Using OS Terrain50 with VectorMap District's water and woodland polygons I used Safe's FME Desktop to generate a landscape inspired by Owen Powell's work.
FME lets you export the triangular faces of the TIN as polygons.
Using the FME Data Inspector to view the surface in 3D.
Rendered in QthreeJS in QGIS - the Angus Glens
The Spittal of Glenshee - QthreeJS
The rather untidy workbench processing the data.