JanusVR automatically generates radiance and irradiance maps for global lighting based on the skybox imagery. However, if the user wishes to define their own there are simple markup tags to do so. Radience and Irradience maps must be defined as AssetImages whose source files are .dds format.
Currently this feature only works in JanusVR native while janusweb must use env_map.
http://janusvr.com/docs/build/roomtag/index.html#Room
cubemap_radiance_id - (default "") Defines the radiance map to be used.
cubemap_irradiance_id - (default "") Defines the irradiance map to be used.