I'm loading an object from .obj & .mtl files. It looks like this:
What I'm trying to achieve here is that I want to be-able to identify each of the different sides on the bag so I can change each sides colour individually.
I've examined the object and it contains the following:
I've tried to create an array of uniquely coloured materials and apply them like so:
var materials = [
new THREE.MeshPhongMaterial({color: 0x80ffaa}), // Light green
new THREE.MeshPhongMaterial({color: 0xe60000}), // Red
new THREE.MeshPhongMaterial({color: 0xff4dff}), // Pink
new THREE.MeshPhongMaterial({color: 0x3399ff}), // Light blue
new THREE.MeshPhongMaterial({color: 0xac7339}), // Brown
new THREE.MeshPhongMaterial({color: 0x666699}) // Purple
];
var material = new THREE.MeshFaceMaterial(materials)
this.selectedProduct[0]['children'][0].material.materials = materials;
but it appeared like so:
So only three colours were applied to it. The model I'm using is exported out of Blender and so that's where I get my .obj & .mtl files and in the .mtl file it only applies three materials.
So how do I go about getting and updating each side?
EDIT
#pailhead
I've examined the object in Blender and as far as I can see, each of those sides should be unique. Here's the edit view of the object:
So I should be-able to apply a different material to each side then right?
EDIT 2
I'm confused as to what's happening here. I've merged the lip of the bag with the side it was one to create one side each for the bigger sides. Applying the same materials and colour I get this:
The side under each of the handles is one side only - so why am I getting two different colours appearing?
You tried to apply six different materials to a model, and saw only three as a result.
What would have happened if you decided that you needed to provide 7 different materials, or 12 or even 2? The information that should describe whether this model has 3 "different sides" or 6 or 9 is in the .obj file, which does not change no matter how many different materials you apply with three.js.
Is it safe to assume that this particular obj only holds enough information to distinguish between three different faces? I'd say so.
This means that you need to create a different model describing the material relations differently. Go back to blender, assign more ids, or break the mesh apart into "sides" and you'll have logical entities to work with.
Otherwise, you can extract sub meshes out of your geometry. This is complicated but you could build a structure that would allow you to walk the faces. You could then set some kind of thresholds of rules as to where the boundaries should be (like, extract everything that is less than 45 degrees away from the +Y axis, and is connected to face 563).
Related
I'm able to load in a model using assimp with:
SceneNode _sceneModel = new Importer().Load(path).Root;
This seems to load in the geometry into its separate meshes - for instance if in Maya you built a room with Wall_1, Wall_2, Wall_3, etc. the SceneNode is some kind of data structure with all the meshes.
The separate meshes can then be put into an array
geometry = _sceneModel.Traverse().Where(x => (x is MeshNode)).Select(m => ((MeshNode)m).Geometry).ToArray();
But ultimately I just want to bind the entire single piece of geometry (eg a house) in xml to
<MeshGeometryModel3D>
but can't figure out how to do it. I can bind a single piece of geometry eg. from the geometry array I can bind geometry[1] which might represent a wall but can't workout how to bind the whole thing.
Thanks
MeshGeometryModel3D is a wpf wrapper for Mesh Node (which is a scene node). If you only want to display your loaded model, you can add the root scene node into a GroupNodeModel3D.
You can find example here
https://github.com/helix-toolkit/helix-toolkit/blob/2254fce0870a165352ccb888e2f3e17398751724/Source/Examples/WPF.SharpDX/FileLoadDemo/MainViewModel.cs#L128
I'm using three.js library to work with 3d models (mostly .glb but it shouldn't matter)
The idea is to import a 3d model that contains groups and meshes. I want to be able to move meshes between already existing groups within a model without changing the visual representation of the model.
Piece of my code is below. movedInternal is
movedMesh.matrixWorldNeedsUpdate = true; // not sure if it's needed
let meshPosition = new THREE.Vector3();
movedMesh.getWorldPosition(meshPosition);
oldParent.remove(movedMesh);
newParent.add(movedMesh);
movedMesh.worldToLocal(meshPosition);
movedMesh.position.set(meshPosition.x, meshPosition.y, meshPosition.z);
And this is not working. Mesh changes its global position because new parent’s position is not the same as previous parent position, but I expect it to stay where it was but change its local position considering new parent’s position.
What do I do wrong?
I think you need to update the movedMesh's world matrix after you change its parents. When you .remove() then .add(), it doesn't know that its parents have been updated (Three.js usually does it when you're rendering, but this is happening before the next frame render).
let meshPosition = new THREE.Vector3();
movedMesh.getWorldPosition(meshPosition);
oldParent.remove(movedMesh);
newParent.add(movedMesh);
// Here it needs to re-learn its new coordinates
movedMesh.updateMatrixWorld(true);
movedMesh.worldToLocal(meshPosition);
movedMesh.position.set(meshPosition.x, meshPosition.y, meshPosition.z);
I've been searching for this solution since a week and haven't been able to tackle the exact problem. Though my question is diferent but has same scenario, I would like to give a solution for those, looking for it.
I have a 3D object with different child meshes, and i want to replace one of my child mesh with another 3D model.
Below code snippet:
replacementMesh is a new 3D object, meshToReplace is the child mesh that needs to be replaced.
// Copy the transformation matrix from obj1 to obj2
replacementMesh.matrix.copy(meshToReplace.matrix);
// Update obj2's position, rotation, and scale to match the transformation matrix
replacementMesh.position.setFromMatrixPosition(replacementMesh.matrix);
replacementMesh.rotation.setFromRotationMatrix(replacementMesh.matrix);
replacementMesh.scale.setFromMatrixScale(replacementMesh.matrix);
meshToReplace.parent.add(replacementMesh);
meshToReplace.parent.remove(meshToReplace);
I’m having a hard time getting an aoMap working in three.js…
I have a glb asset with an aoMap on the red channel or something. When I bring it into to the babylon viewer, I can see the ao just fine, but it wont show up in the three.js viewer or my project. I think this has something to do with a second set of uvs, but I can't find a resource that involves doing that on top of using the gltf loader… I really don't know what to do here. Any response would be greatly appreciated!
Here is my code (I’m using a html-canvas as the texture)
And I get the model’s geometry and diffuse texture (all white) as desired, but the aomap isnt showing…
code
babylon viewer
three.js viewer
working application with shadows included in diffuse
not working, diffuse is just white, and aoMap is not showing
You're right about needing a second set of UVs. The reason behind this is that diffuse textures often repeat (think of a brick wall, or checkered t-shirt). AO shading, however, is more likely to be unique on each part of the geometry, so it's almost never repetitive. Since this often would need an alternative UV mapping method, the default is to use a second set of UVs.
You could do 2 things:
Re-export your GLTF asset with a duplicate set of UVs.
Duplicate existing UVs in Three.js by creating a new BufferAttribute in your geometry:
// Get existing `uv` data array
const uv1Array = mesh.geometry.getAttribute("uv").array;
// Use this array to create new attribute named `uv2`
mesh.geometry.setAttribute( 'uv2', new THREE.BufferAttribute( uv1Array, 2 ) );
.getAttribute and .setAttribute are methods of BufferGeometry, if you want to read more about them.
I have made a small scene in blender (6 objects, each using 1 to 4 materials).
When exporting this (using the materials, and the scene option) with the dev exporter and loading it via:
var loader = new THREE.ObjectLoader();
loader.load( 'assets/scene.json', function ( scene ) { ...
And then checking the scene, I can see it has 6 children (good) and that each of the five children only has one MeshLambertMaterial (instead of the material mix from blender) bad.
Any hints on what I am doing wrong?
Those are btw basic materials (just a color basically) no textures or anything.
The scene renders correctly (minus the material mix).
Here is a link to the 113kb scene file (zipped): http://jppresents.net/static/blender/exportBug/scene.zip
Looking at the file I think all materials are there - so the problem must be the way I load it?
Not a solution, but a work around:
Since the only difference between all my materials was just the color, I have now applied exactly one material with a multi colored texture per object.
Then I uv-mapped the faces of the object to the colors corresponding to the previously set material color.
This was easy using the hotkey "shift + G" which lets you select all faces with the same material. (Then just assign them to the texture material, move/scale those in the uv-view to the part of the texture that matches the old color.)
We are studying on product designer project. Designer is ready.
I want to do 3d preview result with three.js.
How can we texture one side of phone case? or can we border texture mapping?
OBJLoader version:
http://www.shopilife.com/baskiburada/viewer/viewer_4.html
And some obj files cannot be textured. Error is "GL_INVALID_OPERATION : glDrawElements: attempt to access out of range vertices in attribute 2"
http://www.shopilife.com/baskiburada/viewer/viewer2.html
First, regarding re-texturing the back vs. front of the phone case. The approach here is to seperate the UV coordinates on the model itself. This way you have two sets of materials/textures/UVs. Then during runtime you load them both using a MeshFaceMaterial to load the two materials in an array like so:
materialArray.push(THREE.BasicMeshMaterial({color: 0xff0000})); //use whatever Material type you'd like of course
materialArray.push(THREE.BasicMeshMaterial({color: 0x0000ff}));
var multipleMaterial = new THREE.MeshFaceMaterial(materialArray);
phoneCaseMesh= new THREE.Mesh( geometry, multipleMaterial );
Then when you want to switch one out you would grab the mesh and change the mapping to the desired side something like:
phoneCaseMesh.material.materials[1].map = THREE.ImageUtils.loadTexture( 'newtexture.jpg' );
Second, regarding the Error on you second sample, WestLangley is correct the OBJ file has no UV coordinates to map to, so the index is out of bounds when you apply a texture. If you look at both OBJ files your iphone4.obj has vt entities while the untitled.obj is just v and f. Hope that helps