE/FSX/Images folder.
Note that in the default FSX there are extensions into the bay. While the ground itself has been excluded by the existing FS2004 files, the shorelines are still there and the water is raised up to the airport level in those areas.
6. Started ADE and used File/Open Airport from BGL to open the AFCAD file for the airport(AF2_YSSY61.BGL in this case).
7. Used Add.../Image to add my top down image, and clicked OK.
8. Clicked on the {small) image, right clicked and chose Edit Object.
9. Clicked the Preserve Aspect Ratio box to check it.
10. Increased the Width to about 19000 ft, the estimated width of my image (based on the runway's length).
11. Clicked OK and dragged the image around until it matched up with the runways and taxiways (approximately).
12. Went back to Edit Object and changed the Width to get it closer, then step 11. Then repeated this and step 11 until it matched perfectly.
13. Right clicked the image and chose Lock Object.
14. Chose the Add Polygon button (green shape) and drew a small triangle anywhere on the green airport polygon (away from anything else). Double click the last vertex and the triangle will turn gray.
15. In the box that appeared, I chose Exclude General and Airport Backgrounds. This removes the entire FSX airport polygon.
16. Chose the Add Polygon button (green shape) and drew a small triangle crossing one of the shorelines out in the bay. Double clicked the last vertex.
17. In the box that appeared, I chose Exclude General and Shorelines. This removes all the shorelines in this area. (If you find other shorelines in other parts of the airport, you can copy and paste this triangle elsewhere.)
18. Chose the Add Polygon button (green shape) and drew a small triangle crossing a white ramp area out by the bay. Double clicked the last vertex.
19. In the box that appeared, I chose Exclude General and Parks (polygons). This removes the white polygon in this area. I did the same thing in other parts of the airport, by selecting the polygon (click it), right clicked and chose Copy Object. Then right clicked next to another white polygon and chose Paste Object. Then I dragged it into position.
20. Chose the Add Polygon button (green shape) and drew a small triangle crossing a road I don't want. Double clicked the last vertex.
21. In the box that appeared, I chose Exclude General and Roads. This removes the terrain road in this area. I did the same thing in other parts of the airport, by selecting the polygon (click it), right clicked and chose Copy Object. Then right clicked next to another road and chose Paste Object. Then I dragged it into position. Here are 4 of these:
BTW, you can hide all these gray Exclusion polygons by going to the View menu and choosing Terrain Exclusions (it's a view toggle).
22. After removing the Airport Background in step 14, the runways no longer display completely. So I created a flatten polygon around the runways. I chose the Add Polygon button (green shape) and clicked, clicked, clicked to form the shape. Double clicked the last vertex and the shape turned yellow. Sometimes you will need to extend this polygon around the complete airport polygon, it depends on the airport.
23. In the box that appears, I chose Airport Background and Flatten. I kept the Altitude set at the airport default (6.4 meters), which ADE should provide as a default value.
If the yellow polygon is covering ADE objects below it (like the runways and taxiways), click the polygon, right click and choose Move to Back. That will move it to the bottom of the stack.
22. The water in the bay that used to be land is raised up to 6.4 meters, instead of 0 m. So I created a flatten polygon around this part of the bay. I chose the Add Polygon button (green shape) and clicked, clicked, clicked to form the shape. Double clicked the last vertex and the shape turned yellow.
23. In the box that appears, I chose Airport Background and Flatten Mask Class Map ExcludeAutoGen. I set the Altitude to 0 m, which is sea level.
23. There is a missing piece of the green airport background along the south side of the airport. To replace it I chose the Add Polygon button (green shape) and clicked, clicked, clicked to form the shape. Double clicked the last vertex and the shape turned yellow.
24. In the box that appears, I chose Airport Background and Mask Class Map ExcludeAutoGen. I kept the Altitude set at the airport default (6.4 meters), which ADE should provide as a default value.
If you don't want to see any of these yellow polygons, use the View menu and choose Airport Backgrounds (it's a view toggle).
25. I moved a road from the fuel tanks at the north side of the airport that was in a lake to run along the east side of the lake shore.
26. I hope you have been saving your airport as you have been editing. File/Save Airport. I saved mine as YSSY_ADEX_CC.AD4 in the ADE/FSX/Projects folder.
27. Now you need to compile it into a BGL file. Use File/Compile Airport. In the box that appears, give your new BGL file a name in the middle box - I left mine the default YSSY_ADEX_CC. Click the Open Folder button. Browse to your FSX/Addon Scenery/YSSY 1961 Sydney Kingsford Smith Intl/scenery folder, and click the Save button. You will need to have FSX not running when you do this, and if you have compiled this before you should overwrite the old one.
28. Finally move the AF2_YSSY61.BGL file from the FSX/Addon Scenery/YSSY 1961 Sydney Kingsford Smith Intl/scenery folder into the FSX/Addon Scenery/YSSY 1961 Sydney Kingsford Smith Intl folder to inactivate it and save it as a backup.
That should do it.
I thought you might also want to see a few images about the ModelConverterX conversion.
The signs start out by looking like this in FSX:
When opened in MCX, I press the Material Editor button, click on the YSSY_Signs material (at the left), choose Set Default Transparent from the drop down box at the top, set the Alpha Test Level at 128 or so (in this case - this varies from 15 to 200), and press the Apply button:
Close the Material Editor with the red X in the upper right corner.
Use the green arrows to move between objects in a file. When you have edited all transparent objects, choose Export Scenery, as an FSX BGL file (drop down box). Overwrite the original, but back up the entire folder first.
Take a look in FSX and if they still have transparent areas, increase the Alpha Test Level number. If the entire sign has disappeared, lower the number. You want the number as low as possible, but the entire lettering still visible and no transparent areas.
They end up looking like this:
Hope this helps,