Author Topic: Is real world data improvement a possibility if so which version do i need?  (Read 2368 times)

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TJTAS

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Basically what i want to be able to do is import data which is srtm 90m data which has been re-gridded to 12.5m. Then use the tools in WM to apply some "extra" detail and then export back to the same resolution.
The resolutions i am dealing with would be up to 6400 x 6400 points. The SRTM has been imported previously in UTM format so the grid elements are square.
Is this possible within WM and which version would i need to buy.
« Last Edit: November 09, 2014, 05:28:18 PM by TJTAS »

Remnant

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Hi there,

This is absolutely possible, the one caveat that must be noted is that WM is not geo-aware and cannot re-interpret projection information, etc. However, so long as you understand that you are essentially taking in raster data, working on it, and exporting it back out, everything works great.

Any edition of World Machine can work for this application; 6400x6400 is a completely reasonable resolution to work with. The main difference between the Standard and Pro editions in this case will be speed; the Pro edition can use many threads to help speed things up on a multicore processor, while the Standard Edition is limited to 2 cores.

If you already have downloaded the Basic Edition to experiment (which I recommend), In the Examples folder there is an example setup already for doing this (take coarse real-world, add fractal noise and erosion, export height and create texture maps) called "New Examples for 2.3\Techniques\Improving Real World Terrain.tmd"
-- Stephen Schmitt
- Creator of World Machine

TJTAS

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Thank you for the information. I understand the caveat and that is precisely what I want to do. The map format I am working with already has the geo-data embedded. I have the ability though to import/export this data into any format i want as long as i maintain a 1:1 parity with the original grid.

I guess this is my concern having been experimenting with the Basic edition. I can't seem to work out how I load the data to establish this in-out parity. I have tried to load a sample set which I exported from SRTM directly. When I load that through the input data device its default is to try and map that to the currently selected area which is obviously 512x512 for the basic edition. I then have to try and guestimate the scaling to establish the final grid spacing I want. With the standard edition can I set that grid to be 6400x6400 at the start and then directly load my grid into it?.

I am really impressed so far with the speed and quality of the effects in this program.

Remnant

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World Machine separates the idea of resolution and world size. Your input file is by default mapped to the same region as is being covered by the default viewport, which happens to be mapped to 512x512 pixels as that is the resolution limit of the basic edition. however you can set that region to equate to any number of pixels and/or space you wish, including the same or more as the input file.

You can just load the file in, set the resolution to what you want, and go to town. However, I would highly recommend going a bit further to tune things:

World Machine tries to equate the pixel spacing to real-world units. On a gross level, the world size doesn't matter, really -- most of the effects and algorithms are actually scale independent. However, being able to view your data in proportion is critical to actually tuning the effects. The easiest is to work with WM in this. You know the actual bounding extents of your dem data in the real world in meters; if you inform WM of this, you can get correct proportions. If you do not, most everything will actually operate correctly, but the scaling of the viewports will be all wrong, and you will be mislead in all kinds of important ways.

Workflow would be:

0) Create a file input device and open it
1) Select and load your datafile
2) Set file world region (X/Y extents) to match real world extents
3) Click "Adjust Current Extents", which will set the viewport to exactly match the current file region.
4) In the Altitude Scaling box, you will probably need to set your file elevation mapping to the approximately correct values as well.

Your DEM should now be loaded and in proportion. If you go into the Layout View, you can zoom in and out on any region of your DEM, set a smaller viewport that is only looking at a particular part, etc.

To build and export the whole map at any resolution, you would make sure your viewport is viewing the whole file region, then simply set the resolution slider in the project settings dialog.

« Last Edit: November 10, 2014, 02:54:04 PM by Remnant »
-- Stephen Schmitt
- Creator of World Machine