Meshy 3d Printing

Image-to-3D Print Pipeline

Print Download + Slicer Script

Append this to the reusable script template from meshy-3d-generation:

import subprocess, shutil

# After task SUCCEEDED, download OBJ format for printing
obj_url = task["model_urls"].get("obj")
if not obj_url:
    print("OBJ format not available. Available:", list(task["model_urls"].keys()))
    print("Download GLB and import manually into your slicer.")
    obj_url = task["model_urls"].get("glb")

obj_path = os.path.join(project_dir, "model.obj")
download(obj_url, obj_path)

# --- Post-process OBJ for slicer compatibility ---
def fix_obj_for_printing(input_path, output_path=None, target_height_mm=75.0):
    """
    Fix OBJ coordinate system, scale, and position for 3D printing slicers.
    - Rotates from glTF Y-up to slicer Z-up: (x, y, z) -> (x, -z, y)
    - Scales model to target_height_mm (default 75mm)
    - Centers model on XY plane (so slicer places it at bed center)
    - Aligns model bottom to Z=0 (origin at bottom)
    """
    if output_path is None:
        output_path = input_path

    lines = open(input_path, "r").readlines()

    # Pass 1: rotate vertices Y-up -> Z-up, collect bounds
    rotated = []
    min_x, max_x = float("inf"), float("-inf")
    min_y, max_y = float("inf"), float("-inf")
    min_z, max_z = float("inf"), float("-inf")
    for line in lines:
        if line.startswith("v "):
            parts = line.split()
            x, y, z = float(parts[1]), float(parts[2]), float(parts[3])
            # glTF Y-up to Z-up: (x, y, z) -> (x, -z, y)
            rx, ry, rz = x, -z, y
            min_x, max_x = min(min_x, rx), max(max_x, rx)
            min_y, max_y = min(min_y, ry), max(max_y, ry)
            min_z, max_z = min(min_z, rz), max(max_z, rz)
            rotated.append(("v", rx, ry, rz, parts[4:]))  # keep extra data (e.g. colors)
        elif line.startswith("vn "):
            parts = line.split()
            nx, ny, nz = float(parts[1]), float(parts[2]), float(parts[3])
            rotated.append(("vn", nx, -nz, ny, []))
        else:
            rotated.append(("line", line))

    # Calculate scale, XY center offset, and Z bottom offset
    model_height = max_z - min_z
    scale = target_height_mm / model_height if model_height > 1e-6 else 1.0
    x_offset = -(min_x + max_x) / 2.0 * scale
    y_offset = -(min_y + max_y) / 2.0 * scale
    z_offset = -(min_z * scale)

    # Pass 2: write transformed OBJ
    with open(output_path, "w") as f:
        for item in rotated:
            if item[0] == "v":
                _, rx, ry, rz, extra = item
                tx = rx * scale + x_offset
                ty = ry * scale + y_offset
                tz = rz * scale + z_offset
                extra_str = " " + " ".join(extra) if extra else ""
                f.write(f"v {tx:.6f} {ty:.6f} {tz:.6f}{extra_str}\n")
            elif item[0] == "vn":
                _, nx, ny, nz, _ = item
                f.write(f"vn {nx:.6f} {ny:.6f} {nz:.6f}\n")
            else:
                f.write(item[1])

    print(f"OBJ fixed: rotated Y-up→Z-up, scaled to {target_height_mm:.0f}mm, centered on XY, bottom at Z=0")
    print(f"Output: {os.path.abspath(output_path)}")

fix_obj_for_printing(obj_path, target_height_mm=75.0)
print(f"\nModel ready for printing: {os.path.abspath(obj_path)}")

Parameters:

• target_height_mm: Default 75mm. Adjust based on user's request (e.g. "print at 15cm" → 150.0).
• The function rotates in-place by default (overwrites the original OBJ).

Opening OBJ in Slicer Software

When the user specifies a slicer (e.g. Bambu Studio, OrcaSlicer, Creality Print, PrusaSlicer, Cura), use the following cross-platform pattern to open the downloaded OBJ file directly:

• macOS: subprocess.run(["open", "-a", "<AppName>", obj_path])
  • The OS resolves the app location automatically. Use the app display name, e.g. "BambuStudio", "OrcaSlicer", "PrusaSlicer".
• Windows / Linux: shutil.which("<binary_name>") to find the executable in PATH, then subprocess.Popen([exe, obj_path]).
  • If not found in PATH, print the file path and instruct the user to open it manually.

If the user does NOT specify a slicer, simply print the OBJ file path and instruct them to open it in their preferred slicer: File → Import / Open → select the .obj file.

Common slicers for reference: Bambu Studio, OrcaSlicer, Creality Print, PrusaSlicer, Cura — but accept any slicer the user names.

Printability Checklist (Manual Review)

Note: Automated printability analysis API is coming soon. For now, manually review the checklist below before printing.

Recommendations: Import into your slicer to check for mesh errors. Use the slicer's built-in repair tool if needed. Consider hollowing figurines to save material.

Key Rules for Print Workflow

• Always download OBJ format for slicer compatibility (3MF not yet available from API)
• If the user specifies a slicer, try to open the OBJ file directly using the cross-platform pattern above
• If the user does NOT specify a slicer, print the file path and guide them to import manually: File → Import / Open → select .obj file
• After opening in slicer, remind user to check print settings (layer height, infill, supports)
• If OBJ is not available: Download GLB and guide user to import manually

Multi-Color Printing (Manual Guidance)

Note: Automated multi-color processing API is coming soon. For now, follow the manual approach below.

1. Use the Retexture API (10 credits) to apply distinct color regions to your model
2. Download the model as OBJ
3. In your slicer's color painting tool, assign filament colors to different regions
4. Slice and print with your multi-color setup (e.g., Bambu Lab AMS, Prusa MMU)

For resin printing, consider painting the model after printing for best color results.

Coming Soon

The following features will be integrated into this skill as their APIs launch:

• Printability Analysis & Fix API — Automated mesh analysis and repair (non-manifold edges, thin walls, floating parts)
• Multi-Color Processing API — Automated color segmentation and filament assignment for AMS/MMU printers

Additional Resources

For the complete API endpoint reference, read reference.md.