Okay i made a huge mistake building a huge scale island for off-roading. Thankfully i can reset back with minimal loss since most track object is recoverable in modular. The vast track size to roam sounds a good idea but the limitation on the amount of track object to populate the island is limited and may leave voids between distance which makes the environment looks barren empty hider the realism looks on the surroundings. Also i've lowered the ground altitude to more realistic climbing angle and also narrowed the driving trails to give more challenging off-road driving experience. The smaller island provide narrower turning around the corners and steep angle driving plus avoid 'LOD' distance object to spoil the view. It took me 1 hours to drive around the track due to challenging narrow and twisty trails fits for rock crawling style adventure.
