It's good to have land
Landscape rendering is the display of the features of an area of land using polygons. That includes the terrain, water bodies, vegetation, sky and lightning. The example page lists a number of games and how i think they did the landscape.
Geometry :The triangles of the terrain. A common way to create this is to use a heightmap.
Material : The textures and shaders that are used on the terrain.
Water: Pond, rivers, lakes or the sea.
Decoration: Undergrowth, grass, plants, stones and trees.
Sky: Clouds, sun, starts and the moon.
Generation
Rendering the Great Outdoors: Fast Occlusion Culling for Outdoor Environments - 2002
Reference
The Terrain of Halo Wars - 2017
Dissecting “Tiny Clouds - 2017
Fast Terrain Rendering with Continuous Detail on a Modern GPU - 2014
PhysX Dynamic Heightfield Modifications - 2014
Landscape Creation and Rendering in REDengine 3 - 2014
Rendering Massive Virtual Worlds SIGGRAPH 2013 - 2013
Virtual Texture Terrain - 2013
Project Frontier - 2011
http://www.gdcvault.com/play/1277/HALO-WARS-The-Terrain-of - 2009
Terrain Project - 2006
Procedural Planets Part 1 - Structure - 2004
Real-time rendering of large terrains using algorithms for continuous level of detail - 2002
Tutorial 13: Terrain Detail Mapping
A Scalable and Production Ready Sky and Atmosphere Rendering Technique
Interactive Wind and Vegetation in 'God of War' (2GB pptx!)
Rendering volumetric clouds using signed distance fields
[video] Animal Crossing, wobbly leaves, pivot caching.
Terrain and Mesh Blending in Unity
Positional Effects (Scattered Objects Moving Back / Growing Flowers)
Multi-resolution Ocean Rendering in Crest Ocean System [280 MB pptx]
Terrain and Mesh Blending in Unity
Wind Simulation in God of War - 2019
A Heightfield on an Isometric Grid - 2005
Advanced Graphics Tutorial: Wakes, Explosions and Lighting: Interactive Water Simulation in Atlas - 2021
Painting a Landscape using Mathematics
https://www.youtube.com/watch?v=BFld4EBO2RE