I am trying to create dice of different shapes - tetrahedron, cube and octahedron. I was able to get which side landed on top in a cube using the quaternion and figuring out certain patterns like this, this too although isnt perfect - if (Math.abs(body.quaternion.y) < 0.00001) { lastRoll +=…

I would go the way, where I take the index of the side, whose normal’s dot product , in world coordinates, is closer to 1, against the up-vector (0, 1, 0). Dot product in the docs: https://threejs.org/docs/index.html#api/en/math/Vector3.dot

An alternative is to cast a ray from the center upwards and the intersection will return which face is just above the center.

AFAIK, die’s material needs to have side: THREE.DoubleSide for that case. But yes, it’s an option too :slight_smile: Maybe, to cast a ray from atop (put it high enough) towards the center of a die. And also, in case of a cube, there is a very slight chance, when a ray goes in between two faces, th…

@prisoner849 , how can i get the individual side’s normal ?

The normal of any face, that belongs to the side, is the normal of the side :thinking:

@prisoner849 , but how can I get each face’s normal ?

Any face consists of three vertices. The normal for any of these vertices is the normal of the face :thinking: This works for BoxGeometry and for other geometries, that extended from PolyhedronGeometry.

Yes but how can I get the vertices of the individual faces of a cube made through boxgeometry like this - let g = new THREE.BoxGeometry(2, 2, 2); How can i iterate through the faces of the cube and get the vertices/ normal of each of the 6 faces of this cube to calculate the side of the cube whic…

@prisoner849 , what about for Octahedron and Tetrahedron geometry ? How can i iterate through the faces of these shapes and get the vertices/ normal of each side from these shapes?

How can I get which side landed on top in an octahedron dice?

Questions

prisoner849 March 25, 2024, 7:05am 10

Specifically for BoxGeometry you can iterate through g.attributes.normal, getting data for every fourth vertex.
Some information about BufferGeometry: How ot get vertices, faces, faceVertexUvs from bufferGeometry - #2 by prisoner849

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How can I get which side landed on top in an octahedron dice?

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