Formula
( ( ( x + 0 ) 2 + ( y + 0 ) 2 + ( z + 0 ) 2 − 1.6900000000000002 ) 2 − 3.106870229007634 ( 1 − ( z + 0 ) − 1.4142135623730951 ( x + 0 ) ) ( 1 − ( z + 0 ) + 1.4142135623730951 ( x + 0 ) ) ( 1 + z + 0 + 1.4142135623730951 ( y + 0 ) ) ( 1 + z + 0 − 1.4142135623730951 ( y + 0 ) ) ) ( ( ( x + 1 ) 2 + ( y + 1 ) 2 + ( z + 1 ) 2 − 6.760000000000001 ) 2 − 3.106870229007634 ( 2 − ( z + 1 ) − 1.4142135623730951 ( x + 1 ) ) ( 2 − ( z + 1 ) + 1.4142135623730951 ( x + 1 ) ) ( 2 + z + 1 + 1.4142135623730951 ( y + 1 ) ) ( 2 + z + 1 − 1.4142135623730951 ( y + 1 ) ) − 2 ( ( ( x + 0.5 ) 2 + ( y + 0.5 ) 2 + ( z + 0.5 ) 2 − 3.8025 ) 2 − 3.106870229007634 ( 1.5 − ( z + 0.5 ) − 1.4142135623730951 ( x + 0.5 ) ) ( 1.5 − ( z + 0.5 ) + 1.4142135623730951 ( x + 0.5 ) ) ( 1.5 + z + 0.5 + 1.4142135623730951 ( y + 0.5 ) ) ( 1.5 + z + 0.5 − 1.4142135623730951 ( y + 0.5 ) ) ) + 2 ( ( ( x − 0.5 ) 2 + ( y − 0.5 ) 2 + ( z − 0.5 ) 2 − 0.42250000000000004 ) 2 − 3.106870229007634 ( 0.5 − ( z − 0.5 ) − 1.4142135623730951 ( x − 0.5 ) ) ( 0.5 − ( z − 0.5 ) + 1.4142135623730951 ( x − 0.5 ) ) ( 0.5 + z − 0.5 + 1.4142135623730951 ( y − 0.5 ) ) ( 0.5 + z − 0.5 − 1.4142135623730951 ( y − 0.5 ) ) ) − ( ( ( x − 1 ) 2 + ( y − 1 ) 2 + ( z − 1 ) 2 − 0 ) 2 − 3.106870229007634 ( 0 − ( z − 1 ) − 1.4142135623730951 ( x − 1 ) ) ( 0 − ( z − 1 ) + 1.4142135623730951 ( x − 1 ) ) ( 0 + z − 1 + 1.4142135623730951 ( y − 1 ) ) ( 0 + z − 1 − 1.4142135623730951 ( y − 1 ) ) ) ) 0.25 6 ( ( ( x + 1 ) 2 + ( y + 1 ) 2 + ( z + 1 ) 2 − 6.760000000000001 ) 2 − 3.106870229007634 ( 2 − ( z + 1 ) − 1.4142135623730951 ( x + 1 ) ) ( 2 − ( z + 1 ) + 1.4142135623730951 ( x + 1 ) ) ( 2 + z + 1 + 1.4142135623730951 ( y + 1 ) ) ( 2 + z + 1 − 1.4142135623730951 ( y + 1 ) ) − 2 ( ( ( x + 0.5 ) 2 + ( y + 0.5 ) 2 + ( z + 0.5 ) 2 − 3.8025 ) 2 − 3.106870229007634 ( 1.5 − ( z + 0.5 ) − 1.4142135623730951 ( x + 0.5 ) ) ( 1.5 − ( z + 0.5 ) + 1.4142135623730951 ( x + 0.5 ) ) ( 1.5 + z + 0.5 + 1.4142135623730951 ( y + 0.5 ) ) ( 1.5 + z + 0.5 − 1.4142135623730951 ( y + 0.5 ) ) ) + 2 ( ( ( x − 0.5 ) 2 + ( y − 0.5 ) 2 + ( z − 0.5 ) 2 − 0.42250000000000004 ) 2 − 3.106870229007634 ( 0.5 − ( z − 0.5 ) − 1.4142135623730951 ( x − 0.5 ) ) ( 0.5 − ( z − 0.5 ) + 1.4142135623730951 ( x − 0.5 ) ) ( 0.5 + z − 0.5 + 1.4142135623730951 ( y − 0.5 ) ) ( 0.5 + z − 0.5 − 1.4142135623730951 ( y − 0.5 ) ) ) − ( ( ( x − 1 ) 2 + ( y − 1 ) 2 + ( z − 1 ) 2 − 0 ) 2 − 3.106870229007634 ( 0 − ( z − 1 ) − 1.4142135623730951 ( x − 1 ) ) ( 0 − ( z − 1 ) + 1.4142135623730951 ( x − 1 ) ) ( 0 + z − 1 + 1.4142135623730951 ( y − 1 ) ) ( 0 + z − 1 − 1.4142135623730951 ( y − 1 ) ) ) ) 0.25 6 − 14.143580916030535 ( − ( ( ( x + 1 ) 2 + ( y + 1 ) 2 + ( z + 1 ) 2 − 6.760000000000001 ) 2 − 3.106870229007634 ( 2 − ( z + 1 ) − 1.4142135623730951 ( x + 1 ) ) ( 2 − ( z + 1 ) + 1.4142135623730951 ( x + 1 ) ) ( 2 + z + 1 + 1.4142135623730951 ( y + 1 ) ) ( 2 + z + 1 − 1.4142135623730951 ( y + 1 ) ) ) + 8 ( ( ( x + 0.5 ) 2 + ( y + 0.5 ) 2 + ( z + 0.5 ) 2 − 3.8025 ) 2 − 3.106870229007634 ( 1.5 − ( z + 0.5 ) − 1.4142135623730951 ( x + 0.5 ) ) ( 1.5 − ( z + 0.5 ) + 1.4142135623730951 ( x + 0.5 ) ) ( 1.5 + z + 0.5 + 1.4142135623730951 ( y + 0.5 ) ) ( 1.5 + z + 0.5 − 1.4142135623730951 ( y + 0.5 ) ) ) − 8 ( ( ( x − 0.5 ) 2 + ( y − 0.5 ) 2 + ( z − 0.5 ) 2 − 0.42250000000000004 ) 2 − 3.106870229007634 ( 0.5 − ( z − 0.5 ) − 1.4142135623730951 ( x − 0.5 ) ) ( 0.5 − ( z − 0.5 ) + 1.4142135623730951 ( x − 0.5 ) ) ( 0.5 + z − 0.5 + 1.4142135623730951 ( y − 0.5 ) ) ( 0.5 + z − 0.5 − 1.4142135623730951 ( y − 0.5 ) ) ) + ( ( x − 1 ) 2 + ( y − 1 ) 2 + ( z − 1 ) 2 − 0 ) 2 − 3.106870229007634 ( 0 − ( z − 1 ) − 1.4142135623730951 ( x − 1 ) ) ( 0 − ( z − 1 ) + 1.4142135623730951 ( x − 1 ) ) ( 0 + z − 1 + 1.4142135623730951 ( y − 1 ) ) ( 0 + z − 1 − 1.4142135623730951 ( y − 1 ) ) ) 6 ( − ( ( ( x + 1 ) 2 + ( y + 1 ) 2 + ( z + 1 ) 2 − 6.760000000000001 ) 2 − 3.106870229007634 ( 2 − ( z + 1 ) − 1.4142135623730951 ( x + 1 ) ) ( 2 − ( z + 1 ) + 1.4142135623730951 ( x + 1 ) ) ( 2 + z + 1 + 1.4142135623730951 ( y + 1 ) ) ( 2 + z + 1 − 1.4142135623730951 ( y + 1 ) ) ) + 8 ( ( ( x + 0.5 ) 2 + ( y + 0.5 ) 2 + ( z + 0.5 ) 2 − 3.8025 ) 2 − 3.106870229007634 ( 1.5 − ( z + 0.5 ) − 1.4142135623730951 ( x + 0.5 ) ) ( 1.5 − ( z + 0.5 ) + 1.4142135623730951 ( x + 0.5 ) ) ( 1.5 + z + 0.5 + 1.4142135623730951 ( y + 0.5 ) ) ( 1.5 + z + 0.5 − 1.4142135623730951 ( y + 0.5 ) ) ) − 8 ( ( ( x − 0.5 ) 2 + ( y − 0.5 ) 2 + ( z − 0.5 ) 2 − 0.42250000000000004 ) 2 − 3.106870229007634 ( 0.5 − ( z − 0.5 ) − 1.4142135623730951 ( x − 0.5 ) ) ( 0.5 − ( z − 0.5 ) + 1.4142135623730951 ( x − 0.5 ) ) ( 0.5 + z − 0.5 + 1.4142135623730951 ( y − 0.5 ) ) ( 0.5 + z − 0.5 − 1.4142135623730951 ( y − 0.5 ) ) ) + ( ( x − 1 ) 2 + ( y − 1 ) 2 + ( z − 1 ) 2 − 0 ) 2 − 3.106870229007634 ( 0 − ( z − 1 ) − 1.4142135623730951 ( x − 1 ) ) ( 0 − ( z − 1 ) + 1.4142135623730951 ( x − 1 ) ) ( 0 + z − 1 + 1.4142135623730951 ( y − 1 ) ) ( 0 + z − 1 − 1.4142135623730951 ( y − 1 ) ) ) 6 = 0 \frac{\frac{\frac{\frac{\left(\left(\left(x + 0\right)^{2} + \left(y + 0\right)^{2} + \left(z + 0\right)^{2} - 1.6900000000000002\right)^{2} - 3.106870229007634 \left(1 - \left(z + 0\right) - 1.4142135623730951 \left(x + 0\right)\right) \left(1 - \left(z + 0\right) + 1.4142135623730951 \left(x + 0\right)\right) \left(1 + z + 0 + 1.4142135623730951 \left(y + 0\right)\right) \left(1 + z + 0 - 1.4142135623730951 \left(y + 0\right)\right)\right) \left(\left(\left(x + 1\right)^{2} + \left(y + 1\right)^{2} + \left(z + 1\right)^{2} - 6.760000000000001\right)^{2} - 3.106870229007634 \left(2 - \left(z + 1\right) - 1.4142135623730951 \left(x + 1\right)\right) \left(2 - \left(z + 1\right) + 1.4142135623730951 \left(x + 1\right)\right) \left(2 + z + 1 + 1.4142135623730951 \left(y + 1\right)\right) \left(2 + z + 1 - 1.4142135623730951 \left(y + 1\right)\right) - 2 \left(\left(\left(x + 0.5\right)^{2} + \left(y + 0.5\right)^{2} + \left(z + 0.5\right)^{2} - 3.8025\right)^{2} - 3.106870229007634 \left(1.5 - \left(z + 0.5\right) - 1.4142135623730951 \left(x + 0.5\right)\right) \left(1.5 - \left(z + 0.5\right) + 1.4142135623730951 \left(x + 0.5\right)\right) \left(1.5 + z + 0.5 + 1.4142135623730951 \left(y + 0.5\right)\right) \left(1.5 + z + 0.5 - 1.4142135623730951 \left(y + 0.5\right)\right)\right) + 2 \left(\left(\left(x - 0.5\right)^{2} + \left(y - 0.5\right)^{2} + \left(z - 0.5\right)^{2} - 0.42250000000000004\right)^{2} - 3.106870229007634 \left(0.5 - \left(z - 0.5\right) - 1.4142135623730951 \left(x - 0.5\right)\right) \left(0.5 - \left(z - 0.5\right) + 1.4142135623730951 \left(x - 0.5\right)\right) \left(0.5 + z - 0.5 + 1.4142135623730951 \left(y - 0.5\right)\right) \left(0.5 + z - 0.5 - 1.4142135623730951 \left(y - 0.5\right)\right)\right) - \left(\left(\left(x - 1\right)^{2} + \left(y - 1\right)^{2} + \left(z - 1\right)^{2} - 0\right)^{2} - 3.106870229007634 \left(0 - \left(z - 1\right) - 1.4142135623730951 \left(x - 1\right)\right) \left(0 - \left(z - 1\right) + 1.4142135623730951 \left(x - 1\right)\right) \left(0 + z - 1 + 1.4142135623730951 \left(y - 1\right)\right) \left(0 + z - 1 - 1.4142135623730951 \left(y - 1\right)\right)\right)\right)}{0.25}}{6} \left(\left(\left(x + 1\right)^{2} + \left(y + 1\right)^{2} + \left(z + 1\right)^{2} - 6.760000000000001\right)^{2} - 3.106870229007634 \left(2 - \left(z + 1\right) - 1.4142135623730951 \left(x + 1\right)\right) \left(2 - \left(z + 1\right) + 1.4142135623730951 \left(x + 1\right)\right) \left(2 + z + 1 + 1.4142135623730951 \left(y + 1\right)\right) \left(2 + z + 1 - 1.4142135623730951 \left(y + 1\right)\right) - 2 \left(\left(\left(x + 0.5\right)^{2} + \left(y + 0.5\right)^{2} + \left(z + 0.5\right)^{2} - 3.8025\right)^{2} - 3.106870229007634 \left(1.5 - \left(z + 0.5\right) - 1.4142135623730951 \left(x + 0.5\right)\right) \left(1.5 - \left(z + 0.5\right) + 1.4142135623730951 \left(x + 0.5\right)\right) \left(1.5 + z + 0.5 + 1.4142135623730951 \left(y + 0.5\right)\right) \left(1.5 + z + 0.5 - 1.4142135623730951 \left(y + 0.5\right)\right)\right) + 2 \left(\left(\left(x - 0.5\right)^{2} + \left(y - 0.5\right)^{2} + \left(z - 0.5\right)^{2} - 0.42250000000000004\right)^{2} - 3.106870229007634 \left(0.5 - \left(z - 0.5\right) - 1.4142135623730951 \left(x - 0.5\right)\right) \left(0.5 - \left(z - 0.5\right) + 1.4142135623730951 \left(x - 0.5\right)\right) \left(0.5 + z - 0.5 + 1.4142135623730951 \left(y - 0.5\right)\right) \left(0.5 + z - 0.5 - 1.4142135623730951 \left(y - 0.5\right)\right)\right) - \left(\left(\left(x - 1\right)^{2} + \left(y - 1\right)^{2} + \left(z - 1\right)^{2} - 0\right)^{2} - 3.106870229007634 \left(0 - \left(z - 1\right) - 1.4142135623730951 \left(x - 1\right)\right) \left(0 - \left(z - 1\right) + 1.4142135623730951 \left(x - 1\right)\right) \left(0 + z - 1 + 1.4142135623730951 \left(y - 1\right)\right) \left(0 + z - 1 - 1.4142135623730951 \left(y - 1\right)\right)\right)\right)}{0.25}}{6} - \frac{\frac{14.143580916030535 \left(-\left(\left(\left(x + 1\right)^{2} + \left(y + 1\right)^{2} + \left(z + 1\right)^{2} - 6.760000000000001\right)^{2} - 3.106870229007634 \left(2 - \left(z + 1\right) - 1.4142135623730951 \left(x + 1\right)\right) \left(2 - \left(z + 1\right) + 1.4142135623730951 \left(x + 1\right)\right) \left(2 + z + 1 + 1.4142135623730951 \left(y + 1\right)\right) \left(2 + z + 1 - 1.4142135623730951 \left(y + 1\right)\right)\right) + 8 \left(\left(\left(x + 0.5\right)^{2} + \left(y + 0.5\right)^{2} + \left(z + 0.5\right)^{2} - 3.8025\right)^{2} - 3.106870229007634 \left(1.5 - \left(z + 0.5\right) - 1.4142135623730951 \left(x + 0.5\right)\right) \left(1.5 - \left(z + 0.5\right) + 1.4142135623730951 \left(x + 0.5\right)\right) \left(1.5 + z + 0.5 + 1.4142135623730951 \left(y + 0.5\right)\right) \left(1.5 + z + 0.5 - 1.4142135623730951 \left(y + 0.5\right)\right)\right) - 8 \left(\left(\left(x - 0.5\right)^{2} + \left(y - 0.5\right)^{2} + \left(z - 0.5\right)^{2} - 0.42250000000000004\right)^{2} - 3.106870229007634 \left(0.5 - \left(z - 0.5\right) - 1.4142135623730951 \left(x - 0.5\right)\right) \left(0.5 - \left(z - 0.5\right) + 1.4142135623730951 \left(x - 0.5\right)\right) \left(0.5 + z - 0.5 + 1.4142135623730951 \left(y - 0.5\right)\right) \left(0.5 + z - 0.5 - 1.4142135623730951 \left(y - 0.5\right)\right)\right) + \left(\left(x - 1\right)^{2} + \left(y - 1\right)^{2} + \left(z - 1\right)^{2} - 0\right)^{2} - 3.106870229007634 \left(0 - \left(z - 1\right) - 1.4142135623730951 \left(x - 1\right)\right) \left(0 - \left(z - 1\right) + 1.4142135623730951 \left(x - 1\right)\right) \left(0 + z - 1 + 1.4142135623730951 \left(y - 1\right)\right) \left(0 + z - 1 - 1.4142135623730951 \left(y - 1\right)\right)\right)}{6} \left(-\left(\left(\left(x + 1\right)^{2} + \left(y + 1\right)^{2} + \left(z + 1\right)^{2} - 6.760000000000001\right)^{2} - 3.106870229007634 \left(2 - \left(z + 1\right) - 1.4142135623730951 \left(x + 1\right)\right) \left(2 - \left(z + 1\right) + 1.4142135623730951 \left(x + 1\right)\right) \left(2 + z + 1 + 1.4142135623730951 \left(y + 1\right)\right) \left(2 + z + 1 - 1.4142135623730951 \left(y + 1\right)\right)\right) + 8 \left(\left(\left(x + 0.5\right)^{2} + \left(y + 0.5\right)^{2} + \left(z + 0.5\right)^{2} - 3.8025\right)^{2} - 3.106870229007634 \left(1.5 - \left(z + 0.5\right) - 1.4142135623730951 \left(x + 0.5\right)\right) \left(1.5 - \left(z + 0.5\right) + 1.4142135623730951 \left(x + 0.5\right)\right) \left(1.5 + z + 0.5 + 1.4142135623730951 \left(y + 0.5\right)\right) \left(1.5 + z + 0.5 - 1.4142135623730951 \left(y + 0.5\right)\right)\right) - 8 \left(\left(\left(x - 0.5\right)^{2} + \left(y - 0.5\right)^{2} + \left(z - 0.5\right)^{2} - 0.42250000000000004\right)^{2} - 3.106870229007634 \left(0.5 - \left(z - 0.5\right) - 1.4142135623730951 \left(x - 0.5\right)\right) \left(0.5 - \left(z - 0.5\right) + 1.4142135623730951 \left(x - 0.5\right)\right) \left(0.5 + z - 0.5 + 1.4142135623730951 \left(y - 0.5\right)\right) \left(0.5 + z - 0.5 - 1.4142135623730951 \left(y - 0.5\right)\right)\right) + \left(\left(x - 1\right)^{2} + \left(y - 1\right)^{2} + \left(z - 1\right)^{2} - 0\right)^{2} - 3.106870229007634 \left(0 - \left(z - 1\right) - 1.4142135623730951 \left(x - 1\right)\right) \left(0 - \left(z - 1\right) + 1.4142135623730951 \left(x - 1\right)\right) \left(0 + z - 1 + 1.4142135623730951 \left(y - 1\right)\right) \left(0 + z - 1 - 1.4142135623730951 \left(y - 1\right)\right)\right)}{6} = 0
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Properties
Family algebraic
Given by an implicit equation
Curvature no condition imposed
Periodicity not periodic
Ends 0
Embedding immersed with singularities
Fidelity exact
Exactness elementary
Definition
Humbert's 1896 sextic, tied to abelian functions of genus 3 and built from a Kummer quartic: it inherits the Kummer surface's 16 nodes and adds a triple point at (1:1:1:1).
Sources
Closed form reproduced numerically against the shipped implementation (math_art/surfaces/algebraic.py) over 240 sample points: matches oracle x 1 over 240 points (worst 9.3e-10).
E. W. Weisstein, "Peano Surface", "Chair", "Crossed Trough", "Handkerchief Surface", "Hunt's Surface", "Kiss Surface", "Menn's Surface", "Miter Surface", "Nordstrand's Weird Surface", "Tooth Surface", MathWorld -- A Wolfram Web Resource, mathworld.wolfram.com.
T. Nordstrand, "Weird Cube" and the tooth/pillow object, per the MathWorld pages (Nordstrand 1997).
G. Peano's 1899 counterexample; cf. the MathWorld page's history of the criterion it defeated.
O. Labs, 'Advent calendar 2002, No. 18', The Algebraic Surface Homepage, algebraicsurface.net (Wayback rescue, captures to 2017-10-01; local mirror: algsurf/book/.../ch036_no_18.md).
G. Humbert, 'Sur une surface du sixieme ordre liee aux fonctions abeliennes de genre 3', J. de Mathem., 2e serie, t. III (1896); collected papers vol. 2, p. 269-296 (the page's reference). Description and equation communicated to O. Labs by W. Barth.