Problem with DEM coordinates

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Problem with DEM coordinates

Postby koiravahti » Fri 28 Jan 2005 - 00:01

There's a bug or some problem with DEM center coordinates and scenery editor. Here's my observations:

I made a bmp dem model out of a local chart. I opened it with DEM Builder 1.2 and entered correct center latitude and longtitude and other information. I tested this scene projection dem by converting it to new dem with geographic projection. Coordinates were shown correctly in this dem. Then I converted this dem back to scene dem and opened it in Scenery Builder. I defined DEM patchgrid so that center of grids wasn't in the center of dem map. Result was that coordinates were displayed incorrectly in scenery. I did some testing with different patch sizes and offsets and noticed that scenery builder uses dem's center coordinates as patch grid's center coordinates. So coordinates goes wrong if patch grid isn't aligned in the center of the dem.

Is there some workaround for this? I'm trying to make a scenario for navigational exercises so coordinate precision would be a nice thing :)
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Joined: Thu 27 Jan 2005 - 23:42

Postby Guest » Sat 29 Jan 2005 - 21:26

It has been a long time since I made a scenery but I saw your mail when I wanted to post a new one.
Anyway did you have a look at: It explains how I did it. I remeber the coordinates being precise since I used it together with oziexplorer mapping/chart software.

Postby koiravahti » Mon 31 Jan 2005 - 17:03

Yes I did. Actually this was the tutorial which inspired me to try making my own scenery :) Thank You for that!

I solved this coordinate problem by making a new DEM bmp-file for smaller chart portion. Then I calculated this new charts center coordinate and pixel resolution. After that I opened it to Scenery editor and used the default patch settings and all wen't ok. Last evening i positioned all buoys and other navigational stuff from electronic chart software with real coordinates and they fell on right places... I was quite impressed :) I only wish there was proper lights and some way to put trees on islands (in Finland we have lots of trees so scenery looks kind of bald without them).
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Joined: Thu 27 Jan 2005 - 23:42

Postby Barry » Wed 02 Feb 2005 - 00:16


I posted in sailsim forum but just noticed your post here.
You can get any item to light up. The part that you want lit you don't join to main model. Again open file with wordpad and change 0 to 1 against the correct line. There is another thread with more details on.
I lit the top of the lighthouse up and made a lighthouse beam from a cone, trouble is it was lit during the day also.

You can now make trees in the latest version of the motorboat sim.
These apparently won't show up in the Object Editor or Scenery Designer when made but will show up as a tree in the simulator. You just put the image of a tree on a flat sheet with a black backround, interlace 2 or several together, set the alpha texture in Blender, and tree shows up OK and have put a few into the motorboat sim trying it out.

However I will wait until the function also works in sailsim 5 as motorboat sim doesn't run too well for me ,and at present all you see in the sailsim is black flat sheets with a picture of a tree on them.
I mentioned in in the last section of the Blender tutorial on my site.

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