three.js EdgesGeometry / Line Segments do not update after verticesNeedUpdate() - javascript

I created several three.js objects.
I noticed that 'other' objects designed as Mesh/Geometry/Material do update as expected after verticesNeedUpdate()
Additionally, I have two wireframe objects which I designed this way:
new THREE.LineSegments(new THREE.EdgesGeometry(new THREE.BoxGeometry(100,100,100), new THREE.LineBasicMaterial({color: 0xFF0000});
These objects do not update on verticesNeedUpdate(). My workaround right now is to delete them from scene and add them again on every change in the vertices, but I would like to perform this update more smart...
Thanks for any help!

Without seeing the rest of your code, it's hard to say.. however.. I'd guess that you're not re-using the box geometry that you are changing.
Try to create your box geometry on a separate line to ensure you're only using one box geometry, and not creating a new one inside of Line Segments.
var boxGeo = new THREE.BoxGeometry(100,100,100);
var lineMat = new THREE.LineBasicMaterial({color: 0xFF0000});
// use boxGeo in your other mesh
new THREE.LineSegments(new THREE.EdgesGeometry(boxGeo, lineMat));

Related

Overlaying texture onto STL loaded mesh

I'm looking for an efficient method of overlaying a texture to cover a mesh. I'm not an expert, more a novice, when it comes to 3 dimensional mapping/objects. Below shows how I would like the end product to look.
When attempting to apply texture with the following code, the end result looks similar to below. I have not done any UV mapping, I believe my answer may be lay here. As you can see from the below image it roughly takes the general shade of the picture but I get the impression that the texture is being drawn between each vertice of the model rather than across the entirity.
var textureLoader = new THREE.TextureLoader();
var texture = textureLoader.load('resource/images/materials/Mahogany.jpg');
var STLLoader = new THREE.STLLoader();
STLLoader.load( 'test.stl', function ( geometry1 ) {
var meshMaterial = new THREE.MeshBasicMaterial({map:texture});
var mesh = new THREE.Mesh( geometry1, meshMaterial );
mesh.scale.set(1, 1, 1);
mesh.position.set(5, 20, 80);
scene.add(mesh);
});
The cube has the correct texturing, whereas my STL loaded mesh does not.
Please ignore the rotation of the object in the above picture, I will move to unioning my objects together once I have fixed my texturing issues.
Fairly new at asking questions on here so please do comment to help me expand my question if it's too general or not percise enough. Thank you.
You may use
THREE.MeshPhongMaterial()
instead of
THREE.MeshBasicMaterial()
THREE.MeshPhongMaterial() will wrap the material outside the object and we can get curved material as per the object.

resizing individual models in a single geometry

I have a 3D model of my home town. I would like to use real time data to change the height of the buildings. In my first try, I loaded the buildings as individual meshes and called scene.add(buildingMesh) during setup.
var threeObjects = []
var buildingMesh = new THREE.Mesh(geometry, material)
threeObjects.push(buildingMesh);
$.each(threeObjects,function(i, buildingMesh)
{
buildingMesh.rotation.x += -3.1415*0.5;
buildingMesh.castShadow = true;
buildingMesh.receiveShadow = true;
scene.add(buildingMesh);
});
Which is too slow as my dataset consists of roughly 10.000 building.
So I took the approach to add all the (geometries of the) meshes to a single geometry and wrap that in a mesh to be added to the scene
singleGeometry.merge(buildingMesh.geometry, buildingMesh.matrix); //in a loop
var faceColorMaterial = new THREE.MeshLambertMaterial( { color: 0xffffff, vertexColors: THREE.VertexColors } );
combinedMesh = new THREE.Mesh(singleGeometry, faceColorMaterial);
scene.add(combinedMesh);
Just to make a proof of concept, I'm trying to change the height of a building when I click it. Alas, this is not working.
By adding a new id field, I can get a reference to the faces and vertices and change the color of the building, but I can not for the life of me, get them to to change height.
In my first version, I would just use something like:
buildingMesh.scale.z=2;
But as I have no meshes anymore, I'm kinda lost.
Can anybody help?
disclaimer: I'm new to Three.js, so my question might be stupid...hope it's not :)
If you combine all of your buildings into a single geometry, you're obliterating everything that makes the buildings distinct from each other. Now you can't tell building A from building B because it's all one big geometry, and geometry at its basic level is literally just arrays of points and polygons with no way of telling any of it apart. So I think it's the wrong approach to merge it all together.
Instead, you should take advantage of three.js's efficient scene graph architecture. You had the right idea at first to just add all the buildings to a single root Object3D ("scene"). That way you get all the efficiencies of the scene graph but can still individually address the buildings.
To make it load more efficiently, instead of creating the scene graph in three.js every time you load the app, you should do it ahead of time in a 3D modeling program. Build the parent/child relationships there, and export it as a single model containing all of the buildings as child nodes. When you import it into three.js, it should retain its structure.
JCD: That was not quite the question I asked.
But anyhow, I found a solution to the problem.
What I did was to merge all the geometries, but in stead of using the standard clone function in geometry.merge() I used a shallow reference, which made it possible for me to use the reference in threeObjects to find the correct building and resize the part of the geometry using Mesh.scale, followed by a geometry.verticesNeedUpdate = true;
For further optimization, I split the model into 5 different geometries and only updated the geometry that contained the building

How to Change a Box's dimensions/size after creation?

One can easily create a THREE.BoxGeometry where you have to pass arguments when creating as three separated arguments for width, height, and depth.
I would like to create any and all THREE[types]() with no parameters and set the values after that.
Is there a way to set the dimensions/size of the box geometry after creation (possibly buried in a Mesh already too)? other then scaling etc.
I couldn't find this in the documentation if so, otherwise maybe a major feature request if not a bug there. Any thoughts on how to classify this? maybe just a documentation change.
If you want to scale a mesh, you have two choices: scale the mesh
mesh.scale.set( x, y, z );
or scale the mesh's geometry
mesh.geometry.scale( x, y, z );
The first method modifies the mesh's matrix transform.
The second method modifies the vertices of the geometry.
Look at the source code so you understand what each scale method is doing.
three.js r.73
When you instantiate a BoxGeometry object, or any other geometry for that matter, the vertices and such buffers are created on the spot using the parameters provided. As such, it is not possible to simply change a property of the geometry and have the vertices update; the entire object must be re-instantiated.
You will need to create your geometries as you have the parameters for them available. You can however create meshes without geometries, add them to a scene, and update the mesh's geometry property once you have enough information to instantiate the object. If not that, you could also set a default value at first and then scale to reach your target.
Technically, scaling only creates the illusion of an updated geometry and the question did say (other then scaling). So, I would say a better approach would be to reassign the geometry property of your mesh to a new geometry.
mesh.geometry = new THREE.BoxGeometry(newSize, newSize, newSize)
With this approach you can update any aspect of the geometry including width segments for example. This is especially useful when working with non box geometries like cylinders or spheres.
Here is a full working example using this approach:
let size = 10
let newSize = 20
// Create a blank geometry and make a mesh from it.
let geometry = new THREE.BoxGeometry()
let material = new THREE.MeshNormalMaterial()
let mesh = new THREE.Mesh(geometry, material)
// Adding this mesh to the scene won't display anything because ...
// the geometry has no parameters yet.
scene.add(mesh)
// Unless you intend to reuse your old geometry dispose of it...
// this will significantly reduce memory footprint.
mesh.geometry.dispose()
// Update the mesh geometry to a new geometry with whatever parameters you desire.
// You will now see these changes reflected in the scene.
mesh.geometry = new THREE.BoxGeometry(size, size, size)
// You can update the geometry as many times as you like.
// This can be done before or after adding the mesh to the scene.
mesh.geometry = new THREE.BoxGeometry(newSize, newSize, newSize)

Raycaster does not move BoxMesh objects

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.

Three.js load multiple separated objects / JSONLoader

is it possible to load a scene (e.g. two different cubes) exported from blender to json and identify them?
I need to distinguish between them e.g. to make one rotating and the other moving.
Thank you in advance!
Denv
edit+++
Thank you for your answer!
So if I load two cubes in one JSON file:
loader.load("untitled1.js", function(geometry, materials) {
mesh = new THREE.Mesh( geometry, new THREE.MeshFaceMaterial(materials));
mesh.scale.set( 10, 10, 10 );
mesh.position.y = 0;
mesh.position.x = 0;
scene.add( mesh );
});
How can I move first cube?
mesh.getObjectById(0).position.x = 15;
Doesn't seems to work.
Thank you!
Yes, it is possible to load an entire scene from a json file exported from Blender!
I achieved that with the following process: (Using three.js r80)
First you have to name your different objects in Blender like in the following image Outliner.
Then you can export the file using Three.js json exporter add-on for Blender, but taking care of marking the Scene checkbox like in the following:
Using this option your json file now contains all the meshes on the Blender's Outliner, as you can verify using any text editor. It doesn't matter if the meshes were selected or not.
It is important to know that the root (or parent) object isn't a Geometry anymore. It is labeled with the Object type by now. To access the children objects (of Mesh type) you can use the getObjectByName method on the root object like in the following code:
jsonloader.load( "obj/Books.json", function ( loadedObj ) {
var surface = loadedObj.getObjectByName("Surface");
var outline = loadedObj.getObjectByName("Outline");
var mask = loadedObj.getObjectByName("Mask");
// Watch the objects properties on console:
console.log(loadedObj);
console.log(surface);
console.log(outline);
console.log(mask);
} );
If we check the browser's console, we can see the proper objects assigned. And from now, you can manipulate the children objects independently (move, rotate, change materials, etc.)
Each object loaded has an associated .id. So you can use the Object3D.getObjectById() to find it and apply transforms on it.

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