View Full Version : From FT to Terragen (Part One)

Greason Wolfe
01-02-2009, 01:50 AM
Fractal Terrains to Terragen Version 0.9.43

This is a process I've been fiddling with off and on for a while now and until just recently, I'd never had much success with it. Then I was struck by an epiphany and thought I'd share it with others who might have experienced similar frustrations trying to export FTPro results into Terragen. Before getting into the process, however, it is important to make sure you have all the software that will be needed.

Terragen (I'm using the uregistered/free version 0.9.43)
-Windows Version : http://www.planetside.co.uk/terragen/win/downloadwin.shtml
-Mac Version : http://www.planetside.co.uk/terragen/mac/downloadmac.shtml
TGPGuilib_v_1_2_7 http://homepages.ihug.co.nz/~jomeder/tgpguilib/index.html
For Export Only (which this tutorial is based on) http://homepages.ihug.co.nz/~jomeder/feo/index.html

You will also need two coloring schemes for FTPro (see attachments)

Your Preferred Coloring Scheme (mine is FT2TG.ltg)
TG-Greyscale.ltg (include as a zip file)

Once you have these installed, you'll be ready to begin.

There are probably more efficient ways to transferring results from FTPro into Terragen, but I've found that my approach is, perhaps, the simplest in terms of understanding what is happening between the two software packages. Rather than exporting FTPro results as a RAW or MDR file and trying to import those into Terragen, we're going to work with grey-scale images since, at least for me, they are more easily controlled and visualized. And that brings us to our first "difficulty."

Theoretically (although unrealistic), we can use up to 16 million colors to represent elevation in FTPro. The same holds true for Terragen to a certain degree, but with the math involved, it is much easier to take the grey-scale approach and work with 256 colors. The key is in distributing those 256 colors efficiently such that we have enough room to work with, particularly for elevations above sea level. And I promise, we are going to get to that in just a little bit. First, we need to get ourselves a world we like.

Typically speaking, when we generate a world in FTPro, we have some fairly straight forward parameters that we follow. For instance;

Highest Peak : 30,000 feet (9146 meters)
Lowest Depth : -30,000 feet (-9146 meters)
Circumference : 25000 miles (40244 kilometers)
Roughness : 0.54
Percent Sea : 70
Land Size : 2.67

There is, unfortunately, a problem with these parameters that isn't obvious at first, but I will do my best to explain it. Terragen works with two types of measuring units; Meters and Terra Units. I'm really not sure what Terra Units are supposed to be, but I'm sure we're all familiar with what Meters are, so we'll stick with them. The problem comes from our Highest Peak to Lowest Depth range. That's a lot of ground to cover, so to speak, and in Terragen this can cause quite a bit of exaggeration if we aren't careful. Fortunately, we can bias this range since we won't be seeing anything below the surface of the water in Terragen. (As a side note, there is a plug-in to allow for water transparency, but I haven't messed with it yet.) But we're going to need a few numbers;

1 meter = 3.28 feet
1 kilometer = 0.62 miles

Now, keeping in mind that we are limited to 256 colors in grey-scale, all of which we are going to use, we want to bias our elevation range such that most of those colors will be used to represent areas of our world that are above sea level which should, in turn, give us fairly gradual slopes when we import the results into Terragen. To that end, we first must define our elevations based on what we need and what we don't need.

What we need is a wide range of elevations above sea level since that is the part of our world that will be needing the most detail in Terragen. What we don't need is a wide range of elevations below sea level since they won't (for the most part) be visible as anything other than water in Terragen. We are going to do this by defining our overall elevation range as a percentage of the colors available to us. For the purposes of this tutorial (and the examples here-in) I went with 82 percent (210 shades of grey) representing elevations above sea level and 18 percent (46 shades of grey) representing elevations below sea level.

With that decided, the next thing we have to do is determine just how much elevation each of those colors represent as individuals. To get a decent amount of height to our world in Terragen, we're going to have to exaggerate things just a little bit. I went with 30 meters of elevation per shade. Doing the math, this gives us the following;

Highest Peak : 20664 feet (210 colors x 30 meters x 3.28 feet)
Lowest Depths : -4526 feet (46 colors x 30 meters x 3.28 feet)

(If you want higher elevations above sea level, pull a few colors from the Lowest Depths and add them to the Highest Peak value)

One thing we're going to need to know for rendering in Terragen is the circumference of the world. Leaving this at a standard of 25000 miles gives us 40323 kilometers. This will be important for scaling functions when working in Terragen. Conversely, you can use metric values in FTPro if you are more comfortable with them, the process is still basically the same and any differences should be fairly obvious.

Now we generate until we find a world that we like and want to work with. Of course, we'll need to set our Coloring Scheme.

At first, we can use any Altitude Coloring we want and adjust the parameters to represent that 82 to 18 ratio outlined above. We'll also tweak the shading slightly for some added texture when we start working in Terragen. The FT2TG.ltg file above is the color scheme I use for editing my worlds in FTPro and geared towards representing lowlands as forest and grasslands, low to mid-level slopes as mountains and all upper slopes as snow. It has already been adjusted to represent the 82:18 ratio and been tweaked for shading, but I would recommend using whatever color scheme you are most comfortable with as long as you can easily identify what elevation your mountains are starting at and what elevation will typically be snow covered on a year round basis. If you use your own coloring scheme, you'll need to make the following adjustments under Map>>Lighting and Color>>Altitude;

Colors : 210
Blending : Checked
Shading : Checked

Colors : 46
Blending : Checked
Shading : Checked

And under Map>>Lighting and Color>>Intensity, we'll set the parameters as follows;

Light Direction
Elevation : 43
Azimuth : 315
Vertical Exaggeration : 1.1
Shadows : Just above the N in None for a little added texture in Terragen

Then it is off to editing land until you get a look to the world that you are pleased with.

Part Two Coming Soon!!!

Greason Wolfe
01-02-2009, 01:07 PM
Okay, now that I've had some much needed sleep, I'm ready to continue. Of course, last night as I started this, I didn't even thing to offer the parameters I would be using for world generation so everyone could follow along directly. So, here they are;

Highest Peak : 22302 feet
Lowest Depth : -4885
Circumference : 25000 miles
Fractal Seed : 1923767461
Roughness : 0.54
Percent Sea : 70
Land Size : 2.67
Fractal Function : Wilbur Ridged Multifractal
Editing Size : Large
Projection : Equarectangular

That gave me the following results;

(see first image below since I can't seem to insert them inline in the post)

I'm not going to do any editing on this world, we can use it just as it is. All we need to do is find ourselves a nice island to work with in this tutorial. (Note : It doesn't have to be an island, but I'm going to use an island so that we can get a good elevation range). As it happens, there is a perfect island for the purposes of this tutorial located in the lower left quadrant;

(see second image below)

Now the fun begins.

Having zoomed in on the island, there are two things I am going to need at this point;

1) A grey-scale version of the island
2) A range for the area being viewed

Optionally, I can also pick up a colorized version of the island as well, but it isn't absolutely necessary to have that at this point. In any event, we'll need to load the TG-Greyscale.ltg coloring scheme at this point. And yes, there are going to be some very drastic changes on the screen.

Print Screen is my friend, and I use it a lot. In this case, I'm going to use it twice. Once to capture a colorized version of the island, and then, after loading the TG-Greyscale.ltg coloring scheme, once to capture a grey-scale version of the island. These, I am going to paste into my graphics editor as two layers in a single image.

The last thing we need is a range for the area being viewed. For that, all we need is View>>Map Info Window. The number that interests us here is the North/South Range. In this instance it is approximately 1690 miles (2726 kilometers). We need this for scaling purposes in Terragen.

Now, working with our captured images, we need to trim all the junk off of them and get a nice square version of the grey-scale image. This is where having the colorized version as an additional layer comes in handy since seeing the land masses in grey-scale can be difficult. The simple way to do this is with the Select Tool in your graphics editor. The important thing here is to make sure you get the full range of view from top to bottom, like so;

(see third image below)

Again, this has to do with the scaling in Terragen.

Once you've selected the area you want to work with, copy the grey-scale version of that area into a new image. This image should be perfectly square, if it isn't you'll have to try again. If you are following along with the tutorial directly, your results should look something like this;

(see fourth and fifth images below)

Now we need to prep our image for use in Terragen.

This is a fairly straight forward thing. We want our image size to be 513 by 513 pixels (the largest that an unregistered version of Terragen can work with). So we'll resize as necessary. Then we want to make the image true grey-scale. Most graphic editors these days have a one-click feature for that usually under the Color Menu Drop-down. And then we need to save the image as a .bmp file.

And now we're ready to start working in Terragen. To save time, you can copy the grey-scale image above and use it in Terragen.

Greason Wolfe
01-02-2009, 02:35 PM
Assuming you've installed Terragen (0.9.43) and the requisite plug-ins as listed above, let's get that started up and set-up our editing area.

Once you've started Terragen, you should see three things;

1) The main application window
2) The Rendering Control window
3) The Landscape Window

We're going to start by clicking on the Size button in the Landscape window. This should bring up the Landscape Settings window. If, like me, you are using an unregistered version of Terragen, the maximum Landscape size you will be able to work with is 513, so we'll click that button and agree to use more memory for rendering. We'll also tell Terragen to keep the terrain flat for now.

Now we are going to need that range information we captured earlier. Your Landscape Settings window should now look like this;

(see first image below)

We need to adjust the point spacing. We could do a little bit of math for this, but the easiest way to get this adjustment is to insert our range value into one of the two Quadrant boxes. In this instance we need to convert from Kilometers to Meters which gives us a result of 2726000 meters. This is very important. Smaller values tend to result in very exaggerated elevation results like so;

(see second image below)

Not exactly what we were looking for. So lets make sure we get that setting adjusted.

Now we need to import our grey-scale image. We're going to do this through Landscape>>Accessories>>F.E.O. - Windows Bitmap Inflator. This will open a directory listing and allow you to select the grey-scale image for rendering. Once you've opened this image, a new Dialogue will appear. It gives you the option of calculating elevation settings and that is exactly what we want to do at this point, so we'll click the Calculate button.

If you look in the upper left portion of the Calculator Window, you will see an area called Pixel Values. We are going to need these two numbers since they represent the darkest and the lightest shades of grey in the image. In this case, our darkest shade is 19 while our lightest shade is 115. We're going to save those values for later use. For right now, however, you can click on the OK button here and in the previous window.

At this point, there are a number of little things we need to do. First, lets set our water level at 0 meters. Next, we're going to modify our elevations. We do this through the Modify button in the Landscape window.

Using our numbers from the calculator we start with our lowest level. This particular grey-scale image is set for a sea level at a shade of 45, so that gives us 26 shades (45-19=26) that are below sea level. Multiplying this number by 30 (remember we defined each shade as being 30 meters of elevation) gives us 780 meters. Next we will work with the highest peak. In this instance that will be 2100 meters (115-45=70 70x30=2100). We'll plug these number into the Set Height Range section of the Terrain Modification Window and click Set Height Range.

It is a good idea, at this point, to go back to the Size button on the Landscape window and make sure our numbers there haven't changed. If they have, reset them to the proper values (2726000 meters per quadrant) and then go back to Modify and make sure our Height Range hasn't changed. Again, if they have, set them to -780 and 2100 respectively and click Set Height Range again. (There is a small bug that sometimes crops up here and causes these numbers to change so double checking them as we go along is always a good idea)

Now lets take a look at our results. Because of the area we are looking at, to get a good overall view, we are going to have to elevate our camera considerably. I used an elevation of 300000 meters and pointed the camera almost straight down to render the following image;

(see third image below)

For this image, I used the GrassandSand surface that is included with Terragen. It doesn't do a very good job of showing the elevations, but there are a number of free surface files available for Terragen if you do a web search for them. Alternatively, you can develop your own surfaces (for which there is a most excellent tutorial in pdf format available from http://www.planetside.co.uk/terragen/smgdl.shtml).

But that, for the most part, is it. You will probably have to play with the settings some and, if you have a registered version, you can always use larger sizes for both the grey-scale image and the editing in Terragen.

As a brief side note, I hacked this tutorial together in a relatively short period of time in hopes that it would get those of you interested in using it started in the right direction. I have every intention of re-writing this tutorial with much clearer language and many more examples in the future and will make it available as a text file for those of you that are still interested in using it. Hopefully, however, there is enough information here to get you started such that you can figure out the little details on your own. If there are any immediate questions, feel free to post them here or PM me and I will get back to you as soon as possible.