Sierpinski 3D Arrowhead Curve

Sierpinski 3D Arrowhead Curve
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2019-04-13 18:51
① This example demonstrates the Sierpinski 3D arrowhead curve, a fractal curve generated by recursive subdivision of tetrahedra in three-dimensional space, showcasing the fascinating application of fractal geometry to solid shapes. ② Core mathematical concepts include fractal geometry, recursive iteration, tetrahedron structure, midpoint subdivision, geometric transformations (rotation), and construction of space curves. ③ Construction highlights: using GeoGebra commands such as Rotate, Tetrahedron, Midpoint, PolyLine, Centroid, Line, and Intersect, along with multiple points (A, B, C, D, E, etc.) and faces (faceABC, faceAA'B, etc.), the curve is built through iterative steps; objects include tetrahedra, edges, midpoints, and polylines. ④ Suitable for high school and above students or math enthusiasts, this example is ideal for exploring fractal geometry, recursive constructions in 3D space, and as an extension activity in computer-assisted geometry teaching.

GeoGebra Commands & Parameters

  1. Rotate(A, (2 * π / 3)) → A'
  2. Point(Circle[Midpoint[A, A'], (Distance[A, A'] * sqrt(3) / 2), Segment[A, A']]) → B
  3. Tetrahedron(A, A', B) → a, C, edgeBC, edgeA'C, faceAA'B, faceABC, faceAA'C, faceA'BC, edgeAB, edgeAA'_1, edgeA'B, edgeAC
  4. Midpoint(edgeA'B) → D
  5. Midpoint(edgeA'C) → E
  6. Midpoint(edgeAA'_1) → F
  7. Midpoint(edgeAB) → G
  8. Midpoint(edgeAC) → H
  9. Midpoint(edgeBC) → I
  10. PolyLine(B, I, H, F, A') → f
  11. Centroid(faceAA'C) → J
  12. Line(B, J) → g
  13. Intersect(g, zAxis) → K
  14. Line(A, K) → h
  15. Line(A', K) → i
  16. Rotate(PolyLine[Dilate[B, 0.5, B], Dilate[I, 0.5, B], Dilate[H, 0.5, B], Dilate[F, 0.5, B], Dilate[A', 0.5, B]], (-2 * π / 3), Line[B, K]) → j
  17. Rotate(PolyLine[Dilate[B, 0.5, A], Dilate[I, 0.5, A], Dilate[H, 0.5, A], Dilate[F, 0.5, A], Dilate[A', 0.5, A]], (2 * π / 3), Line[A, K]) → k
  18. Rotate(PolyLine[Dilate[B, 0.5, C], Dilate[I, 0.5, C], Dilate[H, 0.5, C], Dilate[F, 0.5, C], Dilate[A', 0.5, C]], (2 * π / 3), Line[C, K]) → l
  19. Rotate(PolyLine[Dilate[B, 0.5, A'], Dilate[I, 0.5, A'], Dilate[H, 0.5, A'], Dilate[F, 0.5, A'], Dilate[A', 0.5, A']], (-2 * π / 3), Line[A', K]) → m
  20. Point(Circle[Midpoint[A, A'], (Distance[A, A'] * sqrt(3) / 2), Segment[A, A']]) → L
  21. Tetrahedron(A, A', L) → b, M, edgeLM, edgeA'M, faceAA'L, faceALM, faceAA'M, faceA'LM, edgeAL, edgeAA', edgeA'L, edgeAM

AI Drawing Prompt Reference

Draw a 3D Sierpinski arrowhead curve generated by recursively subdividing tetrahedra, showcasing fractal geometry in solid shapes. Start by rotating a point, then find midpoints and connect lines to construct tetrahedra, extracting edges and faces. Use midpoints and segments to create polylines, then rotate and scale these polylines, combining them with lines and points to form a complex fractal curve structure.
The prompt above was compiled from the original drawing commands and is for reference only.