Christchurch Technical and 3D Printing Services

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Capturing a Design

When turning an object into an electronic file for 3D printing, there are different methods:

  1. Parametric Modeling:

    • The best starting point is a blueprint drawing, but if that isn’t available, we can make one.

    • Measure the object and all of the fine features in all dimensions

    • Take 6 or more still photographs of an example object to guide the modelling process and copy its shape.

    • Create a parametric model using Fusion 360 design tool. Define “Configuration” parameters.

    • Allows flexible tweaks and modifications.

    • Relatively fast for simpler objects, but time spent increases with complexity.

    • The process can be slow when a large mesh file from Scanning or Photogrammetry is used as the base. Try to reduce the number of mesh triangles below 20,000.

  2. Scanning:

    • Use a scanning tool (e.g., "Mole" scanner) for accurate reproduction.

    • Limited by the size of the object and capability (eg. price) of the scanner device.

    • Captures all of the details, but might not be as precise as required and shapes can be distorted.

    • Time is needed to clean up the image after scanning.

    • Its not the preferred method, but sometimes its the only way.

  3. Photogrammetry:

    • Take many (60+) photos from various angles using a high-resolution camera (e.g., Nikon, Canon or a smartphone) and a fixed focal length lens. Often hundreds of photos may be needed.

    • The resolution of the sensor in a camera is often much higher than an inexpensive scanner.

    • Software aligns the photos and creates a detailed model.

    • More flexible in regards object size than scanning.

    • Captures all of the details and textures.

    • Highly suited to large scale scenes and cars, buildings.

Scanned or photogrammetric files contain many data points, influencing realism. However, dealing with millions of points can be computationally intensive, increasing time spent and therefore modeling costs. Its best to reduce the number of mesh triangles below 20,000. This will help to keep modelling costs within reasonable bounds.

Tradeoff:

  • Parametric Modeling:

    • Time-consuming but precise.

    • Flexible. Detailed dimensions can easily be changed.

  • Scanning or Photogrammetry:

    • Faster, but manipulation may take time.

    • Affected by the number of mesh triangles in the file provided.

    • Decision depends on the required precision and whether modifications are going to be needed.

Considerations:

  • Manipulation Challenges:

    • Large numbers of data points requiring complex mathematical calculations.

    • Time-consuming and can strain computer resources.

  • Decision-Making:

    • Choosing a method depends on factors like precision needed and required modifications.

    • Experience and technical expertise guide the decision-making process.

    • The project budget may also influence the decision.