Polyhedra

Table of contents

Polyhedra Shapes
Further Reading
- Intermediate
- Advanced

Polyhedra Shapes

There are fifteen polyhedra that can be created simply by setting its type number from 0 to 14, and one, the icosphere that is created by name to which more variations can be applied. However there are plenty more to choose from, just follow the instructions under Custom Polyhedra.

Polyhedron

Example :

var octahedron = BABYLON.MeshBuilder.CreatePolyhedron("oct", {type: 1, size: 3}, scene);

Properties, all optional :

property	value	default value
type	(number) polyhedron type in the range [0,14]	0
size	(number) polyhedron size	1
sizeX	(number) X polyhedron size, overwrites the size property	1
sizeY	(number) Y polyhedron size, overwrites the size property	1
sizeZ	(number) Z polyhedron size, overwrites the size property	1
custom	(polygonObjectReference) a polyhedron object, overwrites the type property	null
faceColors	(Color4[]) array of Color4, one per face	Color4(1, 1, 1, 1) for each side
faceUV	(Vector4[]) array of Vector4, one per face	UVs(0, 0, 1, 1) for each side
flat	(boolean) if false, a polyhedron has a single global face, faceUV and faceColors are ignored	true
updatable	(boolean) true if the mesh is updatable	false
sideOrientation	(number) side orientation	DEFAULTSIDE

To understand how to set faceUV or faceColors, please read this http://doc.babylonjs.com/tutorials/CreateBox_Per_Face_Textures_And_Colors taking into account the right number of faces of your polyhedron, instead of only 6 for a box.

Provided Polyhedron Types :

type	name	side number
0	Tetrahedron	4
1	Octahedron	8
2	Dodecahedron	12
3	Icosahedron	20
4	Rhombicuboctahedron	26
5	Triangular Prism	5
6	Pentagonal Prism	7
7	Hexagonal Prism	8
8	Square Pyramid (J1)	5
9	Pentagonal Pyramid (J2)	6
10	Triangular Dipyramid (J12)	6
11	Pentagonal Dipyramid (J13)	10
12	Elongated Square Dipyramid (J15)	12
13	Elongated Pentagonal Dipyramid (J16)	15
14	Elongated Pentagonal Cupola (J20)	22

Custom Polyhedra

If you need to use a custom polyhedron visit http://www.babylonjs-playground.com/#21QRSK#1 -

) : minimize the code editor with the button "EDITOR-" and note the polyhedron names under the mouse pointer. The data for each name can be found in the polyhedra.js file here https://github.com/BabylonJS/Extensions/tree/master/Polyhedron Find the name and copy/paste the wanted polyhedron object in your code like this :

var heptagonalPrism = { "name":"Heptagonal Prism", "category":["Prism"], "vertex":[[0,0,1.090071],[0.796065,0,0.7446715],[-0.1498633,0.7818315,0.7446715],[-0.7396399,-0.2943675,0.7446715],[0.6462017,0.7818315,0.3992718],[1.049102,-0.2943675,-0.03143449],[-0.8895032,0.487464,0.3992718],[-0.8658909,-0.6614378,-0.03143449],[0.8992386,0.487464,-0.3768342],[0.5685687,-0.6614378,-0.6538232],[-1.015754,0.1203937,-0.3768342],[-0.2836832,-0.8247995,-0.6538232],[0.4187054,0.1203937,-0.9992228],[-0.4335465,-0.042968,-0.9992228]],
"face":[[0,1,4,2],[0,2,6,3],[1,5,8,4],[3,6,10,7],[5,9,12,8],[7,10,13,11],[9,11,13,12],[0,3,7,11,9,5,1],[2,4,8,12,13,10,6]]};

var mesh = BABYLON.MeshBuilder.CreatePolyhdron("h", {custom: heptagonalPrism}, scene);

IcoSphere

This a sphere based upon an icosahedron with 20 triangular faces which can be subdivided.

var icosphere = BABYLON.MeshBuilder.CreateIcoSphere("ico", {radius: 5, radiusY: 8, subdivisions: 6}, scene);

Properties, all optional :

property	value	default value
radius	(number) radius	1
radiusX	(number) the X radius, overwrites the radius value	radius
radiusY	(Vector3) the Y radius, overwrites the radius value	radius
radiusZ	(number) the Z radius, overwrites the radius value	radius
subdivisions	(number) the number of subdivisions	4
flat	(boolean) if true, the mesh faces have their own normals	true
updatable	(boolean) true if the mesh is updatable	false
sideOrientation	(number) side orientation	DEFAULTSIDE

An example of an IcoSphere: http://www.babylonjs-playground.com/#24DUYD#1 -

and one with animation: http://www.babylonjs-playground.com/#E3TVT#1 -

Updatable

Where a polyhedral shape has an updatable parameter in its options it means that it is possible to alter the data associated with each vertex of the mesh and so alter the shape of the mesh. For more information see Updating Vertices

intermediate