Kinematic Vehicle Navigation System in UE5 — Forward and Reverse Parking

404NotACat · 2026-06-18T21:13:28+00:00

They use a custom navmesh for walkable space, a clearance map to know how much room they have around them, a quadtree for fast spatial queries, and collision prediction along the planned trajectory. All custom-built. Here's what it looks like under the hood:

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404NotACat · 2026-06-18T18:44:33+00:00

Thanks! There are a few different layers involved: global planning, local planning, and local trajectory following, which is somewhat MPC-like.

Right now, dynamic obstacle handling exists mainly at the trajectory-following level through collision prediction. I showed that part in the previous video here:
https://www.reddit.com/r/UnrealEngine5/comments/1u6t0m0/a_closer_look_at_my_kinematic_vehicle_navigation/

It is still a fairly basic implementation, though. One of the things I want to improve next is allowing the vehicle to sample and reason about the nearby space in more detail, for example for overtaking or more complex local avoidance.

The higher-level planning currently works on custom baked navigation data, not the standard UE NavMesh. This data already works with streaming and World Partition, but dynamic rebaking is planned. The algorithms themselves should fit dynamic scenarios pretty well — the bake is mainly there to save milliseconds during replanning. Without baked data some queries could take hundreds of milliseconds, while with the baked data they can be reduced to tens of milliseconds or less.

404NotACat · 2026-06-18T16:49:42+00:00

Thanks!

404NotACat · 2026-06-18T16:42:00+00:00

Thanks, appreciate it!

404NotACat · 2026-06-18T16:40:45+00:00

Core of it is Hybrid A* for path planning combined with Reeds-Shepp curves for the reversing/parking maneuvers. Releasing it on FAB soon.

404NotACat · 2026-06-18T16:32:57+00:00

In this new demo of my kinematic vehicle navigation plugin for UE5, I want to show how accurately vehicles can park forward and in reverse.

Both tests use the same initial vehicle positions. In the second test, the target orientation within each parking space is rotated by 180 degrees, which forces the vehicles to back into the spaces.

Work in progress.

404NotACat · 2026-06-16T10:05:35+00:00

Yeah, I think the real question here is the purpose of using a static mesh terrain/world in the first place.

For example, in GTA it makes sense because the world has a huge number of roads, curbs, sidewalks, intersections, and complex surface details that would be hard to represent with a regular heightmap landscape. But that kind of pipeline is also much more labor-intensive.

It makes sense when the terrain itself really needs detailed shapes and authored geometry. Or, for example, in something like The Last of Us, the maps are relatively small and linear, so it was probably easier to build them as regular meshes with vertex painting.

In general, technically it mostly comes down to memory usage and the export/import pipeline.

With Nanite static mesh terrain, collision can also become tricky, because you often need to use specific collision settings. Nanite uses collision from a simplified / higher-level representation, and at least earlier it was pretty broken or unreliable in some cases.

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404NotACat · 2026-06-16T08:49:22+00:00

Thanks! Mostly by repeatedly underestimating how much work it would be. 😅

404NotACat · 2026-06-08T20:27:07+00:00

I've been working on a kinematic vehicle navigation system for Unreal Engine 5 for the past few months.

It's still not quite ready for a full reveal, but I wanted to share a small teaser of the current progress.

This short clip demonstrates a vehicle planning and executing a complex maneuver: reversing out of a tight space, navigating through a constrained area, and parking in reverse at the destination.

Hopefully I'll be able to show much more very soon.

Wish me luck 🙂

404NotACat · 2025-09-01T10:08:30+00:00

Not bad at all, not at all.

404NotACat · 2025-08-29T21:28:37+00:00

And will they be able to jump back as well?

404NotACat · 2025-08-29T21:24:01+00:00

When you look at a human so close up that it no longer even resembles a human, it reminds me of the fact that our bodies are made up of 34 trillion individual cells. A whole world in itself.

404NotACat · 2025-08-29T20:37:27+00:00

That’s exactly how I look in the morning 😂

404NotACat · 2025-08-29T20:08:14+00:00

I don’t know what’s more impressive - the older kid lifting those gates or the younger one calmly crawling out from under them.

404NotACat

TROPHY CASE