How to Fix Broken Physics After Changing the Timestep

Physics that breaks after a timestep change is values tuned to the old step. Re-tuning or making forces step-independent fixes it. Here is how.

How to fix it

1. Understand the dependency

Many physics values (impulse magnitudes, accumulated forces, drag) integrate differently at a different fixed step, so the same numbers produce different motion. The code did not change; the integration did.

2. Re-tune for the new step

After changing the timestep, re-tune jump forces, movement speeds, and drag so the feel matches again. Treat a timestep change as a re-tuning task, not a transparent setting.

3. Make forces step-independent

Where possible, apply forces and damping in a way that does not depend on the step size (for example, framerate-independent drag formulas), so future timestep changes do not break the feel.

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 your game 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.