What causes dynamic material instance leaks?

Creating a Dynamic Material Instance every frame or per object without reuse allocates new materials continuously, growing memory and GC pressure.

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 Dynamic Material Instance Leaks in Unreal Engine

Quick answer: Create the dynamic material instance once and cache it, set its parameters each frame instead of recreating, and reuse instances across objects where possible.

Dynamic material instance leaks are per-frame creation. Caching them fixes it. Here is how.

How to fix it

1. Create once and cache

Create the Dynamic Material Instance a single time (in BeginPlay or on spawn) and store it. Creating a new one every frame to change a parameter allocates a material each frame, leaking memory.

2. Set parameters, do not recreate

To change a material value at runtime, call SetScalarParameterValue or SetVectorParameterValue on the cached instance, rather than creating a fresh dynamic instance each time.

3. Reuse across objects

Where many objects share the same material with the same parameters, share one dynamic instance instead of one per object. Create per-object instances only when each genuinely needs different values.

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 Unreal Engine 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.