What causes Unity animators using CPU while offscreen?

Every Animator has Culling Mode set to Always Animate, so the full skeleton and IK are evaluated each frame even for characters the camera cannot see.

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 Animator CPU Spikes Offscreen Because Culling Mode Is Set to Always Animate

Quick answer: Set the Animator Culling Mode to Cull Update Transforms or Cull Completely so offscreen characters skip pose evaluation, keeping only what gameplay needs.

A crowd of NPCs can tank frame rate even when most are offscreen because every Animator evaluates regardless of visibility. Here is how to cull them.

How to fix it

1. Switch Culling Mode

Set the Animator's Culling Mode to Cull Update Transforms so retargeting, IK, and write-back are skipped when the renderer is offscreen, leaving root motion intact.

2. Use Cull Completely when safe

For characters that do not need root motion or events while invisible, choose Cull Completely to stop evaluation entirely. Verify no gameplay reads their pose offscreen.

3. Ensure renderers report bounds correctly

Culling relies on the SkinnedMeshRenderer bounds. If bounds are wrong, characters are wrongly considered onscreen and never cull; fix the bounds or update them at runtime.

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.

Reproduce it once with full context and the fix writes itself. The hunt is the expensive part.