There’s a lot to try to diagnose here. First of all…agreed with all of @DaveR 's comments re: purging, using groups and tags, and making sure there are no reversed faces.
Next, not sure why - but I’m getting a lot of errors. The model is ‘buggy’…perhaps it’s trying to reference material data from the OP’s hard drive. I’d recommend a thorough cleaning of the model. Check out Thom Thom’s CleanUp Extension.
I ended up copy the model geometry and pasting into new fresh clean file -which helped some.
Next, re: the original question about lighting…I deleted all the existing lights and reset V-Ray’s render settings to default so I can start from scratch. When dealing with lighting, I recommend using the ‘Material Override’ setting so that you’re looking at just light and nothing else.
For glass materials, since you want light to come through it, It helps to uncheck ‘can be overridden’ in the materials property settings.
Moving on…the room is naturally dark because the only windows are on the east and west sides…which means you need to adjust your shadow to reflect either earlier in the morning or late afternoon so the sun can ‘come into’ the room.
Here is default lighting with some light coming from the opening next to the dining room table.
I’m a bit lazy so when I want to brighten a view up, I add an ‘Exposure’ to the corrections panel in the VFB/Frame Buffer. Make sure to also bring the ‘Highlight burn’ down as well.
Next. Try working with Sphere lights first. To me, they are the most versatile and forgiving when just starting out. Here I’ve added one sphere light inside of the hanging fixture above the island. I added it INSIDE the light component so it showed up in all the others. That way I only need to edit one light and it updates them all.
Lastly, you can also see what it looks like when you adjust the sun position to come in from the other side. I say this as you want to work with your natural or environmental light first as if that’s done well, you won’t need much more in terms of artificial lights.
From here, I would just add a few lights at a time, making sure that if they are inside of a lamp, that you uncheck ‘can be overridden’ for that lamps material so that you can see the light come through. Be patient. Good lighting is an art and I’m no expert…I just know enough that it takes a lot pr practice and in some case, experimentation to get the results that will look the best.
Hope this helps some.
