so, we are looking at a city here: 3D Models | Over a Million Models for Download | TurboSquid
But i’m not really sure that it is fit for real-time rendering, can anyone guide me to an article, with a scale so i can make some how a correct estimation of the models i am picking for our projects…
this one as 2.5 Million poly, i could do some kind of draw on command, but for a city like this it is hard to optimize much.
Thanks.
I can’t really guide you to an article but I can tell you that not even people with the latest graphics cards will be able to properly view your scene if it has 2.5 million polys with buildings most of which are going to be visible most of the time. You’d need some serious portal-culling to optimize such a scene (and portal culling isn’t implemented in Unity as a ready-to-use system). I hope someone else can offer you more useful advice but it would take a big team effort to make that city realtime-renderable. If you were to make it smaller, add in shadow-casting optimizations, add some fog to hide objects in the far distance, then it could potentially work.
Best of luck.
It all depends on the target you aim for.
Surely a 2.5 million polys scene is hard to view for most of machines today.
I tested my machine speed with Unity a couple of days ago, and with 1.200.000 polys it was running at 70 fps.
So I can think you could run that scene on most of actual machines at around 20-30 fps.
But this is theory.
You must convert that scene to the Unity format.
And I don’t know how many shader that scene has.
And number of visible shaders is one of the essential keys to framerate.
I’ve spent a fair bit of time converting high poly models (either engineering models or those built for frame by frame rendering) to low poly / medium res textures for Unity. I’ve also imported some fairly high poly models into Unity. Remember you have a 32,000 poly per object limit you cannot exceed so you would, at the very least, have to make sure your model’s objects are no larger than that otherwise you’ll get an error message. I would think the work involved to make this city model to work efficiently in Unity (or any 3D game engine) would take many man-hours (likely many man-weeks).
You might want to consider a model that is intended for realtime use, like this one: http://www.turbosquid.com/FullPreview/Index.cfm?id=313623
65,536 vertex limit actually. 
–Eric
true.
but i need the city to be as HD/HQ as possible.
and that city would not do for a fps on that level.
Oops, right. Thanks for that Eric.
Gotcha. You really won’t know how much work would be involved to clean up and convert this model until you buy it and open it up in your 3D modeling app. You might be luck and the modeling, UV’s, materials and textures might be done in a manner similar enough to what you want so that all you’d need to do is a simple clean up and cut the city into 65K “pieces”. So far I’ve never been that lucky, and the models we get basically need to be completely re-modeled in order to work properly.