Files
bambuddy/backend/app/utils/threemf_tools.py
T
maziggy c1f69ee0cc fix(slicer): wrong-printer slicing + sliced-archive filament list + per-instance MakerWorld compat
Five stacked slice-pipeline bugs that each made the modal's profile picker
  theatrical for 3MF inputs:

  (1) `_strip_3mf_embedded_settings` removed `model_settings.config` /
      `slice_info.config` / `cut_information.xml` along with
      `project_settings.config`. The CLI silently exited after
      "Initializing StaticPrintConfigs" — exit 0, no result.json — and
      Bambuddy masked the failure by re-running with embedded settings
      and the source's bound printer. Strip removed from the dispatch
      path entirely.

  (2) Standard-tier preset stubs lacked the `type` field, so the CLI
      rejected `--load-settings` with rc=-5 ("input preset file is
      invalid") and the same masking fallback fired. Added
      `_SLOT_TO_PROFILE_TYPE` so each stub carries the right
      machine/process/filament discriminator.

  (3) Sliced-archive cards listed every project-wide AMS slot (16+
      swatches for a 2-color print). `slice_and_persist_as_archive` now
      reads `filament_type` / `filament_color` from the sliced output's
      `slice_info.config` (which `ThreeMFParser` already gates on
      `used_g > 0`) instead of inheriting from the source archive.

  (4) SliceModal had no warning when the picked printer profile didn't
      match the source 3MF — the CLI rejects cross-printer slices
      (rc=-16) and fell back to embedded settings, producing wrong-printer
      g-code that errored at print dispatch. Plates response now exposes
      `source_printer_model`; the modal compares against the picked
      profile name and disables Slice + shows an inline warning on
      mismatch.

  (5) MakerWorld URL-paste resolver listed plate instances without
      showing which printer each was sliced for (`/instances/hits`
      omits compatibility info that lives on `design.instances[]
      .extention.modelInfo`). The resolve route now joins both payloads
      by instance ID and forwards `compatibility` + `otherCompatibility`
      onto each hit; the MakerWorld page renders "Sliced for {primary}"
      + "Also marked compatible: ..." per row.

  Tests: 6 unit tests for `extract_source_printer_model_from_3mf`, 1 for
  filtered filament metadata via ThreeMFParser, 2 for makerworld resolve
  compat-merge (happy path + missing modelInfo), 3 frontend SliceModal
  tests for the printer-mismatch warning + Slice-disabled gate. New i18n
  keys `slice.printerMismatch`, `makerworld.slicedFor`,
  `makerworld.alsoCompatible` across all 8 locales.
2026-04-28 13:58:56 +02:00

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"""3MF file parsing utilities for filament tracking.
This module provides functions to parse Bambu Lab 3MF files and extract
per-layer filament usage data from the embedded G-code. This enables
accurate partial usage reporting for multi-material prints.
"""
import json
import logging
import math
import re
import zipfile
from pathlib import Path
import defusedxml.ElementTree as ET
logger = logging.getLogger(__name__)
# Default filament properties
DEFAULT_FILAMENT_DIAMETER = 1.75 # mm
DEFAULT_FILAMENT_DENSITY = 1.24 # g/cm³ (PLA)
def parse_gcode_layer_filament_usage(gcode_content: str) -> dict[int, dict[int, float]]:
"""Parse G-code to extract per-layer, per-filament cumulative extrusion in mm.
This function tracks filament extrusion across layers and tool changes,
building a cumulative usage map that can be used to calculate partial
usage at any layer.
Args:
gcode_content: The raw G-code content as a string
Returns:
A nested dictionary mapping layer numbers to filament usage:
{layer: {filament_id: cumulative_mm}, ...}
Example:
{0: {0: 125.5}, 1: {0: 250.0, 1: 50.0}, 2: {0: 375.0, 1: 150.0}}
This shows:
- Layer 0: filament 0 used 125.5mm cumulative
- Layer 1: filament 0 used 250mm cumulative, filament 1 used 50mm
- Layer 2: filament 0 used 375mm cumulative, filament 1 used 150mm
G-code commands parsed:
- M73 L<layer>: Layer change marker
- M620 S<filament>: Filament/tool change (S255 = unload)
- G0/G1/G2/G3 E<amount>: Extrusion moves
"""
layer_filaments: dict[int, dict[int, float]] = {}
current_layer = 0
active_filament: int | None = None
cumulative_extrusion: dict[int, float] = {} # filament_id -> total mm
for line in gcode_content.splitlines():
line = line.strip()
if not line:
continue
# Handle comments - skip but check for layer markers
if line.startswith(";"):
# Some slicers use comment-based layer markers
# e.g., "; CHANGE_LAYER" or ";LAYER_CHANGE"
continue
# Split line into command and inline comment
if ";" in line:
line = line.split(";")[0].strip()
# Extract command and parameters
parts = line.split()
if not parts:
continue
cmd = parts[0].upper()
# Layer change: M73 L<layer>
# Bambu printers use M73 with L parameter for layer indication
if cmd == "M73":
for part in parts[1:]:
part_upper = part.upper()
if part_upper.startswith("L"):
try:
new_layer = int(part[1:])
# Save current state before layer change
if cumulative_extrusion:
layer_filaments[current_layer] = cumulative_extrusion.copy()
current_layer = new_layer
except ValueError:
pass # Skip G-code lines with unparseable layer numbers
# Filament change: M620 S<filament>
# Bambu uses M620 for AMS filament switching
# S255 means full unload (no active filament)
elif cmd == "M620":
for part in parts[1:]:
part_upper = part.upper()
if part_upper.startswith("S"):
filament_str = part[1:]
if filament_str == "255":
# Full unload - no active filament
active_filament = None
else:
try:
# Extract digits (e.g., "0A" -> 0, "1" -> 1)
match = re.match(r"(\d+)", filament_str)
if match:
active_filament = int(match.group(1))
except (ValueError, AttributeError):
pass # Skip unparseable filament switch commands
# Extrusion moves: G0/G1/G2/G3 with E parameter
# Only G1 typically has extrusion, but check all for safety
elif cmd in ("G0", "G1", "G2", "G3"):
if active_filament is None:
continue
for part in parts[1:]:
part_upper = part.upper()
if part_upper.startswith("E"):
try:
extrusion = float(part[1:])
# Only count positive extrusion (not retractions)
if extrusion > 0:
current = cumulative_extrusion.get(active_filament, 0)
cumulative_extrusion[active_filament] = current + extrusion
except ValueError:
pass # Skip G-code lines with unparseable extrusion values
# Save final layer state
if cumulative_extrusion:
layer_filaments[current_layer] = cumulative_extrusion.copy()
return layer_filaments
def mm_to_grams(
length_mm: float,
diameter_mm: float = DEFAULT_FILAMENT_DIAMETER,
density_g_cm3: float = DEFAULT_FILAMENT_DENSITY,
) -> float:
"""Convert filament length in mm to weight in grams.
Uses the formula: mass = volume × density
where volume = π × r² × length
Args:
length_mm: Length of filament in millimeters
diameter_mm: Filament diameter in millimeters (default: 1.75)
density_g_cm3: Material density in g/cm³ (default: 1.24 for PLA)
Returns:
Weight in grams
"""
radius_cm = (diameter_mm / 2) / 10 # Convert mm to cm
length_cm = length_mm / 10 # Convert mm to cm
volume_cm3 = math.pi * radius_cm * radius_cm * length_cm
return volume_cm3 * density_g_cm3
def extract_layer_filament_usage_from_3mf(file_path: Path) -> dict[int, dict[int, float]] | None:
"""Extract per-layer filament usage from a 3MF file's embedded G-code.
Args:
file_path: Path to the 3MF file
Returns:
Dictionary mapping layers to filament usage, or None if parsing fails.
Format: {layer: {filament_id: cumulative_mm}, ...}
"""
try:
with zipfile.ZipFile(file_path, "r") as zf:
# Find G-code file(s) - usually plate_1.gcode or Metadata/plate_1.gcode
gcode_files = [f for f in zf.namelist() if f.endswith(".gcode")]
if not gcode_files:
return None
# Use the first G-code file (typically only one per 3MF export)
gcode_path = gcode_files[0]
gcode_content = zf.read(gcode_path).decode("utf-8", errors="ignore")
return parse_gcode_layer_filament_usage(gcode_content)
except Exception:
return None
def get_cumulative_usage_at_layer(
layer_usage: dict[int, dict[int, float]],
target_layer: int,
) -> dict[int, float]:
"""Get cumulative filament usage (in mm) up to and including target_layer.
Args:
layer_usage: The output from parse_gcode_layer_filament_usage()
target_layer: The layer number to get usage for
Returns:
Dictionary of {filament_id: cumulative_mm} for each filament used
up to target_layer. Returns empty dict if no data available.
"""
if not layer_usage:
return {}
# Find the highest recorded layer <= target_layer
# (we store snapshots at layer changes, so we need the closest one)
relevant_layers = [layer for layer in layer_usage if layer <= target_layer]
if not relevant_layers:
return {}
max_layer = max(relevant_layers)
return layer_usage.get(max_layer, {})
def extract_filament_properties_from_3mf(file_path: Path) -> dict[int, dict]:
"""Extract filament properties (density, diameter, type) from 3MF metadata.
Args:
file_path: Path to the 3MF file
Returns:
Dictionary mapping filament IDs to their properties:
{filament_id: {"diameter": 1.75, "density": 1.24, "type": "PLA"}, ...}
Note: filament_id is 1-based (matches slot_id in slice_info.config)
"""
properties: dict[int, dict] = {}
try:
with zipfile.ZipFile(file_path, "r") as zf:
# Try slice_info.config first for filament types
if "Metadata/slice_info.config" in zf.namelist():
content = zf.read("Metadata/slice_info.config").decode()
root = ET.fromstring(content)
for f in root.findall(".//filament"):
try:
# id is 1-based in slice_info.config
fid = int(f.get("id", 0))
properties[fid] = {
"type": f.get("type", "PLA"),
"diameter": DEFAULT_FILAMENT_DIAMETER,
"density": DEFAULT_FILAMENT_DENSITY,
}
except ValueError:
pass # Skip filament entries with unparseable IDs
# Try project_settings.config for density values
if "Metadata/project_settings.config" in zf.namelist():
content = zf.read("Metadata/project_settings.config").decode()
try:
data = json.loads(content)
densities = data.get("filament_density", [])
for i, density in enumerate(densities):
# project_settings uses 0-based indexing, convert to 1-based
fid = i + 1
if fid not in properties:
properties[fid] = {
"type": "",
"diameter": DEFAULT_FILAMENT_DIAMETER,
}
try:
properties[fid]["density"] = float(density)
except (ValueError, TypeError):
properties[fid]["density"] = DEFAULT_FILAMENT_DENSITY
except json.JSONDecodeError:
pass # Skip malformed project_settings.config JSON
except Exception:
pass # Return whatever properties were collected before the error
return properties
def extract_nozzle_mapping_from_3mf(zf: zipfile.ZipFile) -> dict[int, int] | None:
"""Extract per-slot nozzle/extruder mapping from a 3MF file.
On dual-nozzle printers (H2D, H2D Pro), each filament slot is assigned to a
specific nozzle. The slicer may override user preferences when using "Auto For
Flush" mode, so the actual assignment comes from slice_info.config group_id
attributes, not from the user's filament_nozzle_map preference.
Priority:
1. group_id on <filament> elements in slice_info.config (actual assignment)
2. filament_nozzle_map in project_settings.config (user preference fallback)
Both are mapped through physical_extruder_map to get MQTT extruder IDs (0=right, 1=left).
Args:
zf: An open ZipFile of the 3MF archive
Returns:
Dictionary mapping {slot_id: extruder_id} for dual-nozzle files,
or None if single-nozzle, missing data, or parse error.
"""
try:
if "Metadata/project_settings.config" not in zf.namelist():
return None
content = zf.read("Metadata/project_settings.config").decode()
data = json.loads(content)
physical_extruder_map = data.get("physical_extruder_map")
if not physical_extruder_map or len(physical_extruder_map) <= 1:
return None # Single-nozzle printer
# Check if only one extruder is active.
# If so, we can skip the mapping and just assign all slots to that extruder.
# extruder_nozzle_stats format: ["Standard#0|High Flow#0", "Standard#1"]
# Each entry = one extruder. Format: <NozzleVolumeType>#<count>[|...]
# #N is the count of physical nozzles of that type (0 = none installed).
# Types: Standard, High Flow, Hybrid, TPU High Flow
active_extruders = []
for stats_str in data.get("extruder_nozzle_stats") or []:
nozzle_counts = [n.partition("#")[2] for n in stats_str.split("|")]
active_extruders.append(1 if any(c not in ("0", "") for c in nozzle_counts) else 0)
if sum(active_extruders) == 1:
nozzle_mapping: dict[int, int] = {}
active_idx = active_extruders.index(1)
target_extruder = int(physical_extruder_map[active_idx])
if "Metadata/slice_info.config" in zf.namelist():
si_content = zf.read("Metadata/slice_info.config").decode()
si_root = ET.fromstring(si_content)
for filament_elem in si_root.findall(".//filament"):
try:
nozzle_mapping[int(filament_elem.get("id"))] = target_extruder
except (ValueError, TypeError):
pass
return nozzle_mapping or None
# Priority 1: Use group_id from slice_info filament elements.
# This reflects the actual slicer assignment (respects "Auto For Flush").
nozzle_mapping: dict[int, int] = {}
if "Metadata/slice_info.config" in zf.namelist():
si_content = zf.read("Metadata/slice_info.config").decode()
si_root = ET.fromstring(si_content)
for filament_elem in si_root.findall(".//filament"):
group_id_str = filament_elem.get("group_id")
filament_id_str = filament_elem.get("id")
if group_id_str is not None and filament_id_str:
try:
group_id = int(group_id_str)
slot_id = int(filament_id_str)
if group_id < len(physical_extruder_map):
nozzle_mapping[slot_id] = int(physical_extruder_map[group_id])
except (ValueError, TypeError, IndexError):
pass
if nozzle_mapping:
return nozzle_mapping
# Priority 2: Fall back to filament_nozzle_map (user preference).
# This is correct when the user manually assigned nozzles, but may be
# wrong when the slicer overrides via "Auto For Flush".
filament_nozzle_map = data.get("filament_nozzle_map")
if not filament_nozzle_map:
return None
for i, slicer_ext_str in enumerate(filament_nozzle_map):
slot_id = i + 1
try:
slicer_ext = int(slicer_ext_str)
if slicer_ext < len(physical_extruder_map):
nozzle_mapping[slot_id] = int(physical_extruder_map[slicer_ext])
except (ValueError, TypeError, IndexError):
pass
return nozzle_mapping if nozzle_mapping else None
except Exception:
return None
def extract_filament_usage_from_3mf(file_path: Path, plate_id: int | None = None) -> list[dict]:
"""Extract per-filament total usage from 3MF slice_info.config.
This extracts the slicer-estimated total usage per filament slot,
not the per-layer breakdown.
Args:
file_path: Path to the 3MF file
plate_id: Optional plate index to filter for (for multi-plate files)
Returns:
List of filament usage dictionaries:
[{"slot_id": 1, "used_g": 50.5, "type": "PLA", "color": "#FF0000"}, ...]
"""
filament_usage = []
try:
with zipfile.ZipFile(file_path, "r") as zf:
if "Metadata/slice_info.config" not in zf.namelist():
return []
content = zf.read("Metadata/slice_info.config").decode()
root = ET.fromstring(content)
if plate_id is not None:
# Find the plate element with matching index
for plate_elem in root.findall(".//plate"):
plate_index = None
for meta in plate_elem.findall("metadata"):
if meta.get("key") == "index":
try:
plate_index = int(meta.get("value", "0"))
except ValueError:
pass
break
if plate_index == plate_id:
for f in plate_elem.findall("filament"):
filament_id = f.get("id")
used_g = f.get("used_g", "0")
try:
used_amount = float(used_g)
if filament_id:
filament_usage.append(
{
"slot_id": int(filament_id),
"used_g": used_amount,
"type": f.get("type", ""),
"color": f.get("color", ""),
}
)
except (ValueError, TypeError):
pass
break
else:
# No plate_id specified - extract all filaments
for f in root.findall(".//filament"):
filament_id = f.get("id")
used_g = f.get("used_g", "0")
try:
used_amount = float(used_g)
if filament_id:
filament_usage.append(
{
"slot_id": int(filament_id),
"used_g": used_amount,
"type": f.get("type", ""),
"color": f.get("color", ""),
}
)
except (ValueError, TypeError):
pass # Skip filament entries with unparseable usage values
except Exception:
pass # Return whatever usage data was collected before the error
return filament_usage
# Header values exposed as `{placeholder}` substitutions inside snippets.
# Aliases let users write Prusa-style names (`{max_layer_z}`) that map onto
# Bambu/Orca header keys (`max_z_height`).
_HEADER_PLACEHOLDER_ALIASES = {
"max_layer_z": "max_z_height",
"max_print_height": "max_z_height",
"total_layers": "total_layer_number",
}
_HEADER_KEY_RE = re.compile(r"^;\s*([^:]+?)\s*:\s*(.+?)\s*$")
_PLACEHOLDER_RE = re.compile(r"\{([a-zA-Z_][a-zA-Z0-9_]*)\}")
_START_GCODE_END_MARKER = "; MACHINE_START_GCODE_END"
def _parse_3mf_gcode_header(content: str) -> dict[str, str]:
"""Parse the `; HEADER_BLOCK_START..END` block into a normalised dict.
Keys are lowercased, ` [units]` suffixes stripped, and spaces converted
to underscores so callers can look up `total_layer_number` regardless of
whether the source line is `; total layer number: 80` or
`; total filament length [mm] : 12155.34`.
"""
header: dict[str, str] = {}
in_header = False
for raw_line in content.splitlines():
line = raw_line.strip()
if line == "; HEADER_BLOCK_START":
in_header = True
continue
if line == "; HEADER_BLOCK_END":
break
if not in_header:
continue
m = _HEADER_KEY_RE.match(line)
if not m:
continue
key, value = m.group(1), m.group(2)
key = re.sub(r"\s*\[[^\]]*\]\s*$", "", key)
key = key.strip().lower().replace(" ", "_")
header[key] = value
return header
def _substitute_placeholders(snippet: str, header: dict[str, str]) -> str:
"""Replace `{var}` placeholders with header values, leaving unknowns intact."""
def repl(m: re.Match) -> str:
name = m.group(1)
value = header.get(name)
if value is None:
alias = _HEADER_PLACEHOLDER_ALIASES.get(name)
if alias is not None:
value = header.get(alias)
if value is None:
logger.warning(
"G-code injection: placeholder {%s} not found in 3MF header; leaving as-is",
name,
)
return m.group(0)
return value
return _PLACEHOLDER_RE.sub(repl, snippet)
def _inject_start_at_marker(content: str, snippet: str) -> str:
"""Insert snippet immediately before `; MACHINE_START_GCODE_END`.
The marker sits at the bottom of the printer's startup block — bed heat,
homing, and nozzle prime are already done, so injected snippets land in
the same place a slicer-side custom-start-gcode would. Falls back to
prepending if the marker isn't present (older files / non-Bambu slicers).
"""
marker_idx = content.find(_START_GCODE_END_MARKER)
if marker_idx == -1:
logger.warning(
"G-code injection: '%s' not found, prepending start snippet to whole file",
_START_GCODE_END_MARKER,
)
return snippet.rstrip("\n") + "\n" + content
line_start = content.rfind("\n", 0, marker_idx)
line_start = 0 if line_start == -1 else line_start + 1
return content[:line_start] + snippet.rstrip("\n") + "\n" + content[line_start:]
def inject_gcode_into_3mf(
source_path: Path,
plate_id: int,
start_gcode: str | None,
end_gcode: str | None,
):
"""Create a temp copy of a 3MF with G-code injected at start/end.
Snippets support `{placeholder}` substitution against values parsed from
the 3MF G-code header block (e.g. `{max_layer_z}` → `16.00`). Start
snippets are anchored to the `; MACHINE_START_GCODE_END` marker so they
run after the printer's own startup (#422). End snippets are appended
after the last line of the print.
Args:
source_path: Path to the original 3MF file.
plate_id: Plate number (1-indexed) to inject into.
start_gcode: G-code to insert after printer startup, or None.
end_gcode: G-code to append, or None.
Returns:
Path to temp file with injected G-code, or None if injection failed.
Caller is responsible for cleaning up the temp file.
"""
import tempfile
if not start_gcode and not end_gcode:
return None
try:
# Find the target gcode file inside the 3MF
with zipfile.ZipFile(source_path, "r") as zf:
all_gcode = [f for f in zf.namelist() if f.endswith(".gcode")]
if not all_gcode:
return None
# Try plate-specific gcode file first
target_gcode = None
plate_pattern = f"plate_{plate_id}.gcode"
for f in all_gcode:
if f.endswith(plate_pattern):
target_gcode = f
break
# Fall back to first gcode file
if target_gcode is None:
target_gcode = all_gcode[0]
# Read and modify gcode content
gcode_content = zf.read(target_gcode).decode("utf-8", errors="ignore")
header = _parse_3mf_gcode_header(gcode_content)
if start_gcode:
resolved = _substitute_placeholders(start_gcode, header)
gcode_content = _inject_start_at_marker(gcode_content, resolved)
if end_gcode:
resolved = _substitute_placeholders(end_gcode, header)
gcode_content = gcode_content.rstrip("\n") + "\n" + resolved + "\n"
# Write modified 3MF to temp file
with tempfile.NamedTemporaryFile(delete=False, suffix=".3mf") as tmp:
tmp_path = Path(tmp.name)
with zipfile.ZipFile(tmp_path, "w", zipfile.ZIP_DEFLATED) as zf_write:
for item in zf.namelist():
info = zf.getinfo(item)
if item == target_gcode:
zf_write.writestr(info, gcode_content.encode("utf-8"))
else:
zf_write.writestr(info, zf.read(item))
return tmp_path
except Exception:
# Clean up temp file on error
if "tmp_path" in locals() and tmp_path.exists():
tmp_path.unlink(missing_ok=True)
return None
def extract_source_printer_model_from_3mf(zf: zipfile.ZipFile) -> str | None:
"""Source 3MF's bound printer model from ``Metadata/project_settings.config``.
Returns e.g. ``"Bambu Lab A1"`` when the project was built for an A1, or
``None`` when the file lacks the metadata or the field is absent. The
SliceModal uses this to warn the user before slicing if the chosen
printer profile targets a different model — the slicer CLI rejects
cross-printer slicing with rc=-16 and the result, when the strip + load
fallback masks it, is a misleadingly-tagged archive.
"""
if "Metadata/project_settings.config" not in zf.namelist():
return None
try:
proj = json.loads(zf.read("Metadata/project_settings.config").decode())
except (ValueError, OSError):
return None
if not isinstance(proj, dict):
return None
model = proj.get("printer_model")
if isinstance(model, str) and model.strip():
return model.strip()
# Some older Bambu Studio exports stored the model under
# ``printer_settings_id`` (e.g. "Bambu Lab A1 0.4 nozzle"); strip the
# nozzle suffix to get the canonical model name. Best-effort — if the
# field doesn't follow the convention we leave it as-is.
settings_id = proj.get("printer_settings_id")
if isinstance(settings_id, str) and settings_id.strip():
# Drop trailing " 0.4 nozzle" / " 0.2 nozzle" / etc.
return re.sub(r"\s+0\.\d+\s+nozzle$", "", settings_id.strip())
return None
def extract_project_filaments_from_3mf(zf: zipfile.ZipFile) -> list[dict]:
"""Project-wide AMS slot config from ``Metadata/project_settings.config``.
Returns one dict per configured AMS slot in slot order (1-indexed), with
``type`` and ``color`` populated from the project's ``filament_type`` and
``filament_colour`` arrays. ``used_grams`` / ``used_meters`` are 0 because
project_settings carries the configuration, not per-print usage — the
fields exist for shape compatibility with the slice_info-derived list.
The SliceModal needs this on **unsliced** project files: slice_info.config
is empty until Bambu Studio has actually sliced the project, but the user
can still pick filament profiles for a slice we're about to perform.
"""
if "Metadata/project_settings.config" not in zf.namelist():
return []
try:
proj = json.loads(zf.read("Metadata/project_settings.config").decode())
except (ValueError, OSError):
return []
if not isinstance(proj, dict):
return []
types_arr = proj.get("filament_type") or []
colors_arr = proj.get("filament_colour") or []
slot_count = max(
len(types_arr) if isinstance(types_arr, list) else 0, len(colors_arr) if isinstance(colors_arr, list) else 0
)
out: list[dict] = []
for i in range(slot_count):
out.append(
{
"slot_id": i + 1,
"type": types_arr[i] if i < len(types_arr) and isinstance(types_arr[i], str) else "",
"color": colors_arr[i] if i < len(colors_arr) and isinstance(colors_arr[i], str) else "",
"used_grams": 0,
"used_meters": 0,
}
)
return out
_PAINT_COLOR_ATTR_RE = re.compile(rb'paint_color="([0-9A-Fa-f]+)"')
# Painted-face quadtree leaves include both real filament assignments and
# tiny edit artifacts (single-leaf accidents from "tried a colour, undid,
# repainted with a different one"). The threshold's only job is dropping
# accidents — anything the user spent meaningful effort on must survive.
# 5% of an object's painted triangles is well below any 60/40 / 70/30 /
# 33/33/33 split a real two- or three-colour print would hit, so all
# intentional colours are kept; one-off single-leaf paints (typically
# 0.1-1.5% in observed projects) are filtered. Note that this fallback
# path runs ONLY when the preview-slice path can't reach the sidecar; in
# the normal flow the slicer's own pruning produces the canonical list and
# this threshold isn't reached.
_PAINT_NOISE_THRESHOLD = 0.05
def extract_plate_extruder_set_from_3mf(zf: zipfile.ZipFile, plate_id: int) -> set[int]:
"""Extruder/AMS slot indices (1-indexed) used by objects on ``plate_id``.
Three sources are unioned because Bambu Studio splits per-object extruder
info across THREE places depending on how the user assigned colours:
1. ``model_settings.config`` — top-level ``<metadata key="extruder">``
on each ``<object>`` (the "default extruder" for the whole object).
2. ``model_settings.config`` — per-``<part>`` ``<metadata key="extruder">``
overrides (used when the user split an object into multiple parts
with distinct filaments).
3. ``3D/Objects/object_*.model`` — ``paint_color`` attributes on
individual ``<triangle>`` elements (used when the user "painted" a
face with a different filament). The encoding is a hex string where
each nibble is a TriangleSelector tree node: ``0`` = unpainted leaf,
``F`` = branch (4 children follow), ``1``..``E`` = leaf painted with
extruder N. We don't decode the tree — every leaf-paint nibble in
the string IS the extruder number, so a flat scan over hex chars
yields the correct set without recursive parsing.
Without (3) the painted-face data is invisible: model_settings says
every object on a multi-color plate uses extruder 1 by default but the
actual print uses 3, 4, 12 etc. via face paint, so the SliceModal would
render only one filament dropdown for what's clearly a multi-colour
print (#1150 follow-up).
"""
if "Metadata/model_settings.config" not in zf.namelist():
return set()
try:
root = ET.fromstring(zf.read("Metadata/model_settings.config").decode())
except (ET.ParseError, OSError):
return set()
# Pass 1: object → set of extruders from XML metadata (sources 1 + 2)
# plus the per-object .model file path so we can later scan source 3.
object_extruders: dict[str, set[int]] = {}
object_model_paths: dict[str, list[str]] = {}
for obj_elem in root.findall(".//object"):
obj_id = obj_elem.get("id")
if not obj_id:
continue
extruders: set[int] = set()
top = obj_elem.find("metadata[@key='extruder']")
if top is not None:
try:
v = int(top.get("value", "0"))
if v > 0:
extruders.add(v)
except (ValueError, TypeError):
pass
for part_elem in obj_elem.findall(".//part"):
part_ext = part_elem.find("metadata[@key='extruder']")
if part_ext is None:
continue
try:
v = int(part_ext.get("value", "0"))
if v > 0:
extruders.add(v)
except (ValueError, TypeError):
pass
object_extruders[obj_id] = extruders
# Pass 2: 3dmodel.model maps each <object id="N"> to its component
# .model file path(s). Bambu wraps object IDs that match
# model_settings.config IDs around <components><component
# path="/3D/Objects/object_K.model" objectid="..." /></components>.
# Strip xmlns prefixes on attributes so ElementTree can find them
# without namespace gymnastics — `p:path` becomes `path` etc.
if "3D/3dmodel.model" in zf.namelist():
try:
raw = zf.read("3D/3dmodel.model").decode()
stripped = re.sub(r'xmlns:?\w*="[^"]*"', "", raw)
stripped = re.sub(r"<(/?)\w+:", r"<\1", stripped)
stripped = re.sub(r" \w+:(\w+=)", r" \1", stripped)
model_root = ET.fromstring(stripped)
for obj_elem in model_root.findall(".//object"):
oid = obj_elem.get("id")
if not oid:
continue
comps = obj_elem.find("components")
if comps is None:
continue
paths = []
for c in comps.findall("component"):
p = c.get("path")
if p:
paths.append(p.lstrip("/"))
if paths:
object_model_paths[oid] = paths
except (ET.ParseError, OSError):
pass # No 3dmodel — paint scan just won't apply
# Pass 3: scan paint_color attrs in each per-object .model file. Cache
# by file path because two objects often share the same component tree.
paint_cache: dict[str, set[int]] = {}
def _scan_paint(path: str) -> set[int]:
if path in paint_cache:
return paint_cache[path]
out: set[int] = set()
if path not in zf.namelist():
paint_cache[path] = out
return out
try:
data = zf.read(path)
except OSError:
paint_cache[path] = out
return out
# Per-extruder triangle coverage. Each painted triangle may have
# multiple leaf nibbles (the quadtree subdivides the face into
# painted regions); we count one triangle per unique extruder per
# match so the resulting fraction is "what share of painted
# triangles include at least one leaf with extruder N". Noise from
# one-off edit artifacts is filtered out at the threshold below.
extruder_triangles: dict[int, int] = {}
total_painted = 0
for match in _PAINT_COLOR_ATTR_RE.finditer(data):
total_painted += 1
seen: set[int] = set()
for ch in match.group(1):
# Hex digit → 4-bit value. 0 = unpainted leaf, F = branch
# (decoded recursively but children are encoded inline, so
# we'll see them on later iterations). 1-E = leaf painted
# with extruder N.
if ch in b"123456789":
seen.add(ch - 0x30)
elif ch in b"ABCDEabcde":
seen.add((ch & 0x4F) - 0x37)
for e in seen:
extruder_triangles[e] = extruder_triangles.get(e, 0) + 1
if total_painted > 0:
cutoff = max(1, int(total_painted * _PAINT_NOISE_THRESHOLD))
for ext, count in extruder_triangles.items():
if count >= cutoff:
out.add(ext)
paint_cache[path] = out
return out
# Walk plates — collect extruders for objects on the requested plate.
used: set[int] = set()
for plate_elem in root.findall(".//plate"):
plater_id = None
for meta in plate_elem.findall("metadata"):
if meta.get("key") == "plater_id":
try:
plater_id = int(meta.get("value", ""))
except (ValueError, TypeError):
pass
break
if plater_id != plate_id:
continue
for inst in plate_elem.findall("model_instance"):
for inst_meta in inst.findall("metadata"):
if inst_meta.get("key") != "object_id":
continue
obj_id = inst_meta.get("value")
if not obj_id:
continue
used.update(object_extruders.get(obj_id, set()))
for path in object_model_paths.get(obj_id, []):
used.update(_scan_paint(path))
break
return used