First look at Terragen 4

First look at Terragen 4 It has been more than a year when Planetside Software, the leader in high quality landscape visualization, released an update for Terragen 3 updating it to version 3.2. What is Terragen? Terragen is a complex software solution for generating realistic landscapes, skies or other natural environments. The render capabilities were already tested in blockbusters like Star Wars: The Force Awakens (yes, the new one), TV shows, games, VR environments, museum exhibits, documentaries, and more. At this moment the company is preparing a new major release of Terragen 4 making the software faster, more interactive and easier to use. So far Planetside unveiled just some of the features and enhancement present in the next version together with some pre Alpha images and videos, but it looks that the preview features presented by the company are more than impressive.


Ray-traced real-time preview

One of the new features included in Terragen 4 is a ray-traced real-time preview with progressive refinement. The ray-traced preview mode supports Terragen shaders, lighting, and atmospherics, including clouds with volumetric shadows (aka “god rays”). This includes also the work with complex cloud and lighting setups. In all cases the ray-traced preview gives quick and responsive feedback, allowing you to iterate faster than ever before. We think this will revolutionize the way you use Terragen. Check the preview videos bellow:


New lighting model for clouds

Next to this, Planetside is developing a new lighting model for clouds that simulates multiple scattering without using the GI cache. In the real world, large, dense clouds of water droplets scatter light many times, absorbing almost none of the light as it is scattered. This gives rise to phenomena such as bright cloud centers that contrast with dark edges (especially when the sun is behind the camera) and inter-reflections between masses of cloud at scales both large and small. Light reaches deep into the shadows and beautifully illuminates the clouds in ways that a single-scattering simulation does not.

Thin clouds are easier to render because they can be approximated with only one scatter (because most light exits the cloud after the first scatter). But if we try to render optically dense clouds with only single scattering then not enough light reaches deep into the shadows and it’s difficult to consistently achieve all of the subtle effects that make clouds look like clouds. Most renderers try to approximate these effects in ways that often fall short of producing photo-realistic results. Terragen Classic had a simple ‘darkening’ parameter to artificially control the rate of self-shadowing, which became ‘light propagation’ in later versions. Terragen 2 added cache-based GI, which simulates multiple scattering but often lacks detail. To render many different kinds of clouds photo-realistically, we need a lighting model that works for large and dense clouds as well as for thin ones, whether wispy or smooth, and everything in between.

The new model in Terragen 4 produces the bright centers and dark edges that we’re looking for, and scatters light deep into the cloud with a smooth falloff and a nice sense of directionality and self-shadowing in the scattered light. The clouds are also lit by the surrounding atmosphere, which in this video shows up as blue in the shadows, and that environment light is also multiply-scattered through the cloud. Terragen 3 could approximate this too with GI, but the new model shows real detail and self-shadowing of the environment lighting in the areas that the sunlight doesn’t reach. The “silver lining” effect which is strongest when the clouds are back-lit is also much better than before.


Global lens effects

Terragen 4 will also features a global lens effects including lens flare and bloom that respond naturally and realistically to lighting in the scene. Lens effects operate in high dynamic range, taking into account light source and specular reflection intensity, color, occlusion, and atmospheric scattering. These effects can be independently adjusted in intensity and the lens flare “starburst” effect also has controls for softness and number of points (i.e. shape of the lens).


It looks that Planetside knows what they are doing and estimated the availably of Terragen 4 for 2Q of 2016. However, if you order Terragen 3 right now, you will get the update to Terragen 4 for free.


Terragen 4 is going to be faster, more interactive and easier to use. We’re raising the bar in terms of photorealism, while giving you new tools to create and explore your scenes more quickly and intuitively than ever before.

More information at: Terragen 4