Triangulation cylinder with holes

[hofk]

The triangulation of the cylinder with holes is similar to that of the sphere. Triangulation sphere with holes
But with different parameters. For the sphere this variant is also in progress.

Try it out https://hofk.de/main/threejs/Triangulation/TriangulationCylinderWithHoles.html

(UPDATE February 2020: Combination of shapes, see Inner Geometry (Triangulation) )

One variant is integrated in the addon THREEi.
Addon for triangulation of implicit surfaces/ forms with holes

hofk/THREEi.js

Cylinder with holes and edge adaptation for other cylinders.

In order to allow the correct adjustment, d (rough side length of the triangles) must be specified. The radius is then d / Math.sin( Math.PI / (div4 * 4) ) / 2

const g = new THREE.BufferGeometry( );

const parameters =  {

	d: 0.052, // rough side length of the triangles
	div4: 30, // division of the quarter circle
	bottom: -1, 
	div4Btm: 30, // division bottom adaptation, (to quarter, >= div4)
	phiBtm: 1.57, // rotation of adaptive-deformed circle (Bottom)
	top: 1,
	div4Top: 33, // division top adaptation, (to quarter, >= div4)
	phiTop: -0.2, // rotation of adaptive-deformed circle (Top)
	
	holes: [
		// circular (deformed) hole, 3 elements: [ y, phi, div4Hole ], div4Hole <= div4	
		[   0.3,  1.6, 12 ],
		[  -0.4,  3.7, 14 ],
		[  -0.1, -0.9, 18 ],	
		//points hole,: array of points y, phi, ...  (last point is connected to first)
		[ 0.15,0.45, 0.5,0.9, 0.8,0.6, 0.75,-0.2, 0.1,-0.15  ]
	]
	
}

cylinderWithHoles( g, parameters );

edge adaptation:

These cylinders can then be used to realize inner geometry.

The sphere and the torus will soon be added to this.

[prisoner849]

Great work!

[hofk]

From now on you can try out the simple example of the inner geometry here. Take the slider!
InnerGeometryCylinder

---

UPDATE February 2020
see

Inner Geometry (Triangulation)

The triangulation of the different shapes (sphere, cylinder, torus … plane surfaces) uses the same algorithm with only small differences due to the mathematical dependencies. See Triangulation sphere with holes Triangulation cylinder with holes If you want to combine different shapes into an inner geometry, it is better to have only one function. This function then uses the appropriate mathematics for the geometry (normal, surface point …). In addition to the triangulation functions, the c…

[hofk]

The construction was enhanced.

In the basic version, only cylinders in the central position could be adapted again at the cylinder ends.

Now spheres, cylinders or planes can be docked to the cylinder ends.

The connections can also be made excentrically and at any angle to each other.

const parameters = {

	// excenter unit: '%' of the radius, 'd' factor to d, 'v' value
		
	d: 0.14, // rough side length of the triangles
	div4: 17, // division of the quarter circle
	
	geoBtm: 'plane', // 'plane', 'sphere', 'cylinder' solid to be adapted
	bottom:  -4,
	div4Btm: 34, // division bottom adaptation, (to quarter, >= div4)
	phiBtm: 0.77, // rotation of adaptive-deformed circle (Bottom)	
	excBtm: 1.2,
	excUnitBtm: 'v',
	tiltBtm: 0.5, // tilt of bottom adaption ( -PI/2 < tilt < PI/2 )

	geoTop: 'cylinder', //  'plane', 'sphere', 'cylinder' solid to be adapted
	top: 2,
	div4Top: 44, // division top adaptation, (to quarter, >= div4)
	phiTop: 0.77, // rotation of adaptive-deformed circle (Top)
	excTop: 148,
	excUnitTop: '%',
	tiltTop: 0.5, // tilt of top adaption ( -PI/2 < tilt < PI/2 )
	
	holes: [
		
		//  hole to conect a sphere:  [ 'sphere', div4AdpSphere, y, phi, exc, unit ]	
		[ 'sphere', 16, -1.11, 0,  2.686, 'v' ],
		
		// hole to conect a cylinder: [ 'cylinder', div4AdpCylinder, y, phi, exc, unit, tilt, <optional: side> ]
		[ 'cylinder', 8,  -2.2, 1.57, 52.898, '%', -0.22, '+-' ], // side is ignored for connected hole
		
		//points hole,: array of points y, phi, ...  (last point is connected to first)
		[ 0.15,0.45, 0.5,0.9, 0.8,0.6, 0.75,-0.2, 0.1,-0.15  ]
		
	]
 
}

Try here - use the slider.
https://hofk.de/main/threejs/Triangulation/TriangulationCylinderWithHolesEnhanced01.html

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The goal is to combine the design for elementary bodies and surfaces to create more complex inner geometries.

So far only spheres ( Triangulation sphere with holes ) and cylinders are realized. Torus and polygons are still missing.

[hofk]

Has been further developed and integrated, see
Triangulation sphere with holes - #9 by hofk

[hofk]

In former times I always threw away my leg dresses when they had holes in them.
People have been buying jeans like that for a while now - not me!!!
Should a product configurator for hole stockings be created

[makc3d]

oh lol somebody flagged this, apparently they dont like the holes in cylinders. oh well, their loss.

[hofk]

In my clumsiness , did I come across the flag myself on the first viewing with the smartphone? No idea

I like the sock pattern.