Editing part sizes of a 3d model - three.js

Question

I want to develop a web app to entering measurements of a man and displaying a 3d model with these measurements. I have chosen three.js to start it. And I downloaded a 3d model named standard-male-figure from clara.io. Here is my code to display human model.
import React, { Component } from "react";
import PropTypes from "prop-types";
import withStyles from "#material-ui/core/styles/withStyles";
import * as THREE from "three-full";
const styles = (/*theme*/) => ({
});
class ThreeDView extends Component {
constructor(props){
super(props);
this.start = this.start.bind(this);
this.stop = this.stop.bind(this);
this.renderScene - this.renderScene.bind(this);
this.animate = this.animate.bind(this);
}
componentDidMount() {
const width = this.mount.clientWidth;
const height = this.mount.clientHeight;
//ADD SCENE
this.scene = new THREE.Scene();
//ADD CAMERA
this.camera = new THREE.PerspectiveCamera(100,1);
this.camera.position.z = 12;
this.camera.position.y = 0;
this.camera.position.x = 0;
//ADD RENDERER
this.renderer = new THREE.WebGLRenderer({ antialias: true });
this.renderer.setClearColor("#f0f0f0");
this.renderer.setSize(width, height);
this.mount.appendChild(this.renderer.domElement);
// MOUSE ROTATION
this.orbit = new THREE.OrbitControls(this.camera,this.renderer.domElement);
this.orbit.update();
//ADD LIGHTS
this.light = new THREE.PointLight(0xffffff,1.3);
this.light.position.z = 10;
this.light.position.y=20;
this.scene.add(this.light);
// ADD MAN FIGURE
const loader = new THREE.ColladaLoader();
loader.load("/models/standard-male-figure.dae",(manFigure)=>{
this.man = manFigure;
this.man.name = "man-figure";
this.man.scene.position.y = -10;
this.scene.add(this.man.scene);
},undefined,()=>alert("Loading failed"));
this.start();
}
componentWillUnmount() {
this.stop();
this.mount.removeChild(this.renderer.domElement);
}
start() {
if (!this.frameId) {
this.frameId = requestAnimationFrame(this.animate);
}
}
stop () {
cancelAnimationFrame(this.frameId);
}
animate () {
this.renderScene();
this.frameId = window.requestAnimationFrame(this.animate);
}
renderScene () {
this.orbit.update();
this.light.position.z = this.camera.position.z;
this.light.position.y=this.camera.position.y+20;
this.light.position.x=this.camera.position.x;
this.renderer.render(this.scene, this.camera);
}
render() {
return (
<div style={{ height: "640px" }} ref={(mount) => { this.mount = mount; }} >
</div>
);
}
}
ThreeDView.propTypes = {
values: PropTypes.object
};
/*
all values in inches
values = {
heightOfHand:10,
, etc..
}
*/
export default withStyles(styles)(ThreeDView);
values is measurements that user is entering. I have no idea about how to start updating 3d model with these measurements. Please give me a starting point or any advise to complete this. Thank You!.

Answer 1

Firstly you can get the current size and scale of your man
const box = new THREE.Box3().setFromObject(this.man)
const currentObjectSize = box.getSize()
const currentObjectScale = this.man.scale
and when an user update the size value (newSize), you can calculate a new scale for you man
const newScale = new THREE.Vector3(
currentObjectScale.x * newSize.x/currentObjectSize.x,
currentObjectScale.y * newSize.y/currentObjectSize.y,
currentObjectScale.z * newSize.z/currentObjectSize.z
)
and update your man with this scale
this.man.scale.set(newScale.x, newScale.y, newScale.z)