View Full Version : Terragen 2: Creating a basic landscape

Aragon Speed
08-05-2007, 02:32 AM
When I switched on my PC today, I remembered that I had downloaded the technology preview of Terragen 2. So I thought I would share the progress of creating a basic landscape from scratch to completion with you in a series of renders taken at each stage of the process.

For anyone who is not familiar with this program, it is a program designed to render high quality landscapes ranging from local areas right up to full planets. The technology used in Terragen 2 is based on the same planet construction and rendering engine used to create the planet scenes in Star Trek Nemesis.

Regulars to the forum will know that I have used the original Terragen for a while, but that this program, while still good, is getting a bit long in the tooth now. For examples of what the original Terragen was capable of, have a look at the two landscapes I did for the graphics competition here: http://www.thexuniverse.com/viewtopic.php?t=2945&start=0&postdays=0&postorder=asc&highlight=
I suggest you have a good look at these two pictures, as they will give you a good basis for comparison between Terragen, and the awesome power that is Terragen 2.

Right back to Terragen 2. First there is one thing you must be aware of. This is a technology preview, which means it is showing off the power of the program, but it is not yet complete, and has some limitations compared to the full program. (Which is also not yet complete or released.)

Some of the limitations are:
You can only render images at a maximum resolution of 800x600.
AA settings are limited to 3xAA.
Detail settings are restricted.
The water module is limited to only producing lakes.
The vegetation (Flora) module is completely missing.

Even with these limitations, you can still get some amazing results.

During this wander through the landscape creation process, I will refer to Terragen 2 as TG for ease of writing. All pictures here are renders and not screen grabs or previews.

OK Lets get to the pictures.

When you first load TG you are presented with a completely flat, grey, featureless landscape. The world in TG is based around a full globe, which starts out completely smooth.

Flat landscape (http://downloads.thexuniverse.com/Aragon_Speed/TG2/Flat_landscape.jpg)

There are a lot of different ways to generate landscape features in TG. I’m going to use a couple of different ones here at the beginning so you can get a general feel for what is possible.

Right lets add some ‘terrain’ to our terrain. In the next picture I have applied a heightfield generator to the landscape. I have used the standard settings and not tweaked it for a custom look in any way.

Heightfield generated landscape (http://downloads.thexuniverse.com/Aragon_Speed/TG2/Heightfield_generated_landscape.jpg)

Lets move the camera and find a more interesting view down amongst the newly created landscape.

New camera position (http://downloads.thexuniverse.com/Aragon_Speed/TG2/New_camera_position.jpg)

You can already see that by applying a simple heightfield generator, which takes about 20-30 seconds, and moving the camera, the landscape already looks more detailed and realistic than the original Terragen could ever hope to produce.

Now let’s get a different perspective on our scene.

Zoomed out (http://downloads.thexuniverse.com/Aragon_Speed/TG2/Zoomed_out.jpg)

By zooming out you will notice that the mountains end abruptly in the distance. This is fine if you stay hidden within the mountains we have just created, but it’s clear there are limits to the heightfield we have created. What of the promise of full planets? This is where procedurals come in and if we want an endless horizon of terrain, they are the best way to achieve it. You can also use more than one heightfield or increase the size of your heightfields, but neither are optimal options. Lets move on to creating a global terrain.

By disabling the heightfield we end up back at a flat terrain.

Back to flat (http://downloads.thexuniverse.com/Aragon_Speed/TG2/Back_to_flat.jpg)

I shall now apply a procedural technique called ‘Power Fractal’.

Power Fractal terrain (http://downloads.thexuniverse.com/Aragon_Speed/TG2/Power_Fractal_terrain.jpg)

The ‘Zoomed out’, ’Back to flat’, and ‘Power Fractal terrain’ pictures were all from exactly the same camera position.

By tilting the camera, you can now see that the terrain now runs all the way to the horizon.

Tilted camera (http://downloads.thexuniverse.com/Aragon_Speed/TG2/Tilted_camera.jpg)

So what are the coverage limitations of this type of landscape generation? Let’s zoom out and see.

Extreme zoom out (http://downloads.thexuniverse.com/Aragon_Speed/TG2/Extreme_zoom_out.jpg)

Of course at this range there is not much detail, but I think that answers that question. This is the power of procedurals.

Now that we have a terrain covering our world we need to give it some more interesting colours and textures.

I have zoomed in again and found a camera position that will give a good range of lighting, detail, atmospheric, and texture variations.

Pretty good position (http://downloads.thexuniverse.com/Aragon_Speed/TG2/Pretty_good_position.jpg)

In TG surface mapping is accomplished using “shaders”. “Shader” is a general term for nodes which generate or manipulate data that can then be interpreted as colour, displacement, etc. This shader data is used to create features in your scene such as surface texture and colour.

Right lets add a base colour. I’m going to use a brown to simulate dirt.

Base colour (http://downloads.thexuniverse.com/Aragon_Speed/TG2/Base_colour.jpg)

You build up the landscape using surface layers. Each surface layer when first applied defaults to all white with 100% coverage. In the next picture I have added the first surface layer, this will become the grass layer, but at the moment it is still at the default values. Mmmm Snowy. :)

First surface layer (http://downloads.thexuniverse.com/Aragon_Speed/TG2/First_surface_layer.jpg)

I adjusted the colour to a dark yellowey-green to approximate the colour of grass.

Adjusted grass colour (http://downloads.thexuniverse.com/Aragon_Speed/TG2/Adjusted_grass_colour.jpg)

As we all know, grass will not grow above a certain altitude. So the next step is to limit how high up our mountain slopes the grass will grow by switching on the ‘Max Altitude’ modifier for this surface layer. Looking at the next couple of pictures you can see the blending and shading of the altitude modifier at work. In the centre-right of the first picture you can see a very green patch of grass. This area is a valley, and as such is perfect grass growing country. In the foreground the grass has a slight browned look to it. The grass in this area being closer to its altitude limit causes this, and the brown dirt from the underlying base colour is staring to show through. Finally in the background you can see that the mountain has no grass on it at all.

Here are two pictures demonstrating this. The first one has the atmosphere rendering turned off so that you can clearly see the shading of the altitude modifier. The second has it turned back on.

Altitude limited grass no atmosphere (http://downloads.thexuniverse.com/Aragon_Speed/TG2/Altitude_limited_grass_no_atmosphere.jpg)
Altitude limited grass (http://downloads.thexuniverse.com/Aragon_Speed/TG2/Altitude_limited_grass.jpg)

Just as altitude affects where grass will grow, so does how steep the land is. You never see grass growing on vertical surfaces, you may see it growing in nooks and crannies in a vertical surface, but never on the surface itself.

Here I’m going to turn on the max slope modifier and adjust it to a basic 45 degrees so that the grass won’t grow on terrain that is too steep.

Slope modifier on (http://downloads.thexuniverse.com/Aragon_Speed/TG2/Slope_modifier_on.jpg)

Ok, lets add another surface layer for snow. This time it will have the ‘Minimum altitude’ Modifier turned on, again it has the max slope modifier on, and I have adjusted the pure white to include a hint of blue to give it the correct tonal values.

Snow Surface layer (http://downloads.thexuniverse.com/Aragon_Speed/TG2/Snow_Surface_layer.jpg)

Now its time to move on to the atmosphere. First we need to adjust the light so we can test any atmosphere and cloud changes in the proper lighting environment. The standard settings have the suns light set to a pure white. Unfortunatly the sun isn’t white. So I will add a faint trace of yellow to correct tonal values in the picture.

Added yellow (http://downloads.thexuniverse.com/Aragon_Speed/TG2/Added_yellow.jpg)

I am also going to move the sun to create slightly more shadow.

More shadow (http://downloads.thexuniverse.com/Aragon_Speed/TG2/More_shadow.jpg)

I feel that the atmosphere is a little to hazy so I am going to reduce it slightly.

Less haze (http://downloads.thexuniverse.com/Aragon_Speed/TG2/Less_haze.jpg)

The sky looks quite boring at the moment, so lets add some mid-level altocumulus volumetric clouds.

Clouds (http://downloads.thexuniverse.com/Aragon_Speed/TG2/Clouds.jpg)

As you can see the clouds automatically cast shadows on the landscape. I don’t like the standard clouds, they are too thin and look like they have been added afterwards rather than actually being a part of the scene. To add a small bit of drama to them I’m going to increase the thickness of the clouds.

Thicker clouds (http://downloads.thexuniverse.com/Aragon_Speed/TG2/Thicker_clouds.jpg)

And that is how to create a basic scene in Terragen 2.

08-05-2007, 03:04 AM
That's amazing!
What export options does it support?
I'd love to create some X3 goodies with this.

Aragon Speed
08-05-2007, 03:45 AM
None in the tech preview, but the main program is supposed to have quite an extensive list.

There is a Max plugin to read the Terragen 2 file format tho.

I'll go and find it for you.

Edit: Can't find it now I'm looking for it. :roll: When I come across it again I'll post a link.

08-05-2007, 06:50 PM
It would be interesting to have a look at the planet zoomed out again now that you've put all the grass and snow onto it. Looks absolutely fantastic though! I'm sure you've been finding some good combinations of lanscapes with that :)

08-05-2007, 07:30 PM
Looks great AS!! I'm wondering what more Terragen2 has to offer;

Can you add plantlife, prefab buildings, infrastructure and stuff?
Can you animate a camera and render a movie flying over the landscape?
Can you add more admospherics, rain, fog, snow, draft, etc?

Aragon Speed
09-05-2007, 04:05 AM
Can you add plantlife, prefab buildings, infrastructure and stuff?
Yes, TG2 has an extensive import filter list (Even in the tech preview), including .obj so any thing you export from max or poser in that format can be imported into TG2. TG2 also supports all of the XFROG vegetation, and also will have quite a large library of vegetation built into the final product.

I am working on a scene at the moment that includes some real vegetation, rather than just the green surface layer that I used in this basic introduction.

Looks great AS!! I'm wondering what more Terragen2 has to offer

Following on from what I was saying above, plus what you have said in your post, you might want to go and have a look at the pictures on this page that the alpha testers have created. They (obviously :) ) have access to the latest full build.

Can you animate a camera and render a movie flying over the landscape?

Yes. Take a look at this (http://www.planetside.co.uk/terragen/tg2/mars_v14.mp4).

Can you add more atmospherics, rain, fog, snow, draft, etc?

Not entirely sure. Two reasons for this, 1 I'm still learning this program, it is much more versatile than the original Terragen was, and thus much more complex. 2. This is only a tech preview. They haven't finished making TG2 yet, the last I heard they where working on a volumetric water system. :jump:

You can certainly add more cloud layers and different types of clouds, and your options for changing them into what you want are quite extensive.

For anyone wanting to have a play with the tech preview, you can get it with the link at the bottom of this (http://www.planetside.co.uk/terragen/tg2/tech_preview.shtml) page. There is also a link next to it to get 5 free XFROG plants to use in your renders. (five plants at three different growth points (ages) = 15 models)
There are also some nice tutorials for the tech preview here (http://forums.planetside.co.uk/index.php?topic=110.0)

I expect to see some entries in the next GFX competition people.... :wink:

Aragon Speed
09-05-2007, 05:41 AM
Here is a link for a TG2 tools page.
I haven't had time to check it out, but looks familiar. Might be the page with the importer for max. Or perhaps for importing max stuff into TG2. Either way it might be helpful until the full version of TG2 is released with it's full compliment of import/export filters.