Are game developers and other 3d application developers (such as simulation) still willing to splash out money for a terrain engines? Or has it reached a point where such a thing will either come as part of a complete engine they've already bought a license to, or simply that terrain engines in most cases are a trivial thing to develop in-house and therefore save money. - Adam

Terrain engines in the "game" sense are relatively trivial to develop in house. I say relatively, because terrains done well in any application is not a trivial thing in my opinion. They "generally" have smaller gaming areas with very limited visibility range requirements, and only one loaded "level" to worry about at a time.

Huge outdoor areas with gigantic visibility (flight sims for instance), paging of geometry, paging of geospecific hi-res textures is NOT. Try it if you don't believe me. Therein lies the reason the vis-sim world relies on tools like Multigen Creator(with all the terrain bells and whistles) along with Vega to provide app development and visualisation of this data, Terrex (TerraPage), and Evans and Sutherlands tool(s) (whose names escapes me atm). I am sure there are more out there. These range at the bottom end of available options from $10k upward to about $50K for all the extras that make life great. And that's just for creating the geometry. The sdks for visualizing the data these generate will run you about the same on top of what you will pay for the geometry tools.

Absolutely the sim world is willing to fork out money for a good way to represent REAL WORLD data. Generating a heightmap and tiling some trivial blended textures on it is NOT the same thing, they are worlds apart.