CRYENGINE (get it free here)

• CryVE: modding the cryengine2 to create a cave system http://dl.acm.org/citation.cfm?id=2554092 OR http://press.etc.cmu.edu/content/cryve-modding-cryengine2-create-cave-system but impossible to read diagrams/code online
• CryEngine Stereoscopic rendering http://docs.cryengine.com/display/SDKDOC2/Stereoscopic+Rendering (see http://docs.cryengine.com/display/SDKDOC2/Sandbox+Stereo+Usage+and+Manipulation)

UnrealEngine4 (get the UDK here)

• API Stereo rendering https://docs.unrealengine.com/latest/INT/API/Runtime/Engine/IStereoRendering/index.html
• UE4 and stereoscopic shader devhttps://www.reddit.com/r/oculus/comments/24tfyo/unreal_engine_4_stereoscopic_shader_development/
• Things to remember https://www.twentymilliseconds.com/post/unreal-engine-liveblog/
• Showcase article (2014) http://www.extremetech.com/extreme/188494-photorealism-in-unreal-engine-4-in-real-time-a-sneak-peek-at-next-gen-games-graphics
• middleVR and UE4 not yet done? See https://forums.unrealengine.com/showthread.php?4950-VR-for-projection-environments See also http://www.middlevr.com/middlevr-sdk/
• MiddleVR for Unreal in a Cave demo video https://www.youtube.com/watch?v=REfLUtqELjU
• remember CAVEUDK? http://hci.uni-wuerzburg.de/projects/caveudk.html

BLENDER (get it free here)

• What can the Blender Game Engine do?
  https://www.blender.org/manual/game_engine/introduction.html
• Examples http://www.tutorialsforblender3d.com/Demos/Demos.html and http://www.indiedb.com/engines/blender-game-engine/downloadsOR https://apricot.blender.org/download
• Using Blender for a Dome: http://paulbourke.net/dome/BlenderiDome/ e.g. http://paulbourke.net/papers/blender10/
• How to: Blender to 360 http://blender.stackexchange.com/questions/30924/how-to-make-360-renders-for-virtual-reality-devices-ie-oculus-etc-using-blen
• Blender to Oculus Rift DK2 http://blender.today/p/addons/hgbbbc/blender-vr-viewport-with-oculus-rift-dk2
• Blender to JanusVR http://www.thevrexperts.com/fire-export-blender-scenes-straight-to-virtual-reality/
• BlenderCave (has it been updated since 2011?: https://www.blender.org/forum/viewtopic.php?t=21330) See http://www.gmrv.es/Publications/2011/GBEO11/
• Blender and WebGL http://www.webgl-game-engines.com/blend4web.html
• Or via Three.js exporter https://speakerdeck.com/yomotsu/webgl-plus-3d-models-by-using-three-dot-js-blender-exporter

UNITY (get it free here)

• Unity Editor on Surround Wall Projection https://www.youtube.com/watch?v=Gb9ayYGM-4c from 2011

nb Image above Unreal Tournament from downloadable model at http://publicvr.org/