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Decimation on imported STL file

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  • Decimation on imported STL file

    Hi. I use 3DZephyr Lite for reverse engineering. I have a STL file that was generated using a laser scanner but the point count is 10,151,037. I would like to reduce that to make the file more manageable in CAD software. After I imported the file into 3DZephyr I tried just using Decimation on the mesh, and it didnt seem to do anything. The points and triangles stayed the same. I created a dense point cloud from the mesh and tried to use decimation on that and it worked, but I have no idea how to create a mesh from the dense point cloud or export the dense point cloud to an STL. Any suggestions?

  • #2
    Hi hammerpe33 - Welcome to the forum!

    STL files are more of a finishing format and don't play nicely with all decimation tools. For example, if you try decimate your STL in Meshlab using the standard Quadric Edge Collapse Decimation filter you will see that lots of little triangle holes will appear in the mesh.

    The reason STL files are a bit of a pain to edit is that they lack certain useful information that can be found in other formats such as .OBJ or .E57 If the laser scanner can output other formats, they may be preferable.

    Sidenote: You can't create a mesh if your dense point cloud is considered 'unstructured'

    The 'make structured' option is enabled when:
    - The center of the scan is in the scan file
    - The bubble view images/information are in the scan file
    - Some photos already in the workspace, for example, from photogrammetry.

    Because your STL file lacks a scan origin or bubble view images, you need to import your STL into a Zephyr workspace that already has photos that can be used to structure the imported file. Once structured, you can convert to dense, and mesh, however note the mesh will be influenced by the photos used for structuring.


    Simpler method: Try importing your STL into Autodesk Meshmixer, select the whole thing and use the Reduce tool to lower the triangle count of your STL. Meshmixer is great for handling STL files that need adjustment prior to print and can do things other programs simply can't! (+ It's free )

    - I avoid STL as much as possible because it's such a hassle to process in my usual workflows.


    • #3
      cam3d Thanks! I tried using meshmixer but there are too many triangles for it to handle the file. The issue right now is that I can usually reduce the scan size in the laser scanner software (GOM Inspect). However they are having some bug in their software licensing and I can t run it until they fix it. Solidworks 2020 does have a decimate feature. I ran it last night but it looks like it will take 7 hours to do a 40% reduction!


      • #4
        hammerpe33 - If you're still having trouble I can try decimating the file for you. You can send a direct download link to