I'm trying to simplify an 3D Model (.STL file) that is loaded using STLLoader and the Three.js function SimplifyModifier to reduce vertices and simplify the model.
I have a function called loadMesh that loads the file and return an Three.js mesh that renders on a Scene:
/**
* Method to load the mesh model from .stl or .3mf file and return Mesh ThreeJS object
* #param {*} part Part or model of a part, on form of a .stl or .3mf file
* #param {*} color Color of the mesh material. Default = #0096d6
* #returns Mesh from ThreeJS
*/
static loadMesh(part, color = '#0096d6') {
if (!FileUtil.existsPath(part.path)) return null;
const loader = (Loader, encoding) => new Loader().parse(FileUtil.readFile(part.path, encoding));
let mesh = null;
const material = new THREE.MeshStandardMaterial({ color, flatShading: true });
const ext = FileUtil.getExtName(part.path, true).toLowerCase();
if (ext == 'stl') {
const geometry = loader(STLLoader, 'binary');
// Make an instance of SimplifyModifier
const modifier = new SimplifyModifier();
// Create Mesh wit geometry and material already defined
mesh = new THREE.Mesh(geometry, material);
// Number of vertices to remove from part
const count = Math.floor( mesh.geometry.attributes.position.count * 0.1 );
console.log(count);
// Now modify the geometry of our mesh to optimize number of polygons
mesh.geometry = modifier.modify( mesh.geometry, count );
} else if (ext == '3mf') {
mesh = loader(ThreeMFLoader, 'buffer');
for (const [index, buildItem] of Object.entries(mesh.children)) {
(function updateMaterial(children) {
for (const child of children) {
if (child.children?.length > 0) {
updateMaterial(child.children);
} else {
child.index = String(index);
child.material = material.clone();
}
}
})(buildItem.children);
}
if (part.buildItemIndex != 'all') {
mesh = mesh.children[+part.buildItemIndex];
mesh.position.set(0, 0, 0);
}
}
mesh.part = part;
MeshUtil.resetOrigin(mesh);
return mesh;
}
Currently the app supports two 3d files extensions: .STL and .3MF, that's why you can use that the function checks the extension and its executes based on that. But for the moment im trying to simplify an STL model, so the important thing here is happening inside the STL if condition:
const geometry = loader(STLLoader, 'binary');
// Make an instance of SimplifyModifier
const modifier = new SimplifyModifier();
// Create Mesh wit geometry and material already defined
mesh = new THREE.Mesh(geometry, material);
// Number of vertices to remove from part
const count = Math.floor( mesh.geometry.attributes.position.count * 0.1 );
//
console.log(count);
// Now modify the geometry of our mesh to optimize number of polygons
mesh.geometry = modifier.modify( mesh.geometry, count );
When I try to render the model on another component using
// mesh is the returned mesh from the above function
scene.add(mesh);
I get the next error on console:
Notes
Already tried to change count of vertices to remove and there is no difference.
For better reference, there are the properties of the geometry object that im trying to simplify:
The purpose of this is because in some cases the app can receive large files and it crashes when trying to render on Scene.
Also, don't know if there is any problem that is BufferGeometry, and if its the case, how can I solved that?
This may seem like a very trivial problem but I can't find a solution to this. I've added an object to the scene using OBJLoader as seen below. How can I remove it from the scene? I've tried using code to clear scene.children, but this doesn't remove my "flower.obj"
const mloader = new THREE.OBJLoader();
mloader.load
(
'models/flower.obj', function(object)
{
object.scale.x=1
object.translateZ(2);
scene.add(object);
}
);
You need to save a reference to the loaded object so you can subsequently call scene.remove() when you're ready to get rid of it.
var flower;
const mloader = new THREE.OBJLoader();
mloader.load('models/flower.obj',
function(object) {
flower = object;
flower.scale.x=1
flower.translateZ(2);
scene.add(flower);
}
);
function removeFlower() {
scene.remove(flower);
}
I have several models in Clara.io, according to their help if you export selection, then it will be file for JSONLoader, and if you export full scene it will be file for ObjectLoader. However non of export function working with JSONLoader (https://forum.clara.io/t/export-to-three-js-json-export-all-and-export-selected-both-export-scene-object/3709).
In my app I need only geometry from model to build Points object. So I'm looking for either methods to convert loaded object to Mesh, or some king of geometry subtraction from object itself. In helps and examples(both three and clara) I see only one action with loaded object - scene.add(object).
import THREE from 'three/build/three.module';
import {Scene,PerspectiveCamera,Fog,WebGLRenderer,ObjectLoader,Geometry} from 'three/build/three.module';
....
var loader = new ObjectLoader();
loader.load( 'assets/models/rabbit.json', function ( object ) {
//I don't need to add object here but this is the only thing that works
//scene.add(object);
//I need to do something like this
geometry2 = new Geometry();
geometry2.vertices = object.geometry.vertices; // ???
particles = new Points( geometry2, new PointsMaterial( { color: 0xff0000, size:5 } ) );
scene.add(particles)
});
So clara.io seems to export single object in scene. So the way to extract mesh from it is something like:
loader.load( 'assets/models/rabbit.json', function ( object ) {
//I don't need to add object here but this is the only thing that works
//scene.add(object);
//I need to do something like this
geometry2 = new Geometry();
geometry2.vertices = object.children[0].geometry.vertices;
//object.children[0] - the first mesh in exported object
particles = new Points( geometry2, new PointsMaterial( { color: 0xff0000, size:5 } ) );
scene.add(particles)
});
I am using ThreeJS to load OBJs into a webpage, which I have done succesfully, but now I want to add buttons to my page that will swap out the displayed OBJ file for a different one. I have attempted to name the object when loading it:
object.name = "selectedObject";
so that I can remove it from the scene when the new button is clicked
scene.remove( selectedObject );
and attach the new object:
scene.add(newobject);
But I am getting lost in how to implement this into the general code/what the correct syntax would be.
Here's the code for loading the model:
var objectloading = 'obj/male02/new.obj';
var loader = new THREE.OBJLoader( manager );
loader.load( objectloading, function ( object ) {
object.traverse( function ( child ) {
if ( child instanceof THREE.Mesh ) {
child.material.map = texture;
}
} );
object.position.y = -30;
scene.add( object );
}, onProgress, onError );
Any help is apreciated, thanks!
Well there's many ways to go about it. What it comes down to is that your code needs to account for what has been loaded. You can traverse a scene, but capturing and listing your obj files into specific lists on your own is much cleaner, especially later when implementing things like raycasting.
I would write some functions, perhaps even a class if I planned on supporting other mesh types in the future and wanted a single interface. Importantly, you do not pass the mesh name as the parameter to scene.add and scene.remove, you pass a reference to the actual object. Three.js does this so that it can nullify the parent and call the object "removed" dispatch event in the Three.js library.
So for example purposes, one way is to store your objects in a hash, and use the url to the mesh as the parameter for adding and removal.
var meshes = {};
addObj = function(url){
var objectloading = url;
var loader = new THREE.OBJLoader( manager );
loader.load( objectloading, function ( object ) {
object.traverse( function ( child ) {
if ( child instanceof THREE.Mesh ) {
child.material.map = texture;
}
} );
object.position.y = -30;
meshes[url] = object;
scene.add(object);
}, onProgress, onError );
}
removeObj = function(url){
scene.remove(meshes[url]);
delete meshes[url];
}
for example, toggle between two models,
in a button click:
removeObj('obj/male02/old.obj');
addObj('obj/male02/new.obj');
and then in another button click:
removeObj('obj/male02/new.obj');
addObj('obj/male02/old.obj');
Although any String can be used for member names in "meshes," using urls could become problematic if the application grows and the url is actually a service uri utilizing a POST request, then you'll need another layer of references, possibly and usually using the UUID give to each object added to Three.js.
I'm using ThreeJS to develop a web application that displays a list of entities, each with corresponding "View" and "Hide" button; e.g. entityName View Hide. When user clicks View button, following function is called and entity drawn on screen successfully.
function loadOBJFile(objFile){
/* material of OBJ model */
var OBJMaterial = new THREE.MeshPhongMaterial({color: 0x8888ff});
var loader = new THREE.OBJLoader();
loader.load(objFile, function (object){
object.traverse (function (child){
if (child instanceof THREE.Mesh) {
child.material = OBJMaterial;
}
});
object.position.y = 0.1;
scene.add(object);
});
}
function addEntity(object) {
loadOBJFile(object.name);
}
And on clicking Hide button, following function is called:
function removeEntity(object){
scene.remove(object.name);
}
The problem is, entity is not removed from screen once loaded when Hide button is clicked. What can I do to make Hide button to work?
I did small experiment. I added scene.remove(object.name); right after scene.add(object); within addEntity function and as result, when "View" button clicked, no entity drawn (as expected) meaning that scene.remove(object.name); worked just fine within addEntity. But still I'm unable to figure out how to use it in removeEntity(object).
Also, I checked contents of scene.children and it shows: [object Object],[object Object],[object Object],[object Object],[object Object],[object Object]
Complete code: http://devplace.in/~harman/model_display1.php.html
Please ask, if more detail is needed. I tested with rev-59-dev and rev-60 of ThreeJS.
Thanks. :)
I think seeing your usage for addEntity and removeEntity code would be helpful, but my first thought is are you actually setting the object.name? Try in your loader just before scene.add(object); something like this:
object.name = "test_name";
scene.add(object);
What might be happening is the default "name" for an Object3D is "", so when you then call your removeEntity function it fails due to the scene objects name being ""
Also, I notice you pass in object.name to your loader? Is this where your storing the URL to the resource? If so, I would recommend using the Object3D's built in .userData method to store that information and keep the name field for scene identification purposes.
Edit: Response to newly added Code
First thing to note is it's not a great idea to have "/" in your object name, it seems to work fine but you never know if some algorithm will decide to escape that string and break your project.
Second item is now that I've seen your code, its actually straight forward whats going on. Your delete function is trying to delete by name, you need an Object3D to delete. Try this:
function removeEntity(object) {
var selectedObject = scene.getObjectByName(object.name);
scene.remove( selectedObject );
animate();
}
Here you see I lookup your Object3D in the Three.js Scene by passing in your object tag's name attribute.
clearScene: function() {
var objsToRemove = _.rest(scene.children, 1);
_.each(objsToRemove, function( object ) {
scene.remove(object);
});
},
this uses undescore.js to iterrate over all children (except the first) in a scene (it's part of code I use to clear a scene). just make sure you render the scene at least once after deleting, because otherwise the canvas does not change! There is no need for a "special" obj flag or anything like this.
Also you don't delete the object by name, just by the object itself, so calling
scene.remove(object);
instead of scene.remove(object.name);
can be enough
PS: _.each is a function of underscore.js
I came in late but after reading the answers more clarification needs to be said.
The remove function you wrote
function removeEntity(object) {
// scene.remove(); it expects as a parameter a THREE.Object3D and not a string
scene.remove(object.name); // you are giving it a string => it will not remove the object
}
A good practice to remove 3D objects from Three.js scenes
function removeObject3D(object3D) {
if (!(object3D instanceof THREE.Object3D)) return false;
// for better memory management and performance
if (object3D.geometry) object3D.geometry.dispose();
if (object3D.material) {
if (object3D.material instanceof Array) {
// for better memory management and performance
object3D.material.forEach(material => material.dispose());
} else {
// for better memory management and performance
object3D.material.dispose();
}
}
object3D.removeFromParent(); // the parent might be the scene or another Object3D, but it is sure to be removed this way
return true;
}
If your element is not directly on you scene go back to Parent to remove it
function removeEntity(object) {
var selectedObject = scene.getObjectByName(object.name);
selectedObject.parent.remove( selectedObject );
}
THIS WORKS GREAT - I tested it
so, please SET NAME for every object
give the name to the object upon creation
mesh.name = 'nameMeshObject';
and use this if you have to delete an object
delete3DOBJ('nameMeshObject');
function delete3DOBJ(objName){
var selectedObject = scene.getObjectByName(objName);
scene.remove( selectedObject );
animate();
}
open a new scene , add object
delete an object and create new
I started to save this as a function, and call it as needed for whatever reactions require it:
function Remove(){
while(scene.children.length > 0){
scene.remove(scene.children[0]);
}
}
Now you can call the Remove(); function where appropriate.
When you use : scene.remove(object);
The object is removed from the scene, but the collision with it is still enabled !
To remove also the collsion with the object, you can use that (for an array) :
objectsArray.splice(i, 1);
Example :
for (var i = 0; i < objectsArray.length; i++) {
//::: each object ::://
var object = objectsArray[i];
//::: remove all objects from the scene ::://
scene.remove(object);
//::: remove all objects from the array ::://
objectsArray.splice(i, 1);
}
I improve Ibrahim code for removeObject3D, added some checks for geometry or material
removeObject3D(object) {
if (!(object instanceof THREE.Object3D)) return false;
// for better memory management and performance
if (object.geometry) {
object.geometry.dispose();
}
if (object.material) {
if (object.material instanceof Array) {
// for better memory management and performance
object.material.forEach(material => material.dispose());
} else {
// for better memory management and performance
object.material.dispose();
}
}
if (object.parent) {
object.parent.remove(object);
}
// the parent might be the scene or another Object3D, but it is sure to be removed this way
return true;
}
this example might give you a different approach . I was trying to implement a similar feature in my project also with scene.remove(mesh). However disposal of geometry and material attributes of mesh worked for me!
source
Use
scene.remove(Object)
The object you want to remove from the scene
I had The same problem like you have. I try this code and it works just fine:
When you create your object put this object.is_ob = true
function loadOBJFile(objFile){
/* material of OBJ model */
var OBJMaterial = new THREE.MeshPhongMaterial({color: 0x8888ff});
var loader = new THREE.OBJLoader();
loader.load(objFile, function (object){
object.traverse (function (child){
if (child instanceof THREE.Mesh) {
child.material = OBJMaterial;
}
});
object.position.y = 0.1;
// add this code
object.is_ob = true;
scene.add(object);
});
}
function addEntity(object) {
loadOBJFile(object.name);
}
And then then you delete your object try this code:
function removeEntity(object){
var obj, i;
for ( i = scene.children.length - 1; i >= 0 ; i -- ) {
obj = scene.children[ i ];
if ( obj.is_ob) {
scene.remove(obj);
}
}
}
Try that and tell me if that works, it seems that three js doesn't recognize the object after added to the scene. But with this trick it works.
You can use this
function removeEntity(object) {
var scene = document.querySelectorAll("scene"); //clear the objects from the scene
for (var i = 0; i < scene.length; i++) { //loop through to get all object in the scene
var scene =document.getElementById("scene");
scene.removeChild(scene.childNodes[0]); //remove all specified objects
}