How to explore
Rendering: rotate and resize the front Gaussian, lower its opacity, then select a ray in the image. Compare each intersection's range, opacity, and front-to-back weight. Switch between accumulated range, opacity-normalised expected range, and opacity.
Registration: run the room-corner case, then switch to a corridor. The geometric residual can become very small while motion along the corridor remains unobservable. Increase the synthetic noise along surface normals to see an actual residual floor.
Scope: this is an explanatory simulation. It uses three planar 3D Gaussians and per-ray sorting, not the paper's GPU tile rasteriser. Its registration lab implements only the geometric point-to-line SE(2) analogue. Splat-LOAM uses SE(3), rendered-keyframe geometry, and a joint geometric plus range-image warping objective; Gaussian map optimisation is a separate operation. The repository's optional median-depth mixture is omitted.
Paper: §§3.2, 3.3.3 · Reference implementation