Method for drawing an antiprism with equilateral sides
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http://en.wikipedia.org/wiki/Square_antiprism
I can easily create a version of this by rotating the top face of a cube by 45° and tweaking a few lines.
However the resulting triangles are not equilateral, which is what I'm after.Any ideas?
Thanks*PS
Anyone know a way to construct polygons in SketchUp starting only with their "Nets".
Without knowing the specific folding angle I haven't been able to do this precisely.
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Try this
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seven decimals of °
That is precision
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I think this is a way to do it without calculations, but because sketchup arcs are polygons, its impossible to do a perfectly accurate projection.
I used a default arc (12 sides), if you did one with (say) 256 sides, you could get closer. -
I didn't do calculations either [except for the angle that I added]...
You'll need a Circle with 1000 sides and then just draw/group/copy/rotate stuff... see the 'Steps' illustration...
[I removed the illustration here in favor the the 'steps' set - see the next few posts along...] -
Thanks for the detailed reply Tig.
Unfortunately I'm having trouble figuring out the proper sequence of steps to follow your instructions.
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Hey what happened to all those steps you wrote out Tig?
Anyway I guess the circle approximation is the best we can do...
Thanks everyone
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Here's an improved version of the Steps
It works for any size 'cube'... -
TIG - This Is Google
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Much easier
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Thanks Tig. You're a genius.
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woops!
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@sketchup_roolz said:
Not that anyone cares anymore but here's a my proper 2D method...
http://img573.imageshack.us/img573/272/68861221.pngI fixed your faulty link...
An interesting alternative approach...
I am thinking how it might get converted to an 'algorithm'...
Which must be possible as it involves 45/30/15 degree triangles with known side length...
Sleeping on it now... -
Not that anyone cares anymore but here's a my proper 2D method...
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Very clever Jeff.
Much appreciation for all the hard work here.
I don't really have a practical need to get this level of precision/accuracy but problems like this totally consume me.
I figured the faster I could figure it out it the sooner I could move on to more important things! (or not)SketchUp is an amazing piece of software and maybe one day I'll have a more concrete use for it.
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Why anybody save the SKP file "save as SU6"?
Like this anybody can reload easily any file! -
PS :How many triangles must have the polyedra?
On the first post there are 8 on "the plan"
On the Xray Tig volume there are 7 !
@unknownuser said:
Won't the file lose some of its v7, and v8 features. Did v6 have "dynamic components", etc.?
there are rarelly dynamic component in "hard geometry" like in this post or exotic functions
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@unknownuser said:
Why anybody save the SKP file "save as SU6"?
Like this anybody can reload easily any file!
Won't the file lose some of its v7, and v8 features. Did v6 have "dynamic components", etc.?
Btw, am I sticking my foot in my mouth? I didn't read all of the posts.
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@unknownuser said:
Why anybody save the SKP file "save as SU6"?
Like this anybody can reload easily any file!oops, i try to remember to do this prior to uploading at scf but i just forget sometimes
i added a v6 file to my earlier post -
???????????
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