Creating Photoscenery

[SwissCyul]

Hello once again.

 

I want to create photo scenery for the Montreal Area.

I downloaded the Photo scenery tool, but i don't know how to work it.

Do you have to download photos from google earth?

 

I excuse for stupid questions but i really need some help here.

 

Thanks for your support 

[Orcair]

Whatever you do, do not use google images. They are all copyrighted. However, the USGS has photos available for much of the world which you could use.

[SwissCyul]

Ok thanks i will try that 

[Orcair]

Glad to be of service

[SwissCyul]

[chris k]

Howdy,

I've been asked quite a few times (via PMs) on how to make good quality orthophoto scenery. I thought I'd share this with the rest of the crew here. I'll break it down by section.

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STEP #1 - Find Quality Ortho-Photography

First off, is to source some quality photo imagery. This is probabaly the most difficult step in producing great photo scenery.

Where do you find such files? I will leave this as an exercise to the reader. Some sources/sites such as http://www.koordinates.com/ and http://nearmap.com/ offer quality New Zealand and Australian Imagery respectively - some free, some with a modest price. For other locations, check with the local government websites. I know that a few cities and certain Canadian Provinces offer ortho-rectified imagery for free on their websites. In the USA, check the United States Geological Service (USGS) website or NASA.

If you find a great source of Ortho-Rectified Imagery available to download to the general public, feel free to post it here and share the knowledge. Please don't ask me where one can find scenery for <location X>. Your guess is as good as mine - "Google Search" is your Friend.


Method 1: Using GeoTIFF FIles

Ideally, you want the file format to be in GeoTIFF format. What is special about GeoTIFFs? They encode the actual latitude/longitude of the photo scenery into the file itself. Which means, when you load the image into WED for placement, it automatically 'snaps into place' precisely where it occurs in the real world. GeoTIFFs are a file format... just like PNG or JPEGs.

http://en.wikipedia.org/wiki/GeoTIFF

You will want photography to be at least 1m resolution (1 pixel=1m2); else it just isn't worth it. I highly suggest getting the most detailed imagery possible, as you can always down-sample the imagery later for distribution. I normally work in 10cm to 15cm resolutions, (1 Pixel = 10cm2, or 15cm2).

2. Ensure that your source of photography supports downloading the imagery in GeoTIFF format

....specifically WGS84 lat/long format. If they offer it in another projection format, see if they can convert it to WGS84. Also ensure that the coordinate system is using latitude/longitude, and not some other geodisc format. Sites such as koordinates.com and nearmap.com offer tiles to download in various formats; ensure you use the correct one.

3. Check the licensing from the photo provider

....to ensure you can re-use the work. Some providers do not allow use of the photography in any redistributable work; and hold copyright over the imagery. Others are Free-to-do-as-you-please (i.e. Creative Commons, GPL, BSDLicence, etc.). Ensure that what you're using can indeed be redistributed and you are not going to break copyright.

4. Purchase/Download the GeoTIFF tiles from the photo provider.

This may be anywhere between $free and $1000; depending on the provider, the size of the imagery, the resolution of the Imagery, any DVD burning costs or distribution costs. Much of what I have downloaded is anywhere between 600Mb and 1.5 Gbytes of data. Some providers - the imagery is free, but they charge me to burn and mail me a DVD (usually around $20 or so) if I am requesting 2-3 Gb of data.

Then, Start reading here for some background: http://wiki.x-plane....n_overlay_image

5. Make a Directory in your /Custom Scenery/MyProject to store your downloaded files.

Call the directory "Tiles" or "images" or something like that.

6. Copy your GeoTIFFs into your /Custom Scenery/MyProject/Tiles/ directory

7. Load the GeoTIFFs into WED using the "add image overlay" function.

Make sure you import the files from your /Custom Scenery/MyProject/Tiles directory. WED should immediately 'snap' the imagery into the correct place in the world. If it does not, the image you have is not in WGS84 lat/long format - Go back to step 2 and get the corrected projection/format.

8. In WED, select your Image/Images and select "Create Draped Polygons".

This will now create .POL files (polygon definition files) in the directory that you originally selected the imagery from. This is why it was very important (in Step 7 above) that you loaded in the GeoTIFFs from your /Custom Scenery/MyProject/Tiles/ directory, and not from some other place like "Downloads" or "My Desktop", else X-Plane will have no idea where the files really are.

WED and X-Plane use relative pathing from the root of your 'MyProject" directory.. hence all your photos and .POL files and imagery need to be within your /Custom Scenery/MyProject/ directory structure somewhere; else it will not work when you go to redistribute your scenery to someone else - We don't have access to your desktop =)...

Save your WED project, and quit WED.

9. Convert the GeoTIFF files in your /Custom Scenery/MyProject/tiles/ directory into PNGs using power-of-two dimensions.

Ensure that when you do the conversion, you convert the original GeoTIFF resolution into a 1024x1024 or 2048x2048 PNG files. X-Plane can only deal with "powers of two" per side. For example, if your Original GeoTIFFs were 4800x3600, you should downsample them to 2048x2048. You will lose a bit of detail, but will still look fine. Your image conversion software will probably dither/blend the imagery into a smaller file in an attempt to preserve fine details.

You can use a different power-of-two per side contrary to the WED tutorial on the WIki. You can use 2048x1024, or 512x2048 if you'd like. Pick a size that is suitable based on the original imagery in the file. If the original image was 4000x2000, you might want to use 2048x1024 as that maintains a similar aspect ratio in terms of pixel counts. You are free to use 2048x2048 if you want; but in this example, the original image only had 2000 vertical lines; so you're in effect stretching the imagery by 48 bytes.

Also ensure that the Conversion Process writes a Gamma value of 2.2 into the PNG file. This becomes important later on when trying to render the imagery within X-Plane. If your imagery is too 'washed out', try adjusting the Gamma value of your Images to 2.2, or 2.4, or 2.6 and try again. It's a bit of a balancing act - Getting a quality image without it being too washed out (not enough Gamma), or being too colour-saturated (too much Gamma). Consult your favourite Image Conversion tool on how to write a new Gamma value into a .PNG file. (I personally use GraphicConverter- http://www.lemkesoft...cconverter.html which is fantastic for this kind of thing)

Note that X-Plane only cares about the rectangle that the .POL file occupies. Meaning that even though my original GeoTIFF was 4800x3600, I can use a 2048x2048 image, and X-Plane/WED will stretch the image appropriately to fill in the entire area. You can also use a lower resolution for not-so-important areas. i.e. You can downsample to 1024x1024 or even 512x512. You will lose resolution, but the tile will still fill the entire defined area.

I frequently use 2048x2048 for high-detail (when you're generally close to the ground near airports), but drop to 1024x1024 resolution away from the airfield. I also use 512x512 for general draping of areas; where you are unlikely to be close to the ground; and more likely to be > 2000 ft AGL.

Remember, the lower the resolution, the less VRAM the imagery will occupy - Remember that not everyone has a 1 Gbyte VRAM Video Card! =) Size your imagery appropriately.

9b. Remove the GeoTIFF Overlays - The GeoTIFFs are no longer needed

Reload WED now.

You will immediately notice you now have TWO overlay images in WED. One will be the original GeoTIFF overlay, and the other will be the new .PNG image. (WED Automatically puts the new .POL files at the bottom of the hierarchy list on the top right side). You should now delete the original GeoTIFF overlay from WED, by selecting your original GeoTIFF overlays in the top right and removing them. You should now only have the .POL file imagery (the .PNGs) showing in WED.

Save your WED project.

10. Convert the PNGs into DDSs

This is the ultimate step in preserving VRAM and maintaining Image quality. Using XGrinder, convert the .PNG to .DDS format, so it's fast to load, looks good w/compression, and has a much smaller file size, suitable for distribution. XGrinder can be found here: http://developer.x-p.../tools/xptools/

If you want some more background on why you should use DDS instead of PNG, Ben posted some great comparison shots here: http://developer.x-p...-in-x-plane-10/

11. Export Scenery Pack.

Your /Custom Scenery/MyProject/ directory now should contain an "Earth Nav dat" folder, and inside will be a DSF file. This file tells X-Plane the location of where all your .POL files are (i.e. Tiles/image1.pol, Tils/image2.pol etc...), and where those polygons should be located in the world (lat/long dimensional size).

12. Delete any GeoTIFF and PNG files in your /Custom Scenery/MyProject/Tiles directory.

You have completed the process; and you no longer require the GeoTIFFs nor the PNG files anymore. Both X-Plane and WED knows how to read .DDS files directly; hence, prior to distribution of your scenery, you should delete these files in order to keep the distribution file-size down.

Congratulations! You can now .ZIP up your /Custom Scenery/MyProject/ directory, and upload it to the .ORG!

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Method 2: Using JPG files, as long as you know the coordinates.

Instead of using GeoTIFFs, you can use any other type of imagery, as long as you know the latitude/logitude of the corners of the imagery.

1. Download the imagery (in JPG, GIF, BMP format, etc..)

2. Convert the .JPG/BMP/other-format into .PNG.

Use your favourite photo-editing tool to convert the file into a .PNG; so that WED/X-Plane can read it.

3. Read the Above section (Method 1) in terms of creating a directory, loading the image into WED, placing it onto the world map, etc...

You should now have a .PNG image loaded into WED, and visible, but alas, since we lacked the GeoInformation - it did not snap into place. Hence, we need to:

4. Manually line up the corners of the tiles.

For example, one provider I use (nearmap.com) only sends out files in 100% quality .JPEG format; but includes a text file with each 'tile', which specifies the lat/long of the top-left corner. For example, I am given a series of tiles called 1-1.jpg, 1-2.jpg, 2-1.jpg, and 2-2,jpg. These represent 4 interlocking tiles. Each image also had a text file that came with the download, i.e. 1-1.jgw, 1-2.jgw, 2-1.jgw, 2-2.jgw, etc...

The last 2 lines of the ".jgw" file contains the top-left corner of the orthophoto in decimal LONG/LAT format

Here's an example of a 1-1.jgw file:

0.0000015352814587
0.0000000000000000
0.0000000000000000
-0.0000015352814587
151.1913925395580804
-33.9672906499639637

Top left corner of the 1-1.jpg image is +151.191, -33.967 (aka 151.191 East, 33.967 South)

I them used the 2-2.jgw file to discover the bottom/left of the 1-1 image (as all the tiles snap together.)

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Here's another example:

1-1.txt:

...
...
...
...
151.1505172060011546
-33.9201268035521437

This states that the top-left corner of this image is 151.1505 Longitutde (E) and -33.9201 Latitude (South). The last file says:

...
...
...
...
151.1536614624286017
-33.9232710599795979

Remember, all these files form a grid, so the top-left of one tile is the bottom-right of another tile. That based on all these lat/long coords I received, I can accurately place the corners of my imagery; by selecting each corner of my loaded overlay, and manually entering in the LAT/LONG that was given to me by the photo provider.

To do this, I manually select the corner of the polygon as such:



Using the Vertex tool, select one of the corners. On the bottom right, you can now paste in the information from the .jgw file.

(Use cut and paste from the .jgw/ text file - makes your life easy). You can also select multple verticies, if you know that they all share the same latitude, for example, and do them all at once by selecting a row of verticies, pasting in the latitude to the first one, and hitting [ALT]-[ENTER] when done. It will then change the LAT of all the selected vertifies at once (Thanks to Tom Kyler on this one - it's a new feature in WED he made a nice video about....- nice trick!)

5. Create Draped Polygons.

6. Export Scenery Pack.

7. Convert the PNG to DDS using XGrinder

8. Delete the .JPG and .PNG files.

9. ZIP up and upload to the .ORG =)

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Optional - Removing Water

Many times, imagery contains water; which you want to remove (make transparent), so that X-Plane's own water can be seen through it. This requires editing of the original PNG files, to add what is known as an "Alpha Channel" (transparency).

1. Load the .PNG image into your favourite Image Editor. (Win/Linux: use Gimp. MacOSX: use the built-in "Preview.app". Both can do Alpha Editing)

2. This example is using MacOSX's Preview.app (which makes this a 2 second job) Using the "Instant Alpha" or "Magic Lasso" or other such-named tool, select the water area, and hold down the mouse button; and slightly drag the mouse. You will notice that the water area now goes pink, but the shoreline doesn't.

3. Release the Mouse button, and hit [Delete]. The water is gone, but the land is still there.

4. Save As -> Save the new file in .PNG format, and ensure the 'Alpha' Checkmark is enabled.

5. Your new file now has a transparency for the water. Once again, use Xgrinder to convert it into .DDS

6. Replace your old .DDS tile with this new (Alpha'ed) .DDS tile and load X-Plane. You should now have water showing through underneath.

7. If you get X-Plane's own beige beaches showing through instead, instead of water (since X-Plane adds it's own beach area to shorelines and water areas):

- Use the Exclusion Zone tool in WED (the big red [X])
- Draw a rectangle (or series of rectangles) around your shoreline
- On the right side of WED, select exclude: [x] Beaches

8. Export Scenery pack, and now you should have no beaches showing through; and instead a nice clean/crisp shoreline between your orthophoto and the water.

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I will update this thread with some extra imagery in a bit (for more illustration) but wanted to get this out to all of you. Also let me know if you want other things discussed and/or added to this FAQ.

Cheers.

- Chris.

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EDIT: Additional USA Sources which i found in about 30 seconds of searching the USGS website.

http://eros.usgs.gov..._Available/DOQs
http://seamless.usgs.gov/hro.php
http://seamless.usgs...less/viewer.htm

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EDIT: A discussion on how to get lat/long coordinates out of a Google Earth Overlay to line up your buildings. Note that Google Earth Imagery is bound by copyright; and you may not use it in redistribution. However, you can use it in order to line up buildings/taxiways/etc... to reality.

http://forums.x-plan...ndpost&p=636681

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Editing filenames on the right side and a sample WED layout:


Here's someone made a nice photograph of all the possible textures in lib/airport/pavement/xxxxx.pol : (apologies to whomever originally created this.. (nickster?)..) You sent it to me one day, and it's been sitting on my desktop ever since! A great reference! =). Just re-sharing it here. Pls met me know who made this so I can attribute the correct credits.

[SwissCyul]

Wow.

 

At first a really big thank you to Chris!!!!

That is really detailed. I think i will need some time to read and understand this.

The question is hereby solved, i think 

 

Thank you very much!!!!

[john82088]

Thanks Chris - I always wondered how that was done.

John

[pryoski]

This will be my next step in my scenery creating journey .. thanks a million Chris for your very clear instructions!

 

I've managed to do a fair rendition of my home airport while exploring WED, now this will be the next step for me. Cheers, Kris.

[Colin S]

Holy cow... and to think that so much of this has become automatic for me now. Seeing as I just wasted hours of Chris's life figuring out how to use GeoJasper in terminal, I can't say I'm perfect and speedy at this stuff, but it makes me appreciate what is yet to be learned.