Bug: clicking a navigation arrow called app.queuePrompt() (a whole-graph
re-run). Preview nodes are V3 output nodes with no fingerprint_inputs, so
they re-execute on every queue -- which is why navigating this node reloaded
OTHER preview nodes (Preview Mesh Multi, etc.).
Fix: navigate the batch entirely client-side. The Python node now exports
EVERY mesh in the batch once and returns per-index metadata arrays
(mesh_files, vertex_counts, bounds, field_names, ...); the widget stores them
and switches meshes by posting LOAD_MESH to its OWN iframe -- no
app.queuePrompt(), so navigation never re-runs the graph or touches another
node. viewer_type is global (a function of the mode input), so switching
never needs an iframe reload either.
Also adds the requested dropdown next to the arrows: one option per mesh,
jump to any index. Arrows, dropdown, and the index widget all route through a
single client-side showIndex(); the index widget value still persists via
serialization (guarded against a re-entrant callback).
Trade-off (per the chosen approach): the batch is exported up front, so first
render is heavier for very large batches -- but navigation is then instant and
fully decoupled from the rest of the graph.
Verified: python compiles, JS parses, isolation lint still 0 errors. Needs a
runtime pass in ComfyUI (I cannot drive the node graph here).
PozzettiAndrea
923da524b9