using a texture mesh and wireframe mesh in threejs - javascript

I'm trying to draw a wireframe mesh and a textured mesh in threeJS but when I have both added to my scene the textured mesh doesn't display. Code below:
I'm having trouble creating two meshes that share the same geometry where one of the materials is wireframe and the other is a texture. If one of the materials is wireframe and the other is just a color fill it works fine- but as soon as I make the second material a texture it stops working.
If I comment out scene.add( wireMesh ); then the textured mesh shows up.
var wireMat = new THREE.MeshBasicMaterial( { color:0x00FFFF, wireframe: true, transparent: true, overdraw:true } );
var wireMesh = new THREE.Mesh(geometry, wireMat);
scene.add( wireMesh );
var texture = texture = THREE.ImageUtils.loadTexture( 'textures/world.jpg' );
var imageMat = new THREE.MeshBasicMaterial( {color:0xffffff, map: texture } );
var fillMesh = new THREE.Mesh(geometry, imageMat);
scene.add( fillMesh );

Under SceneUtils there is a createMultiMaterialObject(geometry, materials). It essentially creates multiple meshes that all share the same geometry all in a group.
Example:
var mesh = THREE.SceneUtils.createMultiMaterialObject( geometry, [
new THREE.MeshLambertMaterial( { color: 0xffffff} ),
new THREE.MeshBasicMaterial( { color: 0x222222, wireframe: true} )
]);
THREE.SceneUtils source code

Unfortunately it is not possible to share geometry between an object using wireframe and another one not using it. You'd need to clone that geometry. Which reminds me that we haven't done .clone() for Geometry yet.

Related

How to set a texture to one side of a plane and have a color on the other side?

I'm trying to make a plane in three.js that one side is a texture and the other side is a color. I tried:
var material = new THREE.MeshBasicMaterial({color: 0xff0000, side: THREE.FrontSide, map: texture});
var geometry = new THREE.PlaneGeometry(width, height);
plane = new THREE.Mesh(geometry, material);
However this makes a plane that only one side has the texture and the other side is completely transparent. If I go:
var material = new THREE.MeshBasicMaterial({color: 0xff0000});
Then both sides have the color. Is there a way to make it so one side has a texture and the other side has the color?
Here is one patten you can follow if you want a different material on the front and back of a mesh:
var group = new THREE.Group();
scene.add( group );
group.add( new THREE.Mesh( geometry, new THREE.MeshBasicMaterial( { map: texture } ) ) );
group.add( new THREE.Mesh( geometry, new THREE.MeshBasicMaterial( { color: 0xff0000, side: THREE.BackSide } ) ) );
Another approach is to write your own custom ShaderMaterial, but the above is the easiest if you are just getting started with three.js
three.js r.104

Plane casts shadows on itself

I created a simple mesh in Blender, which consist only from one textured plane.
Blender screenshot
I import it in three.js with this code:
var texture2 = new THREE.TextureLoader().load('models/TexturesCom_Branches0030_1_S.png');
loader.load("models/plant.json", function (geometry, materials) {
materials.forEach(function (material) {
material.alphaTest = 0.5;
});
mesh = new THREE.Mesh( geometry, materials );
mesh.customDepthMaterial = new THREE.MeshDepthMaterial( {
side: THREE.DoubleSide,
depthPacking: THREE.RGBADepthPacking,
map: texture2,
alphaTest: 0.5
} );
mesh.castShadow = true;
mesh.receiveShadow = true;
scene.add(mesh);
});
That's how mesh looks in three.js: #1
#2
As you can see, object casts shadow not only on the ground, but on itself.
I can turn receiveShadow off, but this is not a solution for me. This problem does not disappear, if I create THREE.PlaneGeometry manually.

Three.js: viewangle affects texture strength

My mesh has a baked shadow texture.
Unfortunately I got a weird result If I move the camera to a steeper viewangle.
What can I do to prevent this ?
loader.load( "mesh.js", function(geometry){
var mesh = new THREE.Mesh( geometry, new THREE.MeshPhongMaterial( {
map: THREE.ImageUtils.loadTexture( "texture.png" ),
}));
scene.add(mesh);
});
Look at the example: http://threejs.org/examples/#webgl_materials_texture_anisotropy
Use:
var maxAnisotropy = renderer.getMaxAnisotropy();
texture.anisotropy = maxAnisotropy;
If you would like to learn more, you can look up Anisotropic Filtering.

Material DoubleSide - How to achieve different material on each side?

I have some generated geometries, where I want to see the faces from 2 sides.
So when looking from the front of one of the face's in the geometry, it is using material1 but viewed from the back you see material2.
I have experimentet with THREE.FrontSide, THREE.BackSide & THREE.DoubleSide, but none of them seem to give the wanted result. DoubleSide will just mirror the material on front and back.
Should I clone my geometry and create to meshes with two different materials ( mat1 = front & mat2 = back ) or what would you guys do?
Yes, two meshes with different materials should do the trick:.....
var material1 = new THREE.MeshBasicMaterial( { color: 0xff0000 } );
var material2 = new THREE.MeshBasicMaterial( { color: 0x0000ff, side: THREE.BackSide } );
var object1 = new THREE.Mesh( geometry, material1 );
var object2 = new THREE.Mesh( geometry, material2 );

Can I hide faces of a mesh in three.js?

I want to make parts of a mesh invisible at runtime. Can I set these parts invisible/transparent, e.g. by changing attributes of single faces? The mesh itself uses only one material.
Exemplary illustration as the editor understands this question: Imagine a mesh (here with a geometry of 20 vertices) where each quad of four vertices builds up a Face4. Now, some parts of the mesh should be made invisible (here two faces are invisible).
Note: This answer applies to legacy versions of three.js
You can assign a different material to each face. Here is an example where the faces share a material, but some faces are transparent:
// geometry
var geometry = new THREE.BoxGeometry( 100, 100, 100, 4, 4, 4 );
// materials
materials = [
new THREE.MeshLambertMaterial( { color: 0xffff00, side: THREE.DoubleSide } ),
new THREE.MeshBasicMaterial( { transparent: true, opacity: 0 } )
];
// assign material to each face
for( var i = 0; i < geometry.faces.length; i++ ) {
geometry.faces[ i ].materialIndex = THREE.Math.randInt( 0, 1 );
}
geometry.sortFacesByMaterialIndex(); // optional, to reduce draw calls
// mesh
mesh = new THREE.Mesh( geometry, materials );
scene.add( mesh );
three.js r.87

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