Polygon (TexPoly)

A TexPolyThe TexPoly is a closed textured shape with up to 4 points. The texture can be accurately applied to its surface, thus giving you full control of texturing. Use TexPolys for parking lots, photo realistic tiles, dirt effects on top of normal polygons, spotlight effects at night or for any other type of surface where you need rotated or scaled texturing.

Here is how it works: you assign a texture coordinate to every shape point. This is done visually by dragging the shape's points on top of a texture. Look at the polygon above to see how this works. It is a rectangle, rotated by 45°. A parking lot texture has been applied to it. On the texture, the cars are lined up horizontally. If you drew that shape using the POLY tool, cars wouldn't be lined up with the edges and they probably would be way too small (remember, pixel size depends on polygon scale with POLYs). Look at the MAPPING settings screenshot below. The shape's outline has been rotated and scaled on top of the parking lot texture. In other words, only a portion of the texture is visible.

Seasonal and night effects can be enabled. Use night effects for light effects  at parking lot or to add smooth light effects on the ground.

 

Notes on drawing polygons

Polygons can be convex or concave. Do not draw polygons with intersecting edges. Such polygons will likely not be rendered at all. A polygon should not have its diameter exceeding 1000 meters (about 3000'). Larger polygons lead to an irregularly hazed surface in FS. Note that TexPolys can only have up to 4 points!

 

Setting polygon properties

In order to access the settings dialog, make sure only one polygon is selected. Double-click anywhere on the map to open the dialog. You can also access the settings through the SELECTION\ PROPERTIES... menu item or by left-clicking the polygon handle.

 

General settings

Enter a comment in the COMMENT box. Comments are only there to help you identifying shapes. They appear in the SCASM source file. This is useful in case some hand coding is needed.

 

Texture settings

To select a texture, click on any of the listed files. A preview will be visible on the left. The textures listed are those found in the folder you can set in the FILE\ PREFERENCES... menu item (Click the DIRECTORIES tab). The default TEXTURE folder is in GroundMaker's directory. These textures are also used for OpenGL rendering (when enabled).

Check the CONSTANTLY BRIGHTNESS... options if you want the selected texture to shine at dusk, dawn and night. This options should only be used for light spot effects on the ground. Make sure to disable the NIGHT TEXTURE option. GroundMaker will use the ShadedTexPoly() technique to light the surface. This option should not be confused with the option on the left, which requires an additional texture at night.

If you want seasonal and night light effects to be applied to your shape, check any of the options on the left. FS will then load another texture depending on the chosen season or time of day. The texture you select in the list is the summer and day texture by default.

You will find more info on textures by reading the TEXTURE topic.

 

Mapping settings

MAPPING lets you apply the texture to the shape. The shape's outline is visible on top of the selected texture. Drag the corners where you want them on the texture. Note that this will not distort the shape but 'move' the texture inside the shape. On the left, there is a small version of the shape as it actually is. Use it as a reference when dragging the corners. It is recommended to maintain proportions between the real shape and the outline you drag here in order to avoid a badly distorted texture.

There are preset mappings available (APPLY drop-down box). <NONE> will not make any changes, DEFAULT MAPPING will give you a distortion-free mapping, PHOTO TILE (FULL SIZE) enclose all pixels, PHOTO TILE (1 PXL BORDER) will leave a 1 pixel border around the texture.

 

Visibility settings

The VISIBILITY settings influence the shape's appearance. The most important option is the visual RANGE. Is the viewer's distance to the shape's center greater than the value set here, the shape will be not drawn. You should pay great attention to those values, since setting too large ranges for all shapes will lead to a bad performance of FS. The bottom line is: the less FS has to draw, the higher frame-rates. Small details cannot be seen from far away anyway, so use short ranges for such. To give you an idea what reasonable values are, check out the list below:

Type of surface Visual range (meters)
Airport grass polygon 15,000 - 20,000
Tarmac polygon (e.g. large surface at terminals) 10,000 - 15,000
Long taxiway 6,000 - 12,000
Short taxiway 4,000 - 6,000
Very short taxiway 3,000 - 5,000
Taxiway safety area 2,000 - 3,000

If you are not confident with the metric system, simply use the CONVERTER to convert miles, feet, ... to meters.

Sometimes it is necessary to hide a shape at certain times of day. Push any of the the three buttons (DAY, NIGHT, DUSK/DAWN) to make the shape visible at the chosen time of day. For example, releasing the DAY button will make the shape invisible at daytime.

GroundMaker has a layer option for polygons, it is not recommended to use it though. To change the order of appearance of polygons, go into ARRANGE MODE instead (press last button on the toolbar) and move polygons backwards or forwards. Only unlayered polygons (set layer to NONE, default) can be arranged. Shapes are drawn in the following order by default: polygons, lines, dotted lines and FS runways. Only set a layer if you want to force a shape type above another (polygon above a runway, for example). If you want a polygon to be drawn above a line for example, set its layer to 20.

It is possible to override the general polygon scale setting (FILE\ PROJECT SETTINGS...\ SCALES tab) by enabling the USES OWN SCALE option. This will force GroundMaker into using the scale entered in the input box for that polygon only. The scale has an influence on the texture pixel size and the accuracy of its outline. This feature is for the advanced user only.

 

Merge RefPoint() layer (advanced)

It is now possible to force GroundMaker into combining TexPoly()s of your choice into one RefPoint() command (one coordinate system). This ensures a 100% positioning accuracy and completely removes gaps that would normally occur between adjacent TexPoly()s. Use this feature for photo realistic texture tiles. Enable the feature by setting the REFPOINT() MERGE layer in the TexPoly()'s settings dialog (LAYER drop-down box in VISIBILITY tab). All TexPoly()s with that layer set will be merged into one RefPoint(), its center being the center of the map.

Before compiling to BGL format, you must set the scale and layer to be used for that RefPoint(). Click the FILE\ PROJECT SETTINGS... menu item and select the ADVANCED tab... It is recommended to set no layer (NONE). Merged TexPolys are drawn before any other scenery items by default; this makes sure that all other shapes lie on top of the merged TexPoly()s. You should enter a realistic value for the scale: 0.5 - 2. Since GroundMaker 'internally' works with a scale of 0.5, it is strongly recommended to set the scale to 0.5.

Note that FS only allows coordinate values (integer) ranging from -32,766 to 32,765, 1 being the size of a scale unit. At a scale of 0.5, the merged TexPoly()s can cover an area of about 32 x 32 km, at a scale of 1 an area of approx. 65 x 65 km (the grid in the drawing area covers an area of 10 x 10 km). In other words, the smaller the scale, the smaller the area the merged TexPoly()s can cover. Merged TexPoly()s which lie outside that area will generate an error when compiling to BGL format.

This feature has not been fully tested and is there for experimental purposes only. Note that it may be removed if proven unnecessary or being too complicated!