What causes shader banding from low precision?

Mobile GPUs default to lower (half) precision in fragment shaders, so gradients and accumulated math band where desktop full precision looks smooth.

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 Shader Banding from Low Precision on Mobile

Quick answer: Use higher precision for values that need it (gradients, accumulations), add dithering, and keep precision-sensitive math in full precision while leaving the rest half.

Mobile shader banding is half-precision math. Targeted precision and dithering fix it. Here is how.

How to fix it

1. Raise precision where needed

Mobile fragment shaders default to half (mediump or lowp) precision, which bands on gradients and accumulations. Declare full (highp) precision for the specific values that show banding, leaving the rest half for speed.

2. Add dithering

Dither the output to break up the visible steps so banding is hidden by imperceptible noise, which helps regardless of precision and is cheap.

3. Keep most math low precision

Do not make everything full precision — that costs performance on mobile. Identify the precision-sensitive calculations causing the banding and raise only those, keeping the bulk at half precision.

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.

Ship the fix, watch the signature disappear from the next build. That's how you know it's really gone.