What is Terragen?
Terragen is a powerful application dedicated to rendering and animating natural environments both highly realistic and fantastic. It represents more than a decade of focus on algorithms that plausibly simulate skies, outdoor lighting, terrain textures, clouds, and large and detailed landscapes.
Terragen is not designed as a general-purpose renderer. Though it is possible to use it to render buildings, indoor scenes, and arbitrary objects of any kind, it is not the best tool for these tasks, nor is it intended to be.
For the hobbyist, Terragen provides the ability to create beautiful and convincing images of landscapes both realistic and fantastic. Rendered output can be used as-is, or combined with photographs and output from other 2D/3D applications to create a final image. With the level of quality Terragen provides for landscape-specific scenes, renders can often be printed or posted online without further adjustment; its results easily stand alongside photography or output from other 3D applications.
For the professional, Terragen fits cleanly into an existing production pipeline with import and export of terrain and animation data to industry standard formats, and full support of high dynamic range throughout the rendering pipeline for accuracy, quality, and solid integration with other elements. It is expected that most production-level output will be created in combination with other applications as part of the artist's normal workflow. Applications that have strong object modeling and rendering functions would ideally be used for critical foreground object rendering, for example, while a compositing application would combine these and other elements with live action or animation to create the final output.
Terragen is a foundational product upon which greater capabilities and functionality will be built. As it develops, the Terragen product line will remain focused on landscape modeling and rendering, and functions and features which are added will be aimed specifically at supporting this focus. Our passion is terrain, so Planetside Software's primary goal is to excel in this area, leaving other areas such as object modeling and character animation to applications dedicated to those tasks. We strive to work with other applications effortlessly and cleanly, allowing each application to focus on its strengths.
In Terragen, every scene is built in the context of an entire planet. While you may not always use this vast scale in your scene, the realism provided by this planetary context, including a properly curved atmosphere, will contribute to the quality of any scene. With the advantage of procedural displacement and texturing, you can achieve scenes from centimeter scale all the way up to a whole planet and beyond, all with consistent and realistic terrain forms and textures.
For many scenes, your focus will only be on a small area. The planet upon which you're building your scene won't affect your process that much, so you can often just ignore the area outside your scene. Having the planet as a background ensures that the scene doesn't just “end,” nor does it just go on forever as it would with an infinite plane. Instead it always curves realistically down to the horizon. Of course you can always use a separate plane if your intention is actually to achieve that look of “infinite flatness.”
The planet context comes into its own when you're building really large scale scenes. Terragen can realistically depict one or more planets from space, with highly realistic atmospherics and lighting.
Even your average high mountain scene can also benefit from the same sense of scale, with the ability to place terrain elements and vegetation from foreground to background, all the way into the distance tens of kilometers away. From the top of Mt. St. Helens you can often see over 50 miles to Mt. Rainier for example, and proper depiction of scale and distance is vital for realizing a scene like this:
Literally, to change the position of something. In graphics terminology to displace a surface is to modify its geometric (3D) structure using reference data of some kind. For example, a grayscale image might be taken as input, with black areas indicating no displacement of the surface, and white indicating maximum displacement. In Terragen 2 displacement is used to create all terrain by taking heightfield or procedural data as input and using it to displace the normally flat sphere of the planet.