Thanks. I knew that but I forgot to put it in there.

If you are using an HDRI as a dome light, you only need to disable the GI and BG in your Environment. You should exposure in PC. I dont know why you would ever disable this.

Thanks!

You can also consider Simlab Composer! An easy one! And it works for quasi any formats files!

I would recommend exporting that landscape as a proxy if you do want it in the scene. 4mil faces isn't an issue with proxies. It's an issue when they are just faces in SketchUp though, because that means we have to crawl through 4 million entity objects in SketchUp, examine what material is applied to each entity, build the mesh, etc... could take ages. If it's a proxy, the geometry is already in a format V-Ray understands, and it can work with it very quickly and with little overhead.