Are you using SDFs for your road system?

That's very cool! Thinking about historic city centres, like Prague, the presence of courtyards is also really important. But what often seems to happen is that several smaller buildings will conform their fronts to the curvature of the street, being more or less rectangular themselves, but not as deep as half the block, so that they form natural courtyards between themselves and the buildings on the opposite sides of the block. So in your example, the smaller buildings might be only 2/3rds of their depth, forming courtyards in the center of the block that aren't exclusively part of any one building. I'm not really sure why it happened that way, historically, that they didn't build as deep back into the block as they could. Perhaps because the apartments were small and they could get two across a hall if the rear apartment had a window to at least some air. (Having lived in one of these rear ones in Prague for a little while, I can attest that it's not a window you want to open - the air is mostly full of pigeon feathers and excrement).

The way you have them formed, though, seems to point to an obvious algorithm that would divide building fronts into tall rectangles and stitch them together. I wonder since you already have all those nice street splines, maybe they could be applied to the building faces and rooftops as well.

>You see, the shapes of roads in real life come from an underlying essential fact: the wheel axles of a vehicle. No matter how you drive a car, the distance between the left and right wheels remains constant. You can notice this in tyre tracks in snow or sand. Two perfectly parallel paths, always the same distance apart maintaining a consistent curved shape.

Emphasis mine - that's not really true

- Cars have differentials, so the wheel speed can differ between wheels

- Steering geometry isn't parallel! The tyres turn a different amount when you turn the wheel

- Unless you're going in a straight line, cars don't go where the tyres point! Tyres 'pull' the car towards their slip angle

What you will actually see in tracks in snow or sand is non-parallel tracks, describing curves of different radii. You can also see this in racetracks, where the path more closely resembles the limits of car physics without care for passenger comfort or tyre wear. The example 'fail' image looks not dissimilar from a hairpin turn.

Their animated gif at the very end of their own tech seems very sane?

I wish they'd actually shown more/talked about it though.

> The thing is that I myself don't even know what I want to do with it.

Embrace the next challenge: Instead of roads on parabolic (Euclidean) geometry, have roads on elliptic (non-Euclidean) geometry, like the surface of a sphere. Plus, on a sphere every line is already a circular arc anyway (no matter if straight or bent, the difference is just the center, radius and normals). Thus, this system of circular arc segments really lends itself to such a space.

Little prince style micro planets with their own miniature infrastructure will always have a special place in my heart. Half a year ago I started with laying out the basics https://github.com/Lichtso/bevy_ellipsoid_billboard https://github.com/Lichtso/bevy_geodesic_grid but got distracted by fixing some engine bugs in Bevy along the way. That reminds me I have to update to the newest engine version ...

anyway you can find some of the roads on spheres stuff here: https://github.com/Lichtso/bevy_geodesic_grid/blob/main/src/... it can not only generate the extrusion mesh but also calculate how the mesh overlaps with a geodesic grid of triangular tiles on the surface.

Regarding modern roadways and viaducts that pass around medieval city cores, it's fascinating how they can be seen and still not seen. I tried to do this in Cities Skylines II for awhile, building very narrow streets in "organic" city centers with low-to-mid density, and then transitioning to a new city grid around the old center. Finally, superimposing highways and tunnels without destroying the original historical core. There were some beautiful results, but the traffic jams were astounding, even with limits on the city center roads and highway exits. This is the way cities actually grew, so to me it's much more interesting to simulate than a "perfect" city built all at once. One thing that was fun in SimCity 3000 was that certain technologies didn't become available until you had a certain population. I would almost wish that a city-builder now would allow you to take that to the extreme: Spend 200 years with horse-drawn carts before you can pave a road, and then figure out what to do with the mess. But more than anything: Oddly shaped buildings that fit into oddly shaped lots, which are not limited to hotdog stands.

Why should you use only bikes and walking? Cars/trucks have a role to play, it's just not the most efficient to move the majority of the people from one point to another. Simple examples: ambulances, firefighters, police, cranes.

> I think roads lie at the heart of every city builder. It’s the fabric on which cities are built.

To paraphrase the article, this is what urban planners have nightmares about. Roads (as in: things made for cars) aren't the fabric of a city, streets (as in: things made not only for cars, but also for pedestrians, cyclists, public transport etc.) are. See also: https://en.wikipedia.org/wiki/Stroad

Can relate the fascination with roads I use to like drawing them loads as a kid. I find Satisfactory the most satisfying for building transport systems (and building generally) your work incorporated into a mod for that would be really cool.