	Voxblox: TSDF and ESDF	NeRF, iMAP, NICE-SLAM
Query a point	index a voxel: one memory read	interpolate features, run an MLP
Free space	observed free, near a surface, or unknown	whatever the network predicts, seen or not
Unseen regions	holes	filled in, plausibly or not
Appearance	one colour per voxel	new views, view-dependent colour
For a planner	ESDF distance and gradient	not stored: derive it or sample it
Loop closure	submaps, or re-integrate	none in iMAP or NICE-SLAM
Compute	CPU, at camera rate	GPU, usually below camera rate

Image: Voxblox README, ETH Zurich ASL, BSD-3-Clause

Image: NICE-SLAM repository, Apache-2.0