FREELIGHT is an elegant and aesthetic lamp made of flexible neon, which can take any shape. You can combine lamps with each other and create unique lighting compositions and art objects from Centrsvet
https://www.centrsvet.ru/catalog/freelight_main/sweep_ceiling_brass/ 
Composition reference: https://www.pinterest.ru/pin/119978777565301912/ 
Tube diameter 25 mm
Dimensions: 1350*1350*1550 mm
Neon tubes are not editable - transferred to editable poly

For Corona render, it is recommended to install a version of at least 1.5, since the glossiness of materials is configured taking into account PBR

Those who work in V-Ray versions lower than 3.1, be careful, in the materials in the BRDF section there is Microfaset GTR ( GGX ), if your version is older than 3.1, then the BRDF field will be empty. Choose Blinn, Phong or Ward - whichever suits you best