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+--- Thread: 5-fold symmetry? (/thread-29016.html)
5-fold symmetry? - Peter Blomberg - 2025-08-22
I'm working on the duplo flower with 5 Leaves and Top Stud 84195. I've fixed most of the issues with the original mesh, but...
I don't know if I should submit it as one part or subdivide it into 5 (10) repeatable subparts. One of the challenges is rotation. The original mesh is not aligned with any axis (see top view in picture), so it would be very difficult to create clean symmetrical breaks (normally I'd use the mirroring over an axis). The angle of rotation between parts would be 72 degrees, which would require six decimals in the transformation matrix. Given these challenges, would it be acceptable to "ignore" the 5-fold symmetry and just not subfile at all?
RE: 5-fold symmetry? - Magnus Forsberg - 2025-08-22
Sometimes you need to break the rules.
I would subfile and rotate, and ignore any rotation problem.
RE: 5-fold symmetry? - Philippe Hurbain - 2025-08-22
(Yesterday, 6:34)Magnus Forsberg Wrote: Sometimes you need to break the rules.+1.
I would subfile and rotate, and ignore any rotation problem.
The first thing I would do is to rotate the whole flower (why this weird orientation in the Bi mesh???), isolate and subfile a petal, make the stem and flower heart using primitives, slightly enlarge the petal subpart to make sure it interpenetrate the stem/heart avoiding any gaps when rotated. Then create the flower from the heart+stem and 5 rotated petals, and use isecalc to create the intersection line between the 16-fold symmetry center and 5-fold petals.
Possibly the petal can be further subparted to halves + middle part.
RE: 5-fold symmetry? - Gerald Lasser - 2025-08-22
(Yesterday, 7:06)Philippe Hurbain Wrote: +1.
The first thing I would do is to rotate the whole flower (why this weird orientation in the Bi mesh???), isolate and subfile a petal, make the stem and flower heart using primitives, slightly enlarge the petal subpart to make sure it interpenetrate the stem/heart avoiding any gaps when rotated. Then create the flower from the heart+stem and 5 rotated petals, and use isecalc to create the intersection line between the 16-fold symmetry center and 5-fold petals.
Possibly the petal can be further subparted to halves + middle part.
Yes, the petal itself can be halved!
I did work on this a while ago (1 year) as the mesh is pretty coarse, so I refined the outer a bit, may be you want to take a look
RE: 5-fold symmetry? - Peter Blomberg - 2025-08-22
Thanks for the help with the flower. It's now on the tracker.
What about this one? The top has 4-fold symmetry, but the scalloped sides have 5-fold symmetry.
Am I misremembering or was this part on the tracker some time (year) ago?
RE: 5-fold symmetry? - Philippe Hurbain - 2025-08-23
(10 hours ago)Peter Blomberg Wrote: Thanks for the help with the flower. It's now on the tracker.More questionable indeed. I'd probably make a half petal subpart, assemble them with half middle in a second subpart used twice in the main part.
What about this one? The top has 4-fold symmetry, but the scalloped sides have 5-fold symmetry.
Am I misremembering or was this part on the tracker some time (year) ago?
I don't remember this one on PT, what's the part# btw?