UI audit fixes: safe split defaults, spacing-table ghosts, rotation marker, split options in export

- Split Starting Nozzle / Starting Valve default to the next numbers past
everything in use, refresh on every table change, and re-bump after
each split - a default split can no longer land pieces on another
shape's nozzle (silently forming a multi-material assembly) or reuse
its valves.
- The ghost-row pass now covers the Advanced Grid Spacing table, and the
rule is stronger for both tables: when any live (button-wrapped) rows
exist, every outer-copy row is a render leftover - which also removes
stale rows whose pair/shape no longer exists (e.g. the self-paired
"Nozzle 2 -> Nozzle 2" leftover).
- Rotated shapes are marked at the START of the STL cell ("↻90° name").
Display-only: reading the table back strips the marker, and the group
summaries ignore it.
- Save/Load Settings now includes the Multi-Nozzle Split geometry
options (columns, rows, both interlocks, row-overlap direction,
overlap depth). Starting nozzle/valve stay auto-computed.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

README.md

@@ -51,11 +51,11 @@ Then open the local Gradio URL in your browser, upload STL files or load the bun
 - Port groups are marked too: shapes sharing a Port get a matching underline on their Pressure and Port cells and a summary line ("Port 1: A + B share one pressure regulator (25 psi)") — one regulator per serial port is why their pressures stay in sync
 - Automatically unions the sliced shapes into a combined reference layer set whenever shapes are sliced
 - Shows a sliced-layer preview in the Selected Shape Preview accordion (layer slider through the shape's polygon outlines, drawn in its print color; assembly parts sharing the nozzle are drawn together so multi-material slicing can be checked before generating G-code)
-- **Rotate a shape to print in any direction**: the Selected Shape Preview accordion has a Rotate (°) input that spins the selected shape on the bed (about Z, around its center) before slicing — the configured table dimensions follow the rotation (a spun 20 × 8 shape becomes 8 × 20, keeping any custom scaling), and the 3D/layer previews show the rotated shape. **Rotate All Shapes** applies the same angle to every uploaded shape at once (each carrying its own dimensions through the turn; split pieces are skipped). Assembly parts sharing a nozzle rotate about the group's combined center, so equal rotations turn the whole assembly as one unit. The rotation exports/imports with the other settings. (The engine also supports X/Y tilts, not yet exposed in the UI)
+- **Rotate a shape to print in any direction**: the Selected Shape Preview accordion has a Rotate (°) input that spins the selected shape on the bed (about Z, around its center) before slicing — the configured table dimensions follow the rotation (a spun 20 × 8 shape becomes 8 × 20, keeping any custom scaling), and the 3D/layer previews show the rotated shape, and the table marks rotated shapes at the start of the STL column ("↻90° name"). **Rotate All Shapes** applies the same angle to every uploaded shape at once (each carrying its own dimensions through the turn; split pieces are skipped). Assembly parts sharing a nozzle rotate about the group's combined center, so equal rotations turn the whole assembly as one unit. The rotation exports/imports with the other settings. (The engine also supports X/Y tilts, not yet exposed in the UI)
 - Bundled sample sets include a **Multi-Material Demo** (checkerboard cube, wrapped egg, space helmet — two STLs each) that loads with the parts of each model already grouped onto shared nozzles, forming three assemblies in one click
-- **Save / Load Settings**: exports every table setting plus the generation options as a small JSON keyed by STL filename; re-upload the same STLs later (or after a Space restart) and import to restore the whole setup — files in the export that aren't loaded yet are listed so they can be added. Split pieces are derived geometry and don't round-trip
+- **Save / Load Settings**: exports every table setting plus the generation options (Multi-Nozzle Split geometry options included) as a small JSON keyed by STL filename; re-upload the same STLs later (or after a Space restart) and import to restore the whole setup — files in the export that aren't loaded yet are listed so they can be added. Split pieces are derived geometry and don't round-trip
 - Generate G-Code reports live progress (slicing, reference building, then shape-by-shape generation)
-- Splits one sliced shape's geometry into an editable row/column grid for multi-nozzle printing of one large shape
+- Splits one sliced shape's geometry into an editable row/column grid for multi-nozzle printing of one large shape. The Starting Nozzle / Starting Valve defaults always sit past every number in use (and re-bump after each split), so a default split never lands pieces on another shape's nozzle or valve
 - Converts sliced layers into G-code files with pressure, valve, nozzle, port, and infill % settings per shape from the Shape Settings table
 - **Pressure is a port property** (one pressure regulator per serial port): shapes sharing a Port always share one pressure — editing one shape's pressure updates every shape on that port, moving a shape onto a port adopts that port's pressure, and newly added shapes join at their port's existing pressure
 - **Infill %** per shape skips dispensing on evenly-distributed raster lines (rings for the circle spiral) — at 50% every other line prints. Parallel shapes with different infill still share one print path, and lines that **no** shape dispenses on are dropped from the motion entirely instead of being swept valve-off (every shape at 50% roughly halves the print path; with mixed infills a line survives if any shape prints it). The rectangular spiral keeps its full continuous walk; circle-spiral perimeter walls always stay

app.py

@@ -634,7 +634,23 @@ APP_HEAD = """
         return isNaN(value) ? null : Math.round(value);
     }
     function cellName(td) {
-        return ((td && td.textContent) || '').replace(/\\u22ee/g, '').trim();
+        // Strip the cell-menu glyph and the display-only leading rotation
+        // marker ("↻90° name").
+        return ((td && td.textContent) || '').replace(/\\u22ee/g, '').trim().replace(/^\\u21bb\\S*\\s*/, '');
+    }
+    function hideStaleCopies(containerId) {
+        // Gradio renders each dataframe TWICE (a button-wrapped live copy
+        // plus an outer copy that can hold stale leftover rows). When ANY
+        // live rows exist, every outer row is a render leftover — hide it.
+        var container = document.getElementById(containerId);
+        if (!container) return;
+        var rows = Array.prototype.slice.call(container.querySelectorAll('table tbody tr'));
+        var anyLive = rows.some(function (tr) { return tr.querySelector('td') && tr.closest('button'); });
+        rows.forEach(function (tr) {
+            if (!tr.querySelector('td')) return;
+            var live = !!tr.closest('button');
+            tr.style.display = (anyLive && !live) ? 'none' : '';
+        });
     }
     function refresh() {
         var container = document.getElementById('shape-settings-table');
@@ -685,16 +701,19 @@ APP_HEAD = """
             }
             entry.copies.push({tr: tr, tds: tds, live: fromLive});
         });
-        // Ghost pass: when a Shape number has a LIVE row, any stale copy of
-        // it in the outer table is a render leftover — hide it; every other
-        // recognized row is explicitly shown (it may have been a ghost in a
-        // previous render). Unrecognized rows keep their current state.
+        // Ghost pass: when the table has ANY live (button-wrapped) rows,
+        // every outer copy is a render leftover — including stale rows
+        // whose Shape number no longer exists. Only when NO live rows
+        // rendered at all does the outer table stand on its own.
+        var anyLive = entries.some(function (entry) { return entry.fromLive; });
         entries.forEach(function (entry) {
             entry.copies.forEach(function (copy) {
-                var hide = entry.fromLive && !copy.live;
-                copy.tr.style.display = hide ? 'none' : '';
+                copy.tr.style.display = (anyLive && !copy.live) ? 'none' : '';
             });
         });
+        // The Advanced Grid Spacing table has the same double render (and
+        // showed stale self-paired rows); same rule, no styling needed.
+        hideStaleCopies('nozzle-grid-spacing-table');
         var byNozzle = {}, byValve = {}, byPort = {};
         entries.forEach(function (entry) {
             if (entry.nozzle !== null) (byNozzle[entry.nozzle] = byNozzle[entry.nozzle] || []).push(entry);
@@ -2196,11 +2215,61 @@ def _round_targets_to_tenths(record: dict) -> dict:
     return record
 
 
+def _display_shape_name(record: dict) -> str:
+    """The STL cell text: a leading rotation marker (a single compact token,
+    e.g. "↻90°") in front of the name, so a rotated shape is recognizable at
+    a glance straight from the table."""
+    name = str(record.get("name") or "")
+    rotation = _record_rotation(record)
+    if not any(rotation):
+        return name
+    if rotation[0] or rotation[1]:
+        marker = f"↻X{rotation[0]:g}°Y{rotation[1]:g}°Z{rotation[2]:g}°"
+    else:
+        marker = f"↻{rotation[2]:g}°"
+    return f"{marker} {name}"
+
+
+def _strip_rotation_marker(name: str) -> str:
+    """Remove the display-only leading rotation marker before storing a name."""
+    text = name.strip()
+    if text.startswith("↻"):
+        parts = text.split(None, 1)
+        if len(parts) == 2:
+            return parts[1]
+    return name
+
+
+def _split_numbering_defaults(records: list[dict] | None) -> tuple[dict, dict]:
+    """Collision-free Starting Nozzle / Starting Valve for the split panel.
+
+    Splitting assigns a RUN of sequential numbers from the starting values,
+    so the defaults sit past every number in use — otherwise a default
+    split silently lands pieces on other shapes' nozzles (accidentally
+    forming multi-material assemblies) and reuses their valves.
+    """
+    records = records or []
+    nozzles = [
+        _record_nozzle_number(record, int(record.get("idx", position) or position))
+        for position, record in enumerate(records, start=1)
+    ]
+    valves = [_coerce_int(record.get("valve"), 0) for record in records]
+    next_nozzle = (max(nozzles) + 1) if nozzles else 1
+    next_valve = max([valve for valve in valves if valve > 0] + [3]) + 1
+    return gr.update(value=next_nozzle), gr.update(value=next_valve)
+
+
+def refresh_split_sources(records: list[dict] | None) -> tuple:
+    """Split panel refresh: source dropdown + collision-free numbering."""
+    nozzle_update, valve_update = _split_numbering_defaults(records)
+    return _dropdown_update(records), nozzle_update, valve_update
+
+
 def _shape_settings_rows(records: list[dict]) -> list[list[Any]]:
     return [
         [
             record["idx"],
-            record["name"],
+            _display_shape_name(record),
             round(_coerce_float(record.get("target_x"), DEFAULT_TARGET_EXTENTS[0]), 1),
             round(_coerce_float(record.get("target_y"), DEFAULT_TARGET_EXTENTS[1]), 1),
             round(_coerce_float(record.get("target_z"), DEFAULT_TARGET_EXTENTS[2]), 1),
@@ -2233,7 +2302,7 @@ def _apply_shape_settings(records: list[dict], settings_table: Any) -> list[dict
         copy = dict(record)
         row = by_idx.get(int(copy.get("idx", 0)))
         if row:
-            copy["name"] = str(row[1] or copy["name"])
+            copy["name"] = _strip_rotation_marker(str(row[1] or copy["name"]))
             if "original_x" not in copy or "original_y" not in copy or "original_z" not in copy:
                 original_x, original_y, original_z = _default_target_extents_for_stl(str(copy.get("stl_path", "")))
                 copy.setdefault("original_x", original_x)
@@ -4767,6 +4836,12 @@ def export_project_settings(
     lead_in_orientation: str | None,
     nozzle_speed: Any,
     contour_order: str | None = None,
+    split_columns: Any = None,
+    split_rows: Any = None,
+    split_overlapping_layers: Any = None,
+    split_overlapping_rows: Any = None,
+    split_row_overlap_direction: str | None = None,
+    split_overlap: Any = None,
 ) -> tuple[str | None, str]:
     """Write the session's settings to a small JSON file, keyed by STL name.
 
@@ -4804,6 +4879,14 @@ def export_project_settings(
             "lead_in_orientation": str(lead_in_orientation or LEAD_IN_LINE_AUTO),
             "nozzle_speed": _coerce_float(nozzle_speed, 10.0),
             "contour_order": str(contour_order or CONTOUR_ORDER_LAST),
+            "split_columns": max(1, _coerce_int(split_columns, 2)),
+            "split_rows": max(1, _coerce_int(split_rows, 1)),
+            "split_overlapping_layers": bool(split_overlapping_layers),
+            "split_overlapping_rows": bool(split_overlapping_rows),
+            "split_row_overlap_direction": str(
+                split_row_overlap_direction or ROW_OVERLAP_AXES_CHOICES[0]
+            ),
+            "split_overlap": _coerce_float(split_overlap, 0.8),
         },
     }
     settings_path = Path(tempfile.mkdtemp(prefix="pp_settings_")) / "parallelprint_settings.json"
@@ -4827,7 +4910,7 @@ def import_project_settings(
     """
 
     def _skip_options() -> tuple:
-        return tuple(gr.skip() for _ in range(13))
+        return tuple(gr.skip() for _ in range(19))
 
     paths = _uploaded_file_paths(settings_upload)
     if not paths:
@@ -4890,6 +4973,12 @@ def import_project_settings(
         option("scale_mode"),
         option("nozzle_speed"),
         option("contour_order"),
+        option("split_columns"),
+        option("split_rows"),
+        option("split_overlapping_layers"),
+        option("split_overlapping_rows"),
+        option("split_row_overlap_direction"),
+        option("split_overlap"),
     )
 
 
@@ -5808,9 +5897,9 @@ def build_dynamic_demo() -> gr.Blocks:
 
         shape_sync_outputs = [shape_records, shape_settings, selected_shape, gcode_text_source, gcode_source, gcode_downloads, gcode_download_all]
         stl_upload.change(fn=sync_uploaded_shapes, inputs=[stl_upload, shape_records, shape_settings], outputs=shape_sync_outputs).then(
-            fn=lambda records: _dropdown_update(records),
+            fn=refresh_split_sources,
             inputs=[shape_records],
-            outputs=[split_source],
+            outputs=[split_source, split_start_nozzle, split_start_valve],
             queue=False,
         ).then(
             fn=_grid_spacing_table_update,
@@ -5819,9 +5908,9 @@ def build_dynamic_demo() -> gr.Blocks:
             queue=False,
         )
         sync_uploads_button.click(fn=sync_uploaded_shapes, inputs=[stl_upload, shape_records, shape_settings], outputs=shape_sync_outputs).then(
-            fn=lambda records: _dropdown_update(records),
+            fn=refresh_split_sources,
             inputs=[shape_records],
-            outputs=[split_source],
+            outputs=[split_source, split_start_nozzle, split_start_valve],
             queue=False,
         ).then(
             fn=_grid_spacing_table_update,
@@ -5830,9 +5919,9 @@ def build_dynamic_demo() -> gr.Blocks:
             queue=False,
         )
         load_samples_button.click(fn=load_sample_shapes, inputs=[stl_upload, shape_records, shape_settings, sample_set_selector], outputs=[stl_upload, *shape_sync_outputs]).then(
-            fn=lambda records: _dropdown_update(records),
+            fn=refresh_split_sources,
             inputs=[shape_records],
-            outputs=[split_source],
+            outputs=[split_source, split_start_nozzle, split_start_valve],
             queue=False,
         ).then(
             fn=_grid_spacing_table_update,
@@ -5858,9 +5947,9 @@ def build_dynamic_demo() -> gr.Blocks:
             outputs=[stl_upload, *shape_sync_outputs, last_shape_delete_at],
             queue=False,
         ).then(
-            fn=lambda records: _dropdown_update(records),
+            fn=refresh_split_sources,
             inputs=[shape_records],
-            outputs=[split_source],
+            outputs=[split_source, split_start_nozzle, split_start_valve],
             queue=False,
         ).then(
             fn=_grid_spacing_table_update,
@@ -5916,7 +6005,7 @@ def build_dynamic_demo() -> gr.Blocks:
             outputs=[model_viewer, model_details],
         )
 
-        split_refresh_sources.click(fn=lambda records: _dropdown_update(records), inputs=[shape_records], outputs=[split_source], queue=False)
+        split_refresh_sources.click(fn=refresh_split_sources, inputs=[shape_records], outputs=[split_source, split_start_nozzle, split_start_valve], queue=False)
         # .input (user selections only): programmatic dropdown refills after a
         # split must not overwrite the split result message.
         split_source.input(
@@ -5969,6 +6058,13 @@ def build_dynamic_demo() -> gr.Blocks:
             inputs=grid_spacing_refresh_inputs,
             outputs=[nozzle_grid_spacing_table],
             queue=False,
+        ).then(
+            # Fresh pieces claimed a run of nozzles/valves: bump the split
+            # defaults past them so a SECOND split cannot collide either.
+            fn=lambda records: _split_numbering_defaults(records),
+            inputs=[shape_records],
+            outputs=[split_start_nozzle, split_start_valve],
+            queue=False,
         )
         split_undo_button.click(
             fn=undo_last_split,
@@ -5998,6 +6094,11 @@ def build_dynamic_demo() -> gr.Blocks:
             inputs=grid_spacing_refresh_inputs,
             outputs=[nozzle_grid_spacing_table],
             queue=False,
+        ).then(
+            fn=lambda records: _split_numbering_defaults(records),
+            inputs=[shape_records],
+            outputs=[split_start_nozzle, split_start_valve],
+            queue=False,
         )
         assign_valves_button.click(
             fn=assign_unique_valves,
@@ -6023,6 +6124,12 @@ def build_dynamic_demo() -> gr.Blocks:
                 gcode_lead_in_orientation,
                 viz_nozzle_speed,
                 gcode_contour_order,
+                split_columns,
+                split_rows,
+                split_overlapping_layers,
+                split_overlapping_rows,
+                split_row_overlap_direction,
+                split_overlap,
             ],
             outputs=[settings_export_file, settings_status],
             queue=False,
@@ -6047,6 +6154,12 @@ def build_dynamic_demo() -> gr.Blocks:
                 scale_mode,
                 viz_nozzle_speed,
                 gcode_contour_order,
+                split_columns,
+                split_rows,
+                split_overlapping_layers,
+                split_overlapping_rows,
+                split_row_overlap_direction,
+                split_overlap,
             ],
         )
 
@@ -6190,9 +6303,9 @@ def build_dynamic_demo() -> gr.Blocks:
             inputs=layer_preview_inputs,
             outputs=layer_preview_outputs,
         ).then(
-            fn=lambda records: _dropdown_update(records),
+            fn=refresh_split_sources,
             inputs=[shape_records],
-            outputs=[split_source],
+            outputs=[split_source, split_start_nozzle, split_start_valve],
             queue=False,
         ).then(
             fn=check_gcode_staleness,

tests/test_nozzle_spacing.py

@@ -1860,6 +1860,50 @@ def test_apply_shape_rotation_updates_dims_and_reslices(tmp_path) -> None:
     assert (respun[0]["original_x"], respun[0]["original_y"], respun[0]["original_z"]) == (4.0, 10.0, 2.0)
 
 
+def test_split_numbering_defaults_avoid_collisions() -> None:
+    from app import _split_numbering_defaults
+
+    # Shapes on nozzles 5/2/3 with valves 4/9: the split defaults must sit
+    # PAST every number in use (splits assign sequential runs), otherwise a
+    # default split lands pieces on other shapes' nozzles - silently forming
+    # multi-material assemblies - and reuses their valves.
+    records = [
+        {"idx": 1, "name": "a", "nozzle": 5, "valve": 4},
+        {"idx": 2, "name": "b", "nozzle": 2, "valve": 9},
+        {"idx": 3, "name": "c", "nozzle": 3, "valve": 0},
+    ]
+    nozzle_update, valve_update = _split_numbering_defaults(records)
+    assert nozzle_update["value"] == 6
+    assert valve_update["value"] == 10
+
+    # Empty table: the historical defaults.
+    nozzle_update, valve_update = _split_numbering_defaults([])
+    assert nozzle_update["value"] == 1
+    assert valve_update["value"] == 4
+
+
+def test_rotation_marker_shows_in_table_and_strips_on_read() -> None:
+    from app import _apply_shape_settings, _display_shape_name
+
+    record = {
+        "idx": 1, "name": "bar", "stl_path": "bar.stl",
+        "original_x": 10.0, "original_y": 4.0, "original_z": 2.0,
+        "target_x": 10.0, "target_y": 4.0, "target_z": 2.0,
+        "pressure": 25.0, "valve": 4, "nozzle": 1, "port": 1,
+        "color": "#111111", "rotation": (0.0, 0.0, 90.0),
+    }
+    # The STL cell carries a visible LEADING rotation marker...
+    assert _display_shape_name(record) == "↻90° bar"
+    rows = _shape_settings_rows([record])
+    assert rows[0][1] == "↻90° bar"
+    # ...which is display-only: reading the table back stores the clean name.
+    updated = _apply_shape_settings([record], rows)
+    assert updated[0]["name"] == "bar"
+    # Unrotated shapes show the plain name.
+    record["rotation"] = None
+    assert _display_shape_name(record) == "bar"
+
+
 def test_rotate_all_shapes_at_once(tmp_path) -> None:
     import trimesh
 
@@ -1910,6 +1954,8 @@ def test_project_settings_export_import_round_trip(tmp_path) -> None:
     settings_path, status = export_project_settings(
         records, None, 0.4, 0.4, None, "Circle Spiral raster", False, 1.2,
         6.0, 7.0, 4, "Down", "Horizontal", 15.0,
+        split_columns=3, split_rows=2, split_overlapping_rows=True,
+        split_overlap=1.5,
     )
     assert settings_path and "2 shape(s)" in status
 
@@ -1930,6 +1976,10 @@ def test_project_settings_export_import_round_trip(tmp_path) -> None:
     assert option_updates[2]["value"] == 1.2
     assert option_updates[8]["value"] == 0.4  # layer height
     assert option_updates[11]["value"] == 15.0  # nozzle speed
+    assert option_updates[13]["value"] == 3  # split columns
+    assert option_updates[14]["value"] == 2  # split rows
+    assert option_updates[16]["value"] is True  # overlapping rows
+    assert option_updates[18]["value"] == 1.5  # overlap mm
 
     # A file listed in the export but not loaded is reported.
     partial = import_project_settings([settings_path], _records_from_files(["egg_inside.stl"], None), None)