So I have some lovely JSON exported from Blender using three.js' addon. Works great.
I want to grab colours from each of the materials that the geometry has been exported with and change their material types to "point."
This again works fine according to my console output of the model.material array before and after my .forEach.
Unfortunately, nothing is displayed, as though no material has been applied whatsoever.
As per the inline comment below, a single colour material does work, as do the original materials loaded from the JSON.
var loader = new THREE.JSONLoader();
var model = loader.parse(json from elsewhere);
var mesh;
var pointMats = [];
model.materials.forEach(function(j) {
var color = new THREE.Color(j.color.r, j.color.g, j.color.b);
var specular = new THREE.Color(j.specular.r, j.specular.g, j.specular.b);
var newPointsMat = new THREE.PointsMaterial({
name: j.name,
color: color,
lights: true,
size: 1
});
pointMats.push(newPointsMat);
});
// var pointsMat = new THREE.PointsMaterial( {
// color: 0xffffff,
// size: 0.01
// }); // this works fine and is applied to all the meshes in my scene
mesh = new THREE.Points(model.geometry, pointMats);
scene.add(mesh);
Of course, no errors are given in the console. Probably because there isn't an error to be displayed.
Thanks for your time
THREE.Points accepts a single instance of Material and can't handle an array of them on a single mesh.
I'm a beginner using three.js and I am trying to have two materials defined on one single object, and alternate between the two using a visibilty flag, but with no success.
Is there another way, or can this be done?
var materials = [
new THREE.MeshPhongMaterial( { color: 0x00ff00,visible:true, shininess: 1 } ),
new THREE.MeshPhongMaterial( { color: 0xff0000,visible:false, shininess: 1 } )
];
obj= THREE.SceneUtils.createMultiMaterialObject( geometry, materials );
scene.add( obj);
scene.traverse(function (node){
if(node instanceof THREE.Mesh) {
node.visible =!node.visible;
}
});
I will entually aplly this to all objects in the scene that's why I'm using the scene.traverse
It looks like you're trying to apply visibility to the materials, yet you're checking the meshes during your traverse. Remove the visibility: true/false from your material definitions, and add the following line:
obj= THREE.SceneUtils.createMultiMaterialObject( geometry, materials );
obj.children[1].visible = false; // add this line
scene.add( obj);
This will apply visibility = false to the second mesh created by createMultiMaterialObject. Your traverse will then correctly flip the visibility of the meshes.
As you get to know THREE.js better, you'll want to look into THREE.MultiMaterial and geometry groups for applying multiple materials to a single mesh.
I'm trying to define a model of the human body in THREE.js using the classes THREE.Bone, THREE.Skeleton and THREE.SkinnedMesh.
I defined a custom skeleton structure made of 12 body parts, each of which is a THREE.Bone instance, and used the .add() method to define parent / child relationships among them. Finally, I created a standard THREE.Object3D as the body root that is parent of the full skeleton.
Posting only part of the structure for conciseness:
// create person object
var body_root = new THREE.Object3D()
// create torso
var torso = new THREE.Bone();
torso.id = 1;
torso.name = "torso";
x_t = 0;
y_t = 0;
z_t = 0;
torso.position.set(x_t,y_t,z_t);
x_alpha = 0 * Math.PI;
y_alpha = 0 * Math.PI;
z_alpha = 0 * Math.PI;
torso.rotation.set(x_alpha,y_alpha,z_alpha);
// create right arm
var right_arm = new THREE.Bone();
right_arm.id = 2;
right_arm.name = "right_arm";
x_t = -TORSO_WIDTH / 2;
y_t = TORSO_HEIGHT;
z_t = 0;
right_arm.position.set(x_t,y_t,z_t);
x_alpha = 0 * Math.PI;
y_alpha = 0 * Math.PI;
z_alpha = 0 * Math.PI;
right_arm.rotation.set(x_alpha,y_alpha,z_alpha);
// add right_arm as child of torso
torso.add( right_arm );
This works just fine, and after loading the page I can access the model and traverse it correctly through the console.
However, when I try to render the skeleton in the scene things get tricky.
1. How can I add a THREE.SkinnedMesh for a custom skeleton structure?
In the documentation (check source code) a CylinderGeometry and a SkinnedMesh are created for all the bones jointly
var geometry = new THREE.CylinderGeometry( 5, 5, 5, 5, 15, 5, 30 );
var mesh = THREE.SkinnedMesh( geometry, material );
and then the bone structure is binded:
// See example from THREE.Skeleton for the armSkeleton
var rootBone = armSkeleton.bones[ 0 ];
mesh.add( rootBone );
// Bind the skeleton to the mesh
mesh.bind( armSkeleton );
This works perfectly for the simple example in the documentation (5 bones each one parent of the next one), but how can I adapt this example to a more complex structure in which some bones have multiple children? And how can I implement bones with different geometry? For instance I would like to implement joints like shoulder and elbow with a sphere for which I can only change rotation and body parts like arm and forearm with cylinders having different base radius.
Is it possible to define a SkinnedMesh for each joint independently and for a more complex structure than the one in the example? If so how do you link them all together?
2. Can I add a THREE.SkeletonHelper to the scene without defining a skinned mesh but using only the bones?
Since I don't know the answer to question 1 I decided to simply try to render the skeleton structure. This is done in other examples (such as this one) by creating a THREE.SkeletonHelper instance and adding that to the scene.
I tried passing the body_root variable (instead of the SkinnedMesh) to the constructor and the helper is created, but not rendered.
helper = new THREE.SkeletonHelper( body_root );
helper.material.linewidth = 3;
scene.add( helper );
In order to visualize the helper it needs to be binded to a mesh, even if the mesh is not added directly to the scene, i.e. adding the line mesh.bind(armSkeleton) visualizes the skeleton helper.
Is this possible at all to visualize the skeleton helper without defining a mesh? If so how?
NOTE on question 2:
I believe this should be possible, since the THREE.SkeletonHelper class defines internally its own geometry and material, so it should be possible to render it without needing the mesh of the skeleton:
THREE.SkeletonHelper = function ( object ) {
this.bones = this.getBoneList( object );
var geometry = new THREE.Geometry();
for ( var i = 0; i < this.bones.length; i ++ ) {
var bone = this.bones[ i ];
if ( bone.parent instanceof THREE.Bone ) {
geometry.vertices.push( new THREE.Vector3() );
geometry.vertices.push( new THREE.Vector3() );
geometry.colors.push( new THREE.Color( 0, 0, 1 ) );
geometry.colors.push( new THREE.Color( 0, 1, 0 ) );
}
}
geometry.dynamic = true;
var material = new THREE.LineBasicMaterial( { vertexColors: THREE.VertexColors, depthTest: false, depthWrite: false, transparent: true } );
THREE.LineSegments.call( this, geometry, material );
this.root = object;
this.matrix = object.matrixWorld;
this.matrixAutoUpdate = false;
this.update();
};
Here I bumped to the problem since I need to merge two geometries (or meshes) to one. Using the earlier versions of three.js there was a nice function:
THREE.GeometryUtils.merge(pendulum, ball);
However, it is not on the new version anymore.
I tried to merge pendulum and ball with the following code:
ball is a mesh.
var ballGeo = new THREE.SphereGeometry(24,35,35);
var ballMat = new THREE.MeshPhongMaterial({color: 0xF7FE2E});
var ball = new THREE.Mesh(ballGeo, ballMat);
ball.position.set(0,0,0);
var pendulum = new THREE.CylinderGeometry(1, 1, 20, 16);
ball.updateMatrix();
pendulum.merge(ball.geometry, ball.matrix);
scene.add(pendulum);
After all, I got the following error:
THREE.Object3D.add: object not an instance of THREE.Object3D. THREE.CylinderGeometry {uuid: "688B0EB1-70F7-4C51-86DB-5B1B90A8A24C", name: "", type: "CylinderGeometry", vertices: Array[1332], colors: Array[0]…}THREE.error # three_r71.js:35THREE.Object3D.add # three_r71.js:7770(anonymous function) # pendulum.js:20
To explain Darius' answer more clearly (as I struggled with it, while trying to update a version of Mr Doob's procedural city to work with the Face3 boxes):
Essentially you are merging all of your Meshes into a single Geometry. So, if you, for instance, want to merge a box and sphere:
var box = new THREE.BoxGeometry(1, 1, 1);
var sphere = new THREE.SphereGeometry(.65, 32, 32);
...into a single geometry:
var singleGeometry = new THREE.Geometry();
...you would create a Mesh for each geometry:
var boxMesh = new THREE.Mesh(box);
var sphereMesh = new THREE.Mesh(sphere);
...then call the merge method of the single geometry for each, passing the geometry and matrix of each into the method:
boxMesh.updateMatrix(); // as needed
singleGeometry.merge(boxMesh.geometry, boxMesh.matrix);
sphereMesh.updateMatrix(); // as needed
singleGeometry.merge(sphereMesh.geometry, sphereMesh.matrix);
Once merged, create a mesh from the single geometry and add to the scene:
var material = new THREE.MeshPhongMaterial({color: 0xFF0000});
var mesh = new THREE.Mesh(singleGeometry, material);
scene.add(mesh);
A working example:
<!DOCTYPE html>
<script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/r77/three.js"></script>
<!-- OrbitControls.js is not versioned and may stop working with r77 -->
<script src='http://threejs.org/examples/js/controls/OrbitControls.js'></script>
<body style='margin: 0px; background-color: #bbbbbb; overflow: hidden;'>
<script>
// init renderer
var renderer = new THREE.WebGLRenderer();
renderer.setSize(window.innerWidth, window.innerHeight);
document.body.appendChild(renderer.domElement);
// init scene and camera
var scene = new THREE.Scene();
var camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 0.01, 3000);
camera.position.z = 5;
var controls = new THREE.OrbitControls(camera)
// our code
var box = new THREE.BoxGeometry(1, 1, 1);
var sphere = new THREE.SphereGeometry(.65, 32, 32);
var singleGeometry = new THREE.Geometry();
var boxMesh = new THREE.Mesh(box);
var sphereMesh = new THREE.Mesh(sphere);
boxMesh.updateMatrix(); // as needed
singleGeometry.merge(boxMesh.geometry, boxMesh.matrix);
sphereMesh.updateMatrix(); // as needed
singleGeometry.merge(sphereMesh.geometry, sphereMesh.matrix);
var material = new THREE.MeshPhongMaterial({color: 0xFF0000});
var mesh = new THREE.Mesh(singleGeometry, material);
scene.add(mesh);
// a light
var light = new THREE.HemisphereLight(0xfffff0, 0x101020, 1.25);
light.position.set(0.75, 1, 0.25);
scene.add(light);
// render
requestAnimationFrame(function animate(){
requestAnimationFrame(animate);
renderer.render(scene, camera);
})
</script>
</body>
At least, that's how I am interpreting things; apologies to anyone if I have something wrong, as I am no where close to being a three.js expert (currently learning). I just had the "bad luck" to try my hand at customizing Mr. Doob's procedural city code, when the latest version breaks things (the merge stuff being one of them, the fact that three.js no longer uses quads for cube -ahem- box geometry the other - which has led to all kinds of fun getting the shading and such to work properly again).
Finally, I found a possible solution. I am posting since it could be useful for somebody else while I wasted a lot of hours. The tricky thing is about manipulating the concept of meshes and geometries:
var ballGeo = new THREE.SphereGeometry(10,35,35);
var material = new THREE.MeshPhongMaterial({color: 0xF7FE2E});
var ball = new THREE.Mesh(ballGeo, material);
var pendulumGeo = new THREE.CylinderGeometry(1, 1, 50, 16);
ball.updateMatrix();
pendulumGeo.merge(ball.geometry, ball.matrix);
var pendulum = new THREE.Mesh(pendulumGeo, material);
scene.add(pendulum);
The error message is right. CylinderGeometry is not an Object3D. Mesh is. A Mesh is constructed from a Geometry and a Material. A Mesh can be added to the scene, while a Geometry cannot.
In the newest versions of three.js, Geometry has two merge methods: merge and mergeMesh.
merge takes a mandatory argument geometry, and two optional arguments matrix and materialIndexOffset.
geom.mergeMesh(mesh) is basically a shorthand for geom.merge(mesh.geometry, mesh.matrix), as used in other answers. ('geom' and 'mesh' being arbitrary names for a Geometry and a Mesh, respectively.) The Material of the Mesh is ignored.
This is my ultimate compact version in four (or five) lines (as long as material is defined somewhere else) making use of mergeMesh:
var geom = new THREE.Geometry();
geom.mergeMesh(new THREE.Mesh(new THREE.BoxGeometry(2,20,2)));
geom.mergeMesh(new THREE.Mesh(new THREE.BoxGeometry(5,5,5)));
geom.mergeVertices(); // optional
scene.add(new THREE.Mesh(geom, material));
Edit: added optional extra line to remove duplicate vertices, which should help performance.
Edit 2: I'm using the newest version, 94.
The answers and code that I've seen posted here do not work because the second argument of the merge method is an integer, not a matrix. As far as I can tell, the merge method is not really functioning in a useful way. Therefore, I used the following approach to make a simple rocket with a nose cone.
import * as BufferGeometryUtils from '../three.js/examples/jsm/utils/BufferGeometryUtils.js'
lengthSegments = 2
radius = 5
radialSegments = 32
const bodyLength = dParamWithUnits['launchVehicleBodyLength'].value
const noseConeLength = dParamWithUnits['launchVehicleNoseConeLength'].value
// Create the vehicle's body
const launchVehicleBodyGeometry = new THREE.CylinderGeometry(radius, radius, bodyLength, radialSegments, lengthSegments, false)
launchVehicleBodyGeometry.name = "body"
// Create the nose cone
const launchVehicleNoseConeGeometry = new THREE.CylinderGeometry(0, radius, noseConeLength, radialSegments, lengthSegments, false)
launchVehicleNoseConeGeometry.name = "noseCone"
launchVehicleNoseConeGeometry.translate(0, (bodyLength+noseConeLength)/2, 0)
// Merge the nosecone into the body
const launchVehicleGeometry = BufferGeometryUtils.mergeBufferGeometries([launchVehicleBodyGeometry, launchVehicleNoseConeGeometry])
// Rotate the vehicle to horizontal
launchVehicleGeometry.rotateX(-Math.PI/2)
const launchVehicleMaterial = new THREE.MeshPhongMaterial( {color: 0x7f3f00})
const launchVehicleMesh = new THREE.Mesh(launchVehicleGeometry, launchVehicleMaterial)
I'm having trouble applying a texture to an object I exported. My code looks like this:
var loader = new THREE.ObjectLoader();
var texture = THREE.ImageUtils.loadTexture('models/mountain/mountain.png');
loader.load("models/mountain/mountain.json", function (obj) {
var material = new THREE.MeshPhongMaterial({
map: texture
});
mesh = new THREE.Mesh( obj, material );
scene.add( mesh );
});
Just adding the obj to the scene works fine, but when I have to set a mesh and texture I get an error. What should the correct syntax be?
your problem may be that the "obj" returned by the ObjectLoader is actually just a Object3D. The objects containing the actual geometry and materials are children of this "obj".
So to change material you need to:
for(var i = 0; i < obj.children.length; i++)
{
obj.children[i].material = new THREE.PhongMaterial...
}
Also, please look into the MTL loader. OBJ/MTL loader is the usual way to use textured OBJs, as seen in the example: http://threejs.org/examples/#webgl_loader_obj_mtl