Why does TAA ghost behind fast-moving objects?

TAA accumulates samples temporally; fast motion exceeds reprojection's tolerance, leaving trails. Use Responsive AA on the material (special pixel shader), or switch to TSR which has better motion handling.

Temporal Super Resolution. UE5's upscaler with built-in better motion handling than TAA. Project Settings → Anti-Aliasing Method = TSR. Costs more but cleaner.

r.TAA.HistoryRejection / r.TAA.LumaContrastFactor for legacy TAA. r.TSR.History.SampleCount for TSR. Profile to find sweet spot.

Fix: TAA Ghosts On Fast-Moving Objects

Quick answer: Switch to TSR (UE5). Or enable Responsive AA on the affected material; ghosts visibly reduce.

Fast bullet trail leaves visible ghost behind. TAA can't reject the moving sample; smear results.

The Fix

Project Settings → Rendering → Anti-Aliasing:
  Anti-Aliasing Method:        TSR     // UE5

// Or per-material Responsive AA
Material:
  Lit Translucent — check Responsive AA in details
  (works for translucents and emissives)

// Console
r.TSR.History.SampleCount  8      // up from default 4

TSR is the modern recommendation. Responsive AA flag is a per-material opt-out from history accumulation; reduces ghost at cost of slight aliasing.

Verifying

Fast-moving object: ghost gone. Static scene: AA quality preserved.

“TSR or Responsive AA. No more smear.”

Related Issues

For mobile shader precision, see mobile precision. For PostProcess alpha, see PP alpha.

TSR. Or Responsive AA. Crisp.