• bloopernova@programming.dev
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    1 year ago

    I’m not very knowledgeable about 3D printing. Are you saying that the model isn’t a sphere that is then interpreted by a printer to fit its filament size? I guess I assumed models were vectored like SVG image file?

    • ℛ𝒶𝓋ℯ𝓃@pawb.social
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      1 year ago

      Resin printers don’t have a “filament size,” it’s the resolution of the screen that cures an ultra-thin sheet of resin, separates, and repeats until the shape is formed. If the model was spherical, the object would be nearly a perfect sphere by visual inspection. They fed it a faceted, low-poly sphere you could pull off with a fdm printer (filament deposition). As far as detail, FDM = le Potato Cutter, Resin = DaVinci Robotic Surgical System.

    • ubermeisters@lemmy.world
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      1 year ago

      Yes and no. You’ve got a correct notion but it’s one level removed from what I meant.

      When I design a 3d model in CAD software, that software uses a mathematical formula set, to define the model. When I export the model to a mesh, the “rasterization” you mention occurs, removing the parametric/variable nature of my model, in favor of a finite set of triangular faces. This is done because the programs that prepare a mesh for 3d printing, use an internal sense of “mesh volume” to determine negative from positive volumes, so that layer slices can be established.

      What I’m talking about, is the above, combined with the next “reduction of precision”, where certain types of additive manufacturing, have varying levels of resolution in all axis. SLA (reactive resin + masked light) has a very fine feature resolution when compared to FDM (melty plastic shooter, most common in households).

      The resin printed mesh appears to already have been heavily reduced in order to be a highly faceted form. I’m just surprised tonsee someone use SLA on a mesh that is well within the feature size tolerance range for a FDM printer. That’s all. Sometimes people want a faceted look intentionally, for that “low poly” feel akin to Playstation 1 graphics, it could just be that, combined with maybe someone only had SLA available to them.

      FDM can take longer to print, for some meshes/settings, but SLA is a pain in the dick to clean and post-cure (properly), while all the resins are either toxic to us or the earth. And most printer operators are not fastidious about this aspect of printer ownership, partly due to deceptive tactics like some brands hinting at, but not being, safe for the environment.