How large can a nanite mesh be (physical BB dimensions)?

I’m working on an urban scene and I wold like to create a network of roads. Landscape spline meshes are not working out since they don’t have the flexibility needed since roads tend to be very diverse even for short runs. So I want to create nanite roads in sections and join them together in the map. The question is how large can a nanite mesh be in physical size. I’m thinking about doing road sections up to 300m in length. This would make for a bounding box of around 300x60x20 meters per section. Is this going to work?

Hi Whammy,

From my own experimentations that can certainly work, but I have come against some limitations. In the past I have created roads with millions of polygons each and multiple kilometers long, all unique meshes. After about 10 of these or so the Nanite system seemed to breakdown (streaming settings of multiple configurations made no difference).

However, 300m isn’t a huge distance and if you can use them multiple times that will save significant resources. For example, instead of having two 300m stretches of road just for different pavements, separate the road from the pavement and use the road mesh twice and two different pavement meshes instead.

Hope that helps!

I’ve discovered that nanite and roads don’t mix very well. In my case, I have some roads with curbs, sidewalks and crowned pavement. The issue I am running into is that I’m using ‘complex as simple’ collision which is causing issues with nanite. It seems nanite greatly simplifies the collision mesh to the point that the player’s feet disappear into the sidewalk. The poly count is pretty conservative. So I’ve gone back to using standard meshes.

Interesting. I’m also using Nanite meshes for collision, but the difference for me is that I’m using separate invisible nanite meshes for it. Running separate meshes for collision may work for you too.

I’ve found performance with conventional and nanite meshes mixed together goes down a bit, that’s why I’ve made every static mesh I have into a Nanite version.

It’s also worth noting that nanite doesn’t handle layered meshes well too, so that’s something to avoid: Nanite and Closely Stacked Surfaces