I am trying to change the geometry of some objects in a three.js scene. I have an almost-working piece of code where a mouse click triggers the change, but got the following problem: the (rendered) shape is only changed on the first mouse click, even though the geometry is also successfully modified by each following clicks. Using v66 or v68 of three.js library, if it is relevant.
I read Three.js: Completely change object's Geometry and Updating a geometry inside a mesh does nothing but couldn't get my code to work so far.
Relevant parts of my code:
var count = 0, item, geometry;
var geoms = [new THREE.SphereGeometry(2), new THREE.BoxGeometry(3, 3, 3)];
function init() {
geometry = geoms[count];
item = new THREE.Mesh(geometry, material);
scene.add(item);
}
// Mouse click listener.
function handleClick(event) {
count = 1 - count;
geometry = geoms[count];
item.geometry = geometry;
/* With that next line, on the first click, the sphere
* becomes a cube (as intended), but further clicks don't
* change the view anymore, even though item.geometry is
* modified.
*/
item.geometry.buffersNeedUpdate = true;
/* If I try next line instead, I got the following error:
* "TypeError: l.geometryGroupsList is undefined"
* from three.js.
*/
// item.geometry.verticesNeedUpdate = true;
}
Here is a jsfiddle of a (non-)working example. There is a sphere on screen, a click will make it a cube. Further clicks are supposed to switch between sphere and cube, but nothing change on-screen.
I don't know exactly why this happens. It is unable to update geometry of mesh by a geometry object once used.
.clone() works in this case.
item.geometry.dispose();
item.geometry = geometry.clone();
dispose() previous geometry object to prevent memory leaks.
There would be a better solution.
i found this code to run the fastest:
item.geometry.computeFaceNormals();
item.geometry.computeVertexNormals();
item.geometry.normalsNeedUpdate = true;
item.geometry.verticesNeedUpdate = true;
item.geometry.dynamic = true;
Related
I'm using EdgesGeometry on PlaneGeometry and it seems it creates a larger hitbox in mouse events. This however, isn't evident when using CircleGeometry. I have the following:
createPanel = function(width, height, widthSegments) {
var geometry = new THREE.PlaneBufferGeometry(width, height, widthSegments);
var edges = new THREE.EdgesGeometry( geometry );
var panel = new THREE.LineSegments( edges, new THREE.LineBasicMaterial({
color: 0xffffff }));
return panel;
}
var tile = createPanel(1.45, .6, 1);
Now I'm using a library called RayInput which does all the raycasting for me but imagine I'm just using a normal raycaster for mouse events. Without the edges and using just the plane, the boundaries of collision is accurate.
After adding EdgesGeometry, the vertical hitbox seems to has increased dramatically thus, the object is detected being clicked when I'm not even clicking on it. The horizontal hitbox seems to have increased only slightly. I've never used EdgesGeometry before so anyone have a clue what is going on?
Thanks in advance.
If you are raycasting against THREE.Line or THREE.LineSegments, you should set the Line.threshold parameter to a value appropriate to the scale of your scene:
raycaster.params.Line.threshold = 0.1; // default is 1
three.js r.114
I'm rendering an object with textures using MTL and OBJ files with Three.js. My code here works but my model is displayed as flat shaded. How do I enable smooth shading?
var scene = new THREE.Scene();
var mtlLoader = new THREE.MTLLoader();
mtlLoader.setPath('assets/');
mtlLoader.setBaseUrl('assets/');
mtlLoader.load('asset.mtl', function(materials) {
materials.preload();
var objLoader = new THREE.OBJLoader();
objLoader.setMaterials(materials);
objLoader.setPath('assets/');
objLoader.load('asset.obj', function(object) {
//
// This solved my problem
//
object.traverse(function(child) {
if(child instanceof THREE.Mesh)
{
child.material.shading = THREE.SmoothShading;
}
});
//
//
scene.add(object);
});
});
EDIT:
I updated my code with a solution that fixed my problem based on the accepted answer.
It could be one of two things that I can think of right now.
It could be that the material is set to FlatShading. In this case just somehow retrieve the object and use object.material.shading = THREE.SmoothShading; to fix.
If that doesn't change it, it's possible that the object contains per-vertex-normals (meaning that every vertex of every triangle has a normal attached to it) and that all normals for each triangle point in the same direction. This is something that should better be solved in the 3d-editing process, but you can also re-compute the normals in three.js:
object.geometry.computeVertexNormals(true);
This should [1] recompute the normals for smooth surfaces. However, it will only work for regular Geometries and Indexed BufferGeometries (or, to put it the other way around: it won't work if the geometry doesn't have information about vertices being reused for adjacent faces)
[1]: I didn't test it myself and just go after what I just read in the code
You may need to smooth geometry as follows:
geometry = BufferGeometryUtils.mergeVertices(geometry, 0.1);
geometry.computeVertexNormals(true);
I've got grid of cylinder meshes created simply by
var tile = BABYLON.MeshBuilder.CreateCylinder("tile-" + i, { tessellation: 6, height: 0.1 }, scene);
then I have following event callback
window.addEventListener("click", function (evt) {
// try to pick an object
var pickResult = scene.pick(evt.clientX, evt.clientY);
if (pickResult.pickedMesh != null){
alert(pickResult.pickedMesh.name)
});
Then mouse-click on one of tiles raises message box with correct tile name.
When I add some new meshes (3D model inside .babylon file) by
var house;
BABYLON.SceneLoader.ImportMesh("", "../Content/"
, "house.babylon"
, scene
, function (newMeshes)
{ house = newMeshes[0]; });
For better imagination it's texture of house created from four different meshes which is placed over grid of cylinder tiles.
It's displayed fine but when mouse-click it too much often behave as it would totally ignore there is such a mesh and so pickResult.pickedMesh is either null or pickResult.pickedMesh.name points to tile underlaying my imported mesh in point I've clicked.
Just approximately 5% of mesh area corresponds properly to mouse-clicks (let's say in middle of roof, in middle of walls).
I've tried playing with setting some virtual (hidden) house.parent mesh for that which would not be created by importing meshes but seems as dead end.
Are you aware about some way how enforce that scene.pick(evt.clientX, evt.clientY); would respect mesh hierarchy and would consider all visible parts of overlaying texture?
Just for completeness I'm working with middle part of this 3D model (removed left and right house from that).
EDIT: Demo on BabylonJS playground
you could try change
var pickResult = scene.pick(evt.clientX, evt.clientY);
to
var pickResult = scene.pick(scene.pointerX, scene.pointerY);
as evt corresponds to whole page.
I am new to threejs.
I have scene with an object in it which we can move around the scene on all the XYZ Axis using TransformControls.js.
When I translate/move the object inside the scene using mouse click and drag on any of the axis (i.e X,Y,Z). I want to get the updated X,Y,Z position co-ordinates of that particular object inside the scene.
I use mesh.position.set( 0, 0, 0 ); to set position of the object prior rendering the scene, But I am not able to find how to get the dynamic position of an object inside a scene.
Eventually I want to save the updated position co-ordinates after the transform operation and re-render the scene with the object at the updated position co-ordinates when the user comes back to the page or does a page refresh.
Any pointers would be very helpful.
Thank you
THREE.TransformControls requires a few steps to use.
Create your THREE.TransformControls object
Add it to your scene
Attach it to the object you wish to manipulate
var xformControl = new THREE.TransformControls(camera, renderer.domElement);
scene.add(xformControls);
// assuming you add "myObj" to your scene...
xformControl.attach(myObj);
// and then later...
xformControl.detatch();
Attaching the control to an object will insert a manipulation "gizmo" into the scene. Dragging the various parts of the gizmo will perform different kinds of transformations. After you are done transforming the part with the gizmo, checking mesh.position should reflect the new position.
Additional information for clarity:
The position of the object will not be updated until you use the "gizmo" to move it. Example:
Your object is in the scene at (10, 10, 10)
xformControl.attach(yourObject)
The "gizmo" is created at (10, 10, 10)
Your object remains at (10, 10, 10)
Use the "gizmo" to translate the object in +Y direction
Your object will now have an updated position
console.log(yourObject.position.y > 10); // true
I might be too late, but you can get the updated value by using TransformControls' objectChange event.
Example code:
const transformControls = new TransformControls(camera, renderer.domElement);
transformControls.addEventListener('objectChange', (e) => {
console.log(e.target.object.position.x);
})
first answer is not correct, it should be:
onst transformControls = new TransformControls(camera, renderer.domElement);
transformControls.addEventListener('objectChange', (e) => {
console.log(e.target.object.position.x);
})
I'm using Physijs script for physics like gravitation.
I want to move objects in my scene with Raycaster from THREE.js script.
My problem is that Raycaster only move objects (simple box) declared like:
var box = new Physijs.Mesh(cubeGeomtery.clone(), createMaterial);
But here physics does not work. It only works if I declare it like:
var create = new Physijs.BoxMesh(cubeGeomtery.clone(), createMaterial);
But here Raycaster / moving does not work.
The difference between these two is that in the first it's just Mesh and in the second it's BoxMesh.
Does anyone know why this doesn't work? I need BoxMesh in order to use gravity and other physics.
Code to add cube
function addCube()
{
controls.enable = false;
var cubeGeomtery = new THREE.CubeGeometry(85, 85, 85);
var createTexture = new THREE.ImageUtils.loadTexture("images/rocks.jpg");
var createMaterial = new THREE.MeshBasicMaterial({ map: createTexture });
var box = new Physijs.BoxMesh(cubeGeomtery.clone(), createMaterial);
box.castShadow = true;
box.receiveShadow = true;
box.position.set(0, 300, 0);
objects.push(box);
scene.add(box);
}
Explanation
In Physijs, all primitive shapes (such as the Physijs.BoxMesh) inherit from Physijs.Mesh, which in turn inherits from THREE.Mesh. In the Physijs.Mesh constructor, there is a small internal object: the ._physijs field. And, in that object, there is... a shape type declaration, set to null by default. That field must be re-assigned by one of its children. If not, when the shape is passed to the scene, the Physijs worker script won't know what kind of shape to generate and simply abort. Since the Physijs.Scene inherits from the THREE.Scene, the scene keeps a reference of the mesh internally like it should, which means that all methods from THREE.js will work (raycasting, for instance). However, it is never registered as a physical object because it has no type!
Now, when you are trying to move the Physijs.BoxMesh directly with its position and rotation fields, it is immediately overridden by the physics updates, which started with the .simulate method in your scene object. When called, it delegates to the worker to compute new positions and rotations that correspond to the physics configurations in your scene. Once it's finished, the new values are transferred back to the main thread and updated automatically so that you don't have to do anything. This can be a problem in some cases (like this one!). Fortunately, the developer included 2 special fields in Physijs.Mesh: the .__dirtyPosition and .__dirtyRotation flags. Here's how you use them:
// Place box already in scene somewhere else
box.position.set(10, 10, 10);
// Set .__dirtyPosition to true to override physics update
box.__dirtyPosition = true;
// Rotate box ourselves
box.rotation.set(0, Math.PI, 0);
box.__dirtyRotation = true;
The flags get reset to false after updating the scene again via the .simulate method.
Conclusion
It is basically useless to create a Physijs.Mesh yourself, use one of the primitives provided instead. It is just a wrapper for THREE.Mesh for Physijs and has no physical properties until modified properly by one of its children.
Also, when using a Physijs mesh, always set either the .__dirtyPosition or the .__dirtyRotation property in the object to directly modify position or rotation, respectively. Take a look in the above code snippet and here.