What causes root motion on slopes and stairs?

Root motion is authored on flat ground, so on slopes and stairs the character moves the flat distance and floats above or sinks into the surface instead of following it.

How do I catch this when it only happens for some players?

Capture it automatically from the player's device with the full stack trace, the device and OS, the build, and a breadcrumb trail of what they did. That turns a vague complaint into a specific, reproducible issue you can fix without owning the hardware it happens on.

How to Fix Root Motion Drifting on Slopes and Stairs

Quick answer: Project root motion onto the ground surface, adjust vertical position to the terrain, and use foot IK so the character follows slopes and steps.

Root motion drifting on slopes is flat motion on uneven ground. Projecting it fixes it. Here is how.

How to fix it

1. Project motion onto the ground

Take the root motion's horizontal movement and project it onto the actual ground surface, so on a slope the character moves along the incline rather than the flat authored distance, which makes it float or sink.

2. Adjust vertical to the terrain

Set the character's vertical position to follow the ground height under it (a ground trace), so it stays planted on slopes and steps rather than at the flat-ground height the animation assumes.

3. Use foot IK

Apply foot IK to plant each foot on the actual surface, adapting to slope angle and step height. This hides residual mismatch and makes the character visibly conform to the terrain it walks on.

Catching the ones you can't reproduce

The hardest version of this to fix is the one you can't reproduce — it only happens on a player's hardware, OS, driver, or save state, under conditions that simply aren't present on your machine. A report that says “it crashed” or “it froze” gives you nothing to act on, so the bug survives release after release while quietly costing you players.

Automatic error capture closes that gap. Each failure arrives with its full stack trace, the device and OS, the build number, and a breadcrumb trail of what the player did right before it broke, so even a failure you have never seen becomes a specific, reproducible issue. Fold identical failures into one signature ranked by how many players each hits, and your worklist sorts itself worst-first instead of arriving as a stream of vague complaints.

This is where a tool like Bugnet earns its place. Its SDK captures every error automatically with the full stack trace plus device, OS, memory, build, and game-state context, folds duplicates into one grouped issue with an occurrence count, and ties each to the build it first appeared on — so you fix the problem that hurts the most players first and confirm it is gone when its signature disappears from the next release.

Most of the time the fix is small. Seeing the failure clearly is the part that actually costs you.