Migrating from TG 0.9

Started by old_blaggard, December 14, 2006, 06:18:24 PM

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Migrating from TG 0.9 by Old_Blaggard


   Terragen, since its inception, has been a wonderful program with powerful atmosphere and surface shaders, support for large heightfields, and a very realistic water system.  However, one of the things it is most well known for is its relatively simple GUI.  Many who would be intimidated by an application like Vue or Mojoworld manage to find in Terragen a simple, straightforward, yet powerful method of creating their landscapes.  With the vastly increased functionality, realism, and control of Terragen 2, the interface has become much more complicated - but not necessarily harder to understand.  The purpose of this document is to review the basic similarities and differences between the Terragen and Terragen 2 interfaces in order to make the transition to the new version smoother.  We will proceed through the various windows of Terragen 0.9 and find the comparable windows and functions in Terragen 2.

Brief Overview of Terragen 2 Interface

   The basic screen of Terragen 2 is divided into five parts.  Along the top is a series of buttons that do various things such as opening and saving projects.  They are followed by a list of tabs, reading, from left to right, Objects, Terrain, Shaders, Water, Atmosphere, Lighting, Camera, and Renderers, and Node Network.  Each of these, when clicked, will bring up a list of their associated nodes.  These nodes appear in the upper left section of the window.  When selected, the node’s settings will appear in the lower left section of the window.  Our last two sections are the 3D realtime preview in the upper right, and the node network in the lower left.  In this document we will not be delving very far into the node network, as it is the aspect of Terragen 2 that is most different from Terragen 0.9, and because detailed knowledge of it is not required to make basic images.

Rendering Control

   In Terragen, the Rendering Control Window allows you to render previews, set up your final render settings, adjust the quality, and position the camera.  In Terragen 2 this is separated into two parts.  First, click on the Rendering tab.  There are by default two nodes - a Quick Render and a Full Render.  Select one of them, and you will see that the controls are much more advanced.  You can set the quality, image size, and crop images among other things.  In order to position the camera, you have to click on the Camera tab and select the Render Camera node.  Here you can set the position of  the camera.   This is done by setting the x- y- and z-axis coordinates relative to the default center point, at which the camera always starts.  Be aware that depending on the position of the camera on the planet, an increase in y-values, usually associated with gaining height, may not result in a height increase.  Heading, bank, and elevation are controlled below the camera position.  These are relative to the camera’s position above the terrain; not to the center point.  Finally, you can also adjust other settings in the camera node such as motion blur.


   The landscape window in Terragen is where you generate the heightfields used as a terrain.  In Terragen 2, all things terrain are controlled through the Terrain tab (surprise!).  Here you can generate heightfields or fractals that are added to the terrain.  Simply click the “Add Terrain...” button and choose what type of fractal or heightfield you want, and then tweak it according the to type of features you want.  In this sense generating terrain is fairly similar to generating them in Terragen 0.9; the differences start to appear when one gets more in-depth into changing the fractal settings, their distributions, and combining terrains.
   In Terragen, you also manage surface mapping through the Landscape window.  In Terragen 2, this is done through the Shaders tab.  Terragen 2 surfacing operates in much the same way as Terragen 0.9 in that there are parent layers and child layers.  In Terragen 2, however, the coverage and distribution has much more control.  There are also traditional surface layers with height and slope constraints, and surface shaders, which apply a specific effect such as fake rocks or reflectivity to a terrain.  To add a surface layer or a shader in Terragen 2, simply look right above the node list, where you will find the Add Layer button.  To the right of the Add Layer button is the Add Child Layer button, which adds a child layer or shader to the currently selected surface layer.

Landscape - View & Sculpt

   This window allows you to pick a point of view on the heightfield and allows the user to do some basic sculpting.  In Terragen 2, there are no sculpting tools at this moment: sculpting often results in awkward and unrealistic terrains.  There is also no direct substitute for the large view of the terrain, except for a small window that appears between the node list and the 3D preview in the Terrains tab.  The 3D preview is probably the best way to find points of view and position the camera in Terragen 2 at this time.  Make sure that after you make a move in the preview window that you click “Set Camera” in the lower left of it to actually transfer the coordinates to the camera.


   The water window in Terragen 0.9 allows you to manipulate all of the settings pertaining to water, from the level, wave properties, transparency, and reflectivity.  The water tab in Terragen 2 allows you to create and define a body of water.  Click on the Add Water Object button above the node list and select Lake (the only option).  While the controls of the appearance of the water are very similar to those of Terragen 0.9 (wave roughness, patches, reflectivity, and transparency), you have much greater control over where your water appears.  Each lake is a circular body of water for which you can set the center, the radius, and the water level.  You can have multiple lakes on a planet, each of them at multiple levels.


   This window allows you to generate clouds, choose their color, and modify their density and coverage.  To create clouds in Terragen 2, a cloud layer is added by selecting the Atmosphere tab, and clicking the Add Cloud Layer button located just above the node list.  There are a number of presets available.  The clouds themselves are highly customizable, but some recognizable options are Cloud Altitude, Cloud Coverage (similar to Density Shift in Terragen 0.9),  Cloud Density (similar to Density Contrast in Terragen 0.9),  and Cloud Depth (Depth/Thickness in Terragen 0.9).  There are of course many more options, such as coloring, lighting, and quality.  Terragen 2 can support multiple cloud layers, and adding another is as simple as clicking on the Add Cloud Layer button again.


   The Atmosphere window in Terragen 0.9 allows you to change the parameters of the Haze, Atmospheric Blue, and Light Decay / Red.  In Terragen 2, Haze still exists, and Bluesky is analogous to Atmospheric Blue, as is Redsky to Light Decay.  In order to modify these settings in Terragen 2, click on the Atmosphere tab and select the atmosphere node.  In addition to everything you can do in Terragen 0.9, you can modify some of the lighting, change the render quality, and apply various tweaks.

Lighting Conditions

   In this window you modify the sun’s position, brightness, appearance, shadow lighting, and atmospheric glow.  In Terragen 2 this is done through various nodes attached to the Lighting tab.  By default there are two nodes: Sunlight and Enviro light.  The sunlight node controls everything that relates to the sun.  There is actually little here that cannot be done already in Terragen 0.9.  The major variation from Terragen 0.9 is the way the sun is positioned; the heading is determined from the center point, so if you move your camera more than a few kilometers away from it, the heading will begin to seem inaccurate.  The Enviro light node helps lighten the shadows and add faint tinges of color to the landscape - similar to the Background Light tab in Terragen 0.9.  You can also add fill lights, which can be used to selectively light up shadows.  Note: Enviro light adds a whole lot of time to a render with occasionally little effect.  If there aren’t many shadows visible in your scene and you are on a slower computer, uncheck the “Enable” check box, thus disabling it and cutting your render time down to anywhere from half to one fourth the time with Enviro light enabled.

3D Preview

   The 3D Preview window in Terragen 0.9 lets you navigate around the terrain.  That in Terragen 2 does essentially the same thing, but with more detail to the terrain and lighting.  While in Terragen 0.9 surface and water colors are fixed, Terragen 2 accurately reflects the conditions of the scene, albeit at a lower detail than a full image.  To tilt the camera around, hold alt and the left mouse button and drag the cursor around.  To raise and lower it, hold alt, your middle mouse button or both the left and right mouse buttons,  and drag the cursor.  To move backward or forward, hold alt, the right mouse button, and drag the cursor.  When you have found a point of view you like, click Set Camera; otherwise your render will be taken from the original camera settings.  To return to the current camera, click View Camera.  Both of these buttons are located right below the 3D Preview.


   There is no window in Terragen 0.9 corresponding to this Terragen 2 tab because it is an entirely new feature.  The object section is where the planet, the background, and imported objects are managed.  By default there are two object nodes in this section: background and planet 01.  In order to add more objects, select the “Add Objects...” button above the Objects node list.  If you want to add a single object, such as an individual tree or building, choose “Object.”  If you want to create a population of objects, select the “Population” option.  You will then see a list of many different options - you can use some of Terragen 2’s internal rock and grass generators, or you can import external .obj and .lwo files by choosing those respective readers.

The Node Interface

   Much ado has been made about the node interface on Planetside’s website, and its difficulty has been discussed extensively in forums.  However, the concept is fairly easy to grasp.  Those who have worked with World Machine or other programs that use node-based interfaces will find this one relatively straightforward.  Essentially, it is a series of functions, some layered on top of each other and some working in parallel.  The terrain nodes are used to calculate the surface nodes, which in turn are applied to the planet object, to get a final texture.  The cloud layers also feed into the atmosphere node, which then feeds into the planet object.  The camera gives information to the renderers.  However, for those who find this difficult to work with, it is possible to unlock almost all of the features of Terragen 2 using the tabs previously described above.

What now?

   This document only gave a brief overview of where the settings in Terragen 0.9 were moved to.  In the process it also provided you with a very brief picture of how the interface of Terragen 2 is set up.  However, it did not go into much detail on what Terragen 2 is now capable of.  I would now recommend reading the main documentation (which will walk you through your first scene with Terragen and describe many of the features more completely) or, if you are interested in learning more about the node interface, the node reference manual.  With the information you have here, you can probably also go on to creating your first images.

Good luck!
http://www.terragen.org - A great Terragen resource with models, contests, galleries, and forums.

Harvey Birdman

Many thanks, Old_Blaggard. That was a huge help. The only suggestion I would make is to move the discussion of the 3D preview and navigating within it to the very top. Personally, the very first thing I did was click on the 3D preview and try to rotate the image. I suspect others may react the same way. I was getting a bit frustrated before I came to that section in the tutorial. It's a very unusual mouse interface, and while I have a very common Logitech mouse, I had to switch to the 2-button interface to get things to work correctly. You may want to mention the existence of the mouse settings in Preferences as well.


Thanks very much, very useful for a very beginner in TG2, as I am, in spite of my english rather... well... weak.
Merci beaucoup


I am a "newby" too. While I have played around with T.09, I like T2 better and would like to be more accomplished than I am. I am 76 yrs young and need something to keep my mind active.
Firstly, I seem to have difficulty with X Y Zs. In the 3D view, does putting the cursor on a mountain or valley tell me the height of the terrain or is that the height of the camera?
Secondly, how do I prescribe a certain height to a terrain when creating a fractal terrain.
I have read many posts and tutorials and am still confused.


I am a "newby" too. While I have played around with T.09, I like T2 better and would like to be more accomplished than I am. I am 76 yrs young and need something to keep my mind active.
Firstly, I seem to have difficulty with X Y Zs. In the 3D view, does putting the cursor on a mountain or valley tell me the height of the terrain or is that the height of the camera?
Secondly, how do I prescribe a certain height to a terrain when creating a fractal terrain.
I have read many posts and tutorials and am still confused.
PS.. I'm not sure if this is posted properly.


Hi Normhol,

I recommend you post your questions in our main Terragen 2 discussion area or in the support forum here:

- Oshyan