Six ways the 3D viewer can do the job of that sagittal figure

The 2D graphic was not a tractography dump. It was a labelled sagittal of six functional systems, with nuclei as nodes and margin cards that say what each system is for. Show-all fibres broke that. These six variants keep the figure’s job and use 3D, volumes, named tracts, and hover only where they add something the still cannot.

Variant A is now the live viewer’s home screen. The others are still proposals. Steal pieces. Mix them.

What that figure was doing

One glance at six systems, not 87 filesAffect, motor planning, nociceptive processing, TPJ, value, descending modulation
Named nodes on a quiet brainPFC, ACC, insula, SMA, M1, S1, S2, TPJ, thalamus, striatum, amygdala, hippocampus, PAG, LC. RVM drawn, absent here.
Colour means functionRed sensory/motor, purple affect, cyan value, green descending
Margin cards, not labels on the tissueWhy the region matters for pain, including the chronic-pain line
Implied cables, not a hairballThe still never showed every streamline. It showed that systems talk.
A right sagittal as the default teaching viewThe 3D app already has this camera. The figure was the density target, not a new camera problem.

Variant A

Six lamps, one brain

Default scene is the figure: quiet cortex, six system colours on the named nodes, no tracts. Click a system card. Only that system’s nodes stay lit, and only the fibres that join those nodes appear. 3D is for inspecting the volume. The card is for the story.

Click a system. Tracts in this toy are a few champion polylines, not the 160-line files.

Shows

The 2D grouping as the home screen. Tracts as evidence for one system at a time.

Hides

Every fibre until a system is chosen. Cross-system cables until you add a second lamp.

Variant B

Keep the figure as the table of contents

Left: the sagittal schematic, always visible. Right: the live 3D stage. Click a node on the left. The right camera holds the teaching sagittal and isolates that volume plus its linking fibres. You never lose the map while you inspect the mesh.

Click a labelled node on the left. The right panel is a stand-in for the existing WebGL canvas.

Shows

The 2D figure as navigation. 3D as a microscope, not as the only map.

Hides

The need to remember where PFC sat while you orbit. Orbit can be a secondary gesture, not the way you find anatomy.

Variant C

A named graph, with tracts as footnotes

Draw nodes at structure centroids and one edge per named HCP1065 bundle that meets both ends. The hairball becomes a circuit diagram in the same sagittal. Hover a node: incident edges light, and one representative streamline per bundle ghosts in as the evidence.

Hover Th, PFC, or Ins. Edges are named files (UF, TR_A, TR_S), not 7,000 lines.

Shows

The connections the 2D figure implied, with atlas names attached. Honesty: RVM has no edge.

Hides

Streamline density until you ask for the footnote fibre. Pass-by can be marked on the edge, not exploded in the volume.

Variant D

Unstack the still into three plates

The painted figure is three stories on one brain. Split them: nociceptive processing, affect and value, descending modulation. Each plate shows only those nodes and a handful of linking fibres. Same camera. Same honesty notes. Like figure panels in a paper, not one overloaded sagittal.

The motor strip can sit with nociceptive processing, as in the original red group, or move to its own plate later.

Shows

One functional story at a time. Chronic-pain lines stay on the plate that owns them.

Hides

Affect cables while you teach thalamic radiation. Descending nuclei while you teach S1.

Variant E

One hop from here

Click a structure. The scene keeps that node and its immediate neighbours. Only fibres that meet the clicked node and another pain-map node are drawn, with sparks from the click. A second click locks a pair. This is Show all turned into a query, which is what the 2D figure did when your eye went from Th to S1.

Click Th, then S1, then PFC. The neighbourhood is 1-hop in the page’s structure list, not a new connectome.

Shows

Local circuitry without the 7,568-line union. Sparks earn their keep because the set is small.

Hides

Far systems until you walk to them. CST to M1 does not appear when you are asking about amygdala.

Variant F

Play the still

The 2D figure is a photograph of a process. Play it as four beats, using only named stand-ins the atlas actually has: thalamus and S1 as the body-map stand-in (not STT), then affect nodes, then value nodes, then PAG and LC. Each beat lights a system and runs sparks along the fibres that join the newly lit nodes. RVM is announced as missing at the last beat.

Beat 0. Quiet sagittal. Press Play.

Shows

Order of a teaching story. Arrival times can stay honest: same shown speed, longer fibres later.

Hides

The lie that HCP1065 contains a spinothalamic tract. Beat 1 must say “thalamic radiation stand-in” out loud.

Steal list

What to mix

Most of these can stack. A likely mix: A as the home screen, E as the click language, C as an optional overlay, F as a “play the figure” button, B if the schematic must stay on screen while you orbit.

2D job	A lamps	B toc	C graph	D plates	E hop	F play
See six systems at a glance	yes	yes		yes		yes
Named nodes, quiet brain	yes	yes	yes	yes	yes	yes
Function colour	yes	yes		yes		yes
Margin story cards	yes	yes		yes		yes
Cables without a hairball	yes		yes	yes	yes	yes
Use 3D volumes		yes			yes
Use named tract files	yes		yes		yes	yes
Use sparks / time					yes	yes
States the atlas gap (RVM, STT)			yes			yes