# Big Gat (hole) in the ground when creating water polygons ...

been trying to create some water polygons yet for some reason i end up with a massive hole which isn't to my liking... however seems useful if i had to model the great hole of kimberly... haha

anyway what must one do to prevent the water polygons being at the bottom of the hole instead on the surface where intended?

A. could it be the amount of points used?

as a strange thing ive noticed is that roads or other poly's do not do this...

Regards
Gareth
Virtual Aerospace Design South Africa

Last edited:

#### mikrco

Resource contributor
Although I don't use FSX KML, I would assume you need to set an elevation for your polygon points.

#### Mace

been trying to create some water polygons yet for some reason i end up with a massive hole which isn't to my liking... however seems useful if i had to model the great hole of kimberly... haha

anyway what must one do to prevent the water polygons being at the bottom of the hole instead on the surface where intended?

Iron Mike is right, and he doesn't even use FSX_KML.

Do you mean as in making a lake?

You need to figure out what the elevation of your lake is, in meters.
Then use that elevation for all of your points.

#### MatthewS

Resource contributor
You need to figure out what the elevation of your lake is, in meters.
Then use that elevation for all of your points.

Like Mace said, and when you know the elevation, use the Vertice Editor in FSX KML and click on the "Set Elevation" button to set the elevation for all vertices.

Resource contributor
I have the same problem. Tried to set elevation in google earth, used options "clamped to ground" and "relative to ground" with value 0 and always ended up with a "canyon", elevation of water poly being zero - meters or feet.

So, if I got it right the only solution is to set altitude to ABSOLUTE value that is close to surrounding terrain and get a water poly with all points at the same altitude which is O.K. for lakes, but what about rivers, their surface is sloping, and if we can not use function clamp to ground, how can one produce a decentlly looking river that follows the terrain slope?

#### rhumbaflappy

Staff member
Resource contributor
Hi all.

I don't know how this is implemented in this program, but the terrain.cfg has this:

Code:
``````// Legacy_LandWaterMask_Water_NoFlatten
[Texture.381]
Color=FF638AC2
Textures=OCEAN_SEA_LARGE_LAKE_0
FlattenMode=none
LandClassRemapType=none
ExcludeAutogen=Yes
RenderToTexture=Yes
RenderPriority=80000
Water=Yes``````

And that GUID should have mesh-clinging water, with no elevation needed.

Dick

#### MatthewS

Resource contributor
Yes... in FSX KML there is a tag called

which will make your water poly cling to the underlying terrain, like Dick said.

Resource contributor
All I can say is a BIG THANKS!

Resource contributor
Regarding the water polys - I tried somewhat different approach that also works perfectlly:

Since I work on a river that is reasonably wide and flows over terrain that has a very gentle slope, some 44 meters in 25 km, I tagged the water poly Hydro_Polygons_Generic_River_Perennial, opened vertices and edited their altitude manually (river flows NW to SE) in a way that most NW points (top and bottom of the table of vertices) have higher values than center or SE end of the river. I worked in pairs of vertices, reducing altitude in steps of 1 meter. Actually I measured the altitude I needed at 3 points only (top,middle, bottom), since I was considering this work kind of a test, and simply interpolated the other values, but the result was so surprisingly nice looking, I don't even need to touch anything anymore, just continuing in the SE direction

#### Mace

Since I work on a river that is reasonably wide and flows over terrain that has a very gentle slope, some 44 meters in 25 km, I tagged the water poly Hydro_Polygons_Generic_River_Perennial, opened vertices and edited their altitude manually (river flows NW to SE) in a way that most NW points (top and bottom of the table of vertices) have higher values than center or SE end of the river. I worked in pairs of vertices, reducing altitude in steps of 1 meter. Actually I measured the altitude I needed at 3 points only (top,middle, bottom), since I was considering this work kind of a test, and simply interpolated the other values, but the result was so surprisingly nice looking, I don't even need to touch anything anymore, just continuing in the SE direction

(Question directed at everyone )

Does this mean that when you do the above, and you load your scenery in TMFViewer, it shows a "Slope" property for your water polys?