The LightWave Assets / Plugins database maintains a list of free and commercial third-party plugins available for LightWave.
Digital Elevation Map (DEM) importer
Render very large images without running low on memory
Exports LightWave animation (camera, sun, water) to a Terragen file
Create a mesh from a DEM file
Loads a variety of different DEMs as gray scale images
Builds an optimized landscape from an image or procedural