Geometry, Materials and Mesh in Three.js Question

0
votes

Currently working with Three.js.

What I have:

As shown in the figure and code below i have a for loop that create a specific object on random position in the scene.

Figure: Demo Image Code:

//Create Objects
var geometry = new THREE.CylinderBufferGeometry( 0, 10, 30, 4, 1 );
var material = new THREE.MeshPhongMaterial( { color: 0xffffff, flatShading: true } );

for(var i=0; i<100; i++) {

    var mesh = new THREE.Mesh( geometry, material );
    mesh.position.x = getRandomInt(-500,500);
    mesh.position.y = getRandomInt(10, 100);
    mesh.position.z = getRandomInt(-500,500);
    mesh.updateMatrix();
    mesh.matrixAutoUpdate = false;
    scene_Main.add( mesh );
}

My Question:

How to create random objects of different material and geometry in a for loop?

Can i use the idea of creating an array that holds the specific geometry/material and if so how to store this in an array and how to use it?

array idea: 

var geometryList = [cube, pyramid, sphere, donut, ...];
var materialList = [ .. what posibilities I have here? .. ];

for(var i=0; i<100; i++) {
    var mesh = new THREE.Mesh( geometryList[random[n]], materialList[random[n]] );
    ....    
}
2
javascriptthree.jsgeometrymesh
check the documentation and examples of THREE.js for materials supported, there are Simple materials, Illumination-specific materials (like Phong) and so on.. Search around - Nikos M.
thanks ill look into it - Loizos Vasileiou

2 Answers

1
votes

You can do anything you want really. You just have to populate your materialList[] One way

for(var i=0; i<100; i++) {
    color = new THREE.Color( 0xffffff );
    color.setHex( Math.random() * 0xffffff );
    materialList.push(new THREE.MeshBasicMaterial({ color: color }));
}

of cource your random[n] function must return something between [0-99]

0
votes
var materialList = [];


    for(var i=0; i<150; i++) {

        //Prepare different material for each object
        var color = new THREE.Color( 0xffffff );
        color.setHex( Math.random() * 0xffffff );
        materialList.push(new THREE.MeshBasicMaterial({ color: color }));

        //Prepare diferent sizes for the objects
        var geometrySize_2 = getRandomInt(5,30);

        //Create  50 Pyramids
        if(i <= 50){

            var geometry1 = new THREE.CylinderBufferGeometry( 0, 10, 30, 4, 1 );

            var mesh = new THREE.Mesh( geometry1, materialList[i] );
            mesh.position.x = getRandomInt(-500,500);
            mesh.position.y = getRandomInt(10, 150);
            mesh.position.z = getRandomInt(-500,500);
            mesh.updateMatrix();
            mesh.matrixAutoUpdate = false;
            scene_Main.add( mesh );
        }
        //Create 50 Cubes
        else if(i <= 100 && i>= 50){

            var geometry2 = new THREE.BoxGeometry(geometrySize_2,geometrySize_2,geometrySize_2);

            var mesh = new THREE.Mesh( geometry2, materialList[i] );
            mesh.position.x = getRandomInt(-500,500);
            mesh.position.y = getRandomInt(10, 150);
            mesh.position.z = getRandomInt(-500,500);
            mesh.updateMatrix();
            mesh.matrixAutoUpdate = false;
            scene_Main.add( mesh );
        }
        //Create 100 Spheres
        else if(i <= 150 && i>= 50){

            var geometry3 = new THREE.SphereGeometry( 5, 32, 32 );

            var mesh = new THREE.Mesh( geometry3, materialList[i] );
            mesh.position.x = getRandomInt(-500,500);
            mesh.position.y = getRandomInt(10, 150);
            mesh.position.z = getRandomInt(-500,500);
            mesh.updateMatrix();
            mesh.matrixAutoUpdate = false;
            scene_Main.add( mesh );
        }
    }

enter image description here