I use both Vue and Terragen. In Vue I have an Aerial perspective number I can increase to give the illusion of distance. How do I do that in Terragen?
I think TG simple doing this automatically. Otherwise you can increase the haze of the atmo if you want a stronger effect. Otherwise try the Distance Shader.
Hope we talking the same thing here...hehe :D
"Aerial Perspective" is an artistic term for the appearance of distance due to the affect of the atmosphere on light as it travels longer and longer distances. Terragen simulates this realistically with real-world distances (measured in meters). So the default setup should give you a realistic correlation between the size of your terrain and the apparent atmosphere density and light scattering. But of course there are a large variety of atmospheric conditions.
To increase the effect you can indeed just increase Haze. You may also at the same time want to increase Bluesky Density and Bluesky Additive, not as much as Haze probably, but this will help keep a balanced, realistic look to your more dense atmosphere. Note that the Bluesky Density affects the Bluesky Additive, but not the other way around. If you want a more blue appearing haze, increase the Additive without increasing the Density further. This is a look many people associate with greater distance, for example think of the Great Smoky Mountains in the US, with that characteristic blue haze and distant mountain silhouettes.
I recommend you use the RTP (Ray Traced Preview) when adjusting atmosphere parameters as the response time is much faster than the regular 3D Preview and it will help you quickly see the effect of these setting changes.