# circle tessellation and apothems

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## circle tessellation and apothems

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## Re: circle tessellation and apothems

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## Re: circle tessellation and apothems

 Administrator In reply to this post by Whosawhatsis On Dec 22, 2010, at 20:59 PM, Whosawhatsis wrote: > I was thinking about the problem of making holes in objects (particularly those for 3d printing), and how to keep tessellation from making a screw not fit into a hole due to the difference between the radius and the apothem of a polygon. Good idea! I don't like the idea of using the term 'apothem', as I think that will alienate users more than attracting them. Rather than introducing an extra parameter for the apothem, we could add a boolean parameter which controls how the radius parameter(s) should be interpreted, and name it accordingly. Alternatively, we could add a special variable which toggles this behavior globally (like \$fn, \$fa etc.). What users will perceive is whether the circle approximation is inscribed or circumscribed related to the actual circle (which might be _slightly_ more common terms than apothem ;), so some naming scheme reflecting this would be nice. Ideas? The math is trivial. I would just replace the radius prior to the calculations like this somewhere in primitives.cc: double actual_r = r1 / cos(M_PI / fragments);  -Marius
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## Re: circle tessellation and apothems

 On Sat, Dec 25, 2010 at 4:27 PM, Marius Kintel <[hidden email]> wrote: > Rather than introducing an extra parameter for the apothem, we could add a boolean parameter which controls how the radius parameter(s) should be interpreted, and name it accordingly. In terms most can easily understand, we're talking about whether the radius parameter represents the inner diameter (ID) or outer diameter (OD) of the circle.  Right now, radius represents OD. Perhaps that helps? --tim
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## Re: circle tessellation and apothems

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## Re: circle tessellation and apothems

 Administrator On Dec 26, 2010, at 17:26 PM, Andrew Plumb wrote: > How about calling the parameter "snap" with a range from [0,1]: > I like this approach, although snap sounds a bit "snap to grid" like.  -Marius
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