Implicit Adam Updates & Dead Primitives in 3DGS

Investigating how standard Adam's implicit parameter updates accelerate dead primitive formation in 3D Gaussian Splatting compared to Sparse Adam.

59.95%
Adam Dead Primitives
41.50%
Sparse Adam Dead Primitives
0.9005
Decay Ratio per Invisible Step
6.61
Half-life (steps)
386.3
Mean Excess Dead (10 seeds)

Main Comparison

Dead Primitives: Adam vs Sparse Adam

Opacity Statistics

Sensitivity Analysis

Learning Rate Sensitivity

Gradient Bias Sweep

Multi-Seed Robustness (10 seeds)

Feedback Loop: Drift & Visibility by Quartile

Detailed Results

Main Comparison (2,000 primitives, 3,000 steps)

MetricAdamSparse Adam
Final Dead Count1,199830
Dead Percentage59.95%41.50%
Peak Dead Count1,202830
Mean Final Opacity0.02050.0260
Median Final Opacity0.00250.0073
Total Implicit Drift36,382.80.0
Mean Drift/Primitive18.190.0

Opacity-Visibility Feedback Loop (Adam)

QuartileOpacity RangeMean DriftMean VisibilityDead Count
Q1 (lowest)[0.0, 0.0005)18.84493.06500
Q2[0.0005, 0.0025)18.39514.43500
Q3[0.0025, 0.014)17.88552.92199
Q4 (highest)[0.014, 0.788]17.66623.340

Learning Rate Sensitivity

Learning RateAdam DeadSparse DeadDifference
0.01000
0.02761561
0.051,199830369
0.101,7451,615130
0.151,8731,81657
0.201,9181,88731