tvbo brain

The ASCII spec-to-cortex portrait: a model spec coming apart and reassembling as a cortical surface drawn from its own characters.

Reference·Verbs

tvbo brain draws a model spec dissolving into a cortical surface built out of the spec’s own characters: the terminal form of bsplot’s Spec to cortex portrait.

A bare tvbo shows the same surface at banner scale — the name on the left edge, a cortex on the right, and the command list underneath. Three details make that banner work:

• the mark is the wordmark spelled out in block characters, in the TVB-O brand blue. The real artwork is a raster logo; at a dozen character cells its letterforms turn to mush, so the banner spells the name instead. The artwork path is still there for whenever a mark that survives the size turns up: hero(mark="logo") draws it, and tvbo brain --save-logo rebuilds its asset.
• the cortex is shaded through the coarse " .:-=+*#%@" ramp, not a letters ramp: at a dozen rows tonal contrast is what makes it read as a brain, and letterforms only add noise. The lighting is re-stretched after resampling, because box-averaging a 156×60 grid down to 30 columns otherwise flattens every cell toward the mean.
• the cortex keeps its own proportions, so the shared row count sets its width; the tallest band that still fits both columns between the two edges wins, and the name is centred in it. Below the width where both fit, the cortex gives way and the name stands alone.

Synopsis

tvbo brain [SPEC] [--animate] [--bg dark|light] [--width N] [--plain] [--no-flow]
                  [--hemi lh|rh|both] [--view lateral|medial|top|...]
                  [--render] [--save-asset PATH]

SPEC is any path, CURIE, or database name whose text supplies the glyphs — tvbo brain dynamics:Generic2dOscillator, tvbo brain ./my_study.yaml. It defaults to the curated Jansen1995 model.

What you are looking at

Three things happen left to right:

• the spec: the YAML as written, every glyph a source with a real position;
• the flow: a sample of those letters caught mid-flight, on an arc toward the cortex;
• the cortex: one fsaverage pial surface. Each cell’s glyph comes from an ink ramp built out of the spec’s own character set, so the 3-D form reads through glyph density even with colour off, and the colour is the surface’s binarised curvature (gyri light, sulci dark) shaded by the lighting. A C lands from a C in the text.

--animate plays the dissolve: every glyph rests on its spec position until its departure beat, then flies to its cell, departures sweeping the spec in reading order.

Options

Option	Meaning
--animate, -a	Play the dissolve in place instead of printing the still frame.
--bg dark\|light	Theme the output for the background it is viewed on. On a light background the ink ramp flips, so the sulci carry the heaviest ink.
--width, -w	Portrait width in characters. Defaults to the terminal; the cortex keeps its own aspect and the spec column is dropped when the terminal is too narrow.
--plain	Plain characters, no ANSI escapes — for a README, a log, or a pipe. Colour is dropped automatically when stdout is not a terminal or NO_COLOR is set.
--no-flow	Drop the letters caught mid-flight.
--hemi, --view	Hemisphere and view to render live; only meaningful with --render.
--render	Re-render the surface geometry with bsplot instead of using the shipped one.
--save-asset PATH	Write that render as a reusable asset (implies --render).
--save-logo PATH	Re-render the TVB-O logo from the project artwork into an asset and exit.

Why it is instant

The logo ships as tvbo/data/media/logo_ascii.txt (an alpha block, a palette-indexed colour block, and the palette), because rebuilding it needs an SVG rasteriser (rsvg-convert or inkscape), which is exactly why it ships. The surface geometry ships precomputed as tvbo/data/media/cortex_ascii.txt: a text grid holding, per character cell, the shading intensity and the binarised curvature, cropped to the cortex bounding box, plus the measured ink ordering of printable ASCII. Printing the portrait is a file read and some arithmetic: no bsplot import, no template download, no network.

--render is the escape hatch when you want another view, and --save-asset regenerates the shipped grid:

tvbo brain --render --view medial              # a live render, this once
tvbo brain --render --hemi rh --view lateral \
           --save-asset tvbo/data/media/cortex_ascii.txt

That path needs bsplot plus the fsaverage template data (fetched through templateflow), which is exactly why the result is shipped rather than recomputed on every invocation.

Examples

tvbo                                   # the hero banner + the command list
tvbo brain                             # the portrait, sized to your terminal
tvbo brain --animate                   # watch the spec come apart
tvbo brain dynamics:JansenRit --bg light
tvbo brain ./study.yaml --plain -w 100 > portrait.txt