If you are a large visualization project, you probably aren't coding a game engine, so you'd use whatever the visualizer uses. They typically treat code as data too.<p>1. <a href="https://github.com/Allar/ue5-style-guide">https://github.com/Allar/ue5-style-guide</a> (Unreal Engine game engines organization)<p>2. <a href="https://www.usgs.gov/faqs/what-geographic-information-system-gis" rel="nofollow noreferrer">https://www.usgs.gov/faqs/what-geographic-information-system...</a> (Map systems)<p>3. regular databases (postgresql / oracle)<p>4. sims smart objects
(Oops misread. you said source code. Perforce.)<p>Most project I know use perforce to store a few terabytes of art data and the game project.<p>Another project used Google Drive for the same purpose.<p>Some groups built entire platforms <a href="https://sketchfab.com" rel="nofollow noreferrer">https://sketchfab.com</a> (Epic Games) or <a href="https://github.com/nuxeo-archives/nuxeo-platform-3d">https://github.com/nuxeo-archives/nuxeo-platform-3d</a> (Electronic Arts)<p>Cesium3D uses 3d tiles and storing the data tables inside of the gltf 3d asset.
OpenUSD is probably the largest example of code visualization libraries. <a href="https://openusd.org/release/api/arch_page_front.html" rel="nofollow noreferrer">https://openusd.org/release/api/arch_page_front.html</a><p>You can look at the shared source game engines. <a href="https://github.com/epicGames/unrealEngine/">https://github.com/epicGames/unrealEngine/</a> (need to sign license)