Why does Light Probe Group bake fail to converge?

Probes outside the lit volume sample dark; with low Indirect Samples the result is noisy and never converges. Place probes inside the lit area, raise Indirect Samples in Lighting Settings to 1024+.

Tetrahedral mesh interpolates between probes. Place denser probes around lighting transitions (door thresholds, indoor/outdoor).

Adaptive Probe Volumes alternative?

HDRP/URP Forward+: APV auto-places probes. Less manual work; Light Probe Groups are the legacy explicit-placement method.

Fix: Light Probe Group Bake Won't Converge

Quick answer: Place probes inside lit volume, not outside walls. Lighting Settings → Indirect Samples 1024+. Use Adaptive Probe Volumes for automation.

Bake runs forever. Or finishes with noisy probes. Probes were placed too sparse and outside lit areas.

The Fix

Lighting Settings:
  Indirect Samples:    1024     // up from default 256
  Bounces:             2
  Indirect Resolution: 2        // texels per unit
  Lightmap Padding:    2

Light Probe Group:
  Probes inside lit volumes
  Density higher near transitions

// Or use Adaptive Probe Volumes (URP / HDRP)

More samples = lower noise. Probes inside lit areas converge correctly.

Verifying

Bake completes in reasonable time. Probes show smooth gradient. Without samples bump: noisy spots, slow convergence.

“Inside volume. Many samples. Bake clean.”

Related Issues

For occlusion bake, see occlusion. For HDRP fog, see HDRP fog.

Inside volume. Samples up.