I'm working on a Three.js scene that loads 5 meshes, each with a single material that contains a single image texture. Once those images load, I'm attempting to accomplish the following tasks:
- load 20 higher resolution images
- update the material property of each mesh to load an array of 5 materials (each with 1 image texture) into each mesh
- update the faceVertexUvs of each mesh's geometry to point to the appropriate offsets within the new textures.
The documentation on Geometry has little to say about Geometry.faceVertexUvs, but this SO post suggests one can use the following approach to work with multiple materials in a geometry when using faceVertexUvs:
geometry.faceVertexUvs[ materialIndex ][ faceIndex ][ vertexIndex ]
The trouble is that after running through the steps above, I call meshes[meshIdx].geometry.uvsNeedUpdate = true; but my new materials are not appearing and my meshes stay unchanged. Does anyone have any idea why that might be?
I would be tremendously grateful for any pointers or insight others can offer on this question!
Here is my full code sample:
/**
* Globals
**/
// Create a store for all images contained in the visualization
var imageList = null;
// Create a store for the image atlas files. Each key will represent
// the index position of the atlas file, and the value will point
// to the material at that index position
var materials = {32: {}, 64: {}};
// Create global configs for image and atlas sizing
var image, atlas;
// Create a store of meshes
var meshes = [];
/**
* Create Scene
**/
// Create the scene and a camera to view it
var scene = new THREE.Scene();
/**
* Camera
**/
// Specify the portion of the scene visiable at any time (in degrees)
var fieldOfView = 75;
// Specify the camera's aspect ratio
var aspectRatio = window.innerWidth / window.innerHeight;
/*
Specify the near and far clipping planes. Only objects
between those planes will be rendered in the scene
(these values help control the number of items rendered
at any given time)
*/
var nearPlane = 100;
var farPlane = 50000;
// Use the values specified above to create a camera
var camera = new THREE.PerspectiveCamera(
fieldOfView, aspectRatio, nearPlane, farPlane
);
// Finally, set the camera's position
camera.position.z = 12000;
camera.position.y = -2000;
/**
* Renderer
**/
// Create the canvas with a renderer
var renderer = new THREE.WebGLRenderer({ antialias: true });
// Add support for retina displays
renderer.setPixelRatio( window.devicePixelRatio );
// Specify the size of the canvas
renderer.setSize( window.innerWidth, window.innerHeight );
// Add the canvas to the DOM
document.body.appendChild( renderer.domElement );
/**
* Load External Data
**/
// Identify data endpoint
var dataUrl = 'https://s3.amazonaws.com/duhaime/blog/tsne-webgl/data/';
// Create a store for image position information
var imagePositions = null;
// Load the image position JSON file
var fileLoader = new THREE.FileLoader();
fileLoader.load(dataUrl + 'image_tsne_projections.json', function(data) {
imagePositions = JSON.parse(data);
conditionallyBuildGeometries(32)
})
/**
* Load Atlas Textures
**/
// List of all textures to be loaded, the size of subimages
// in each, and the total number of atlas files for each size
var textureSets = {
32: { size: 32, count: 5 },
64: { size: 64, count: 20 }
}
// Create a texture loader so we can load our image files
var textureLoader = new THREE.TextureLoader();
function loadTextures(size) {
for (var i=0; i<textureSets[size].count; i++) {
var url = dataUrl + 'atlas_files/' + size + 'px/atlas-' + i + '.jpg';
textureLoader.load(url, handleTexture.bind(null, size, i));
}
}
// Callback function that adds the texture to the list of textures
// and calls the geometry builder if all textures have loaded
function handleTexture(size, idx, texture) {
var material = new THREE.MeshBasicMaterial({ map: texture });
materials[size][idx] = material;
conditionallyBuildGeometries(size, idx)
}
// If the textures and the mapping from image idx to positional information
// are all loaded, create the geometries
function conditionallyBuildGeometries(size, idx) {
if (size === 32) {
var nLoaded = Object.keys(materials[size]).length;
var nRequired = textureSets[size].count;
if (nLoaded === nRequired && imagePositions) {
document.querySelector('#loading').style.display = 'none';
buildGeometry(size);
loadTextures(64)
}
} else {
updateGeometry(size, idx)
}
}
loadTextures(32)
/**
* Build Image Geometry
**/
// Iterate over the textures in the current texture set
// and for each, add a new mesh to the scene
function buildGeometry(size) {
setImageAndAtlasSize(size);
for (var i=0; i<textureSets[size].count; i++) {
// Create one new geometry per atlas
var geometry = new THREE.Geometry();
for (var j=0; j<atlas.cols*atlas.rows; j++) {
geometry = updateVertices(geometry, i, j);
geometry = updateFaces(geometry);
geometry = updateFaceVertexUvs(geometry, j, 0);
}
buildMesh(geometry, materials[size][i]);
}
}
function setImageAndAtlasSize(size) {
// Identify the subimage size in px (width/height) and the
// size of the image as it will be displayed in the map
image = { width: size, height: size, shownWidth: 64, shownHeight: 64 };
// Identify the total number of cols & rows in the image atlas
atlas = { width: 2048, height: 2048, cols: 2048/size, rows: 2048/size };
}
// Get the x, y, z coords for the subimage at index position j
// of atlas in index position i
function getCoords(i, j) {
var idx = (i * atlas.rows * atlas.cols) + j;
var coords = imagePositions[idx];
coords.x *= 2200;
coords.y *= 1200;
coords.z = (-200 + j/100);
return coords;
}
// Add one vertex for each corner of the image, using the
// following order: lower left, lower right, upper right, upper left
function updateVertices(geometry, i, j) {
// Retrieve the x, y, z coords for this subimage
var coords = getCoords(i, j);
geometry.vertices.push(
new THREE.Vector3(
coords.x,
coords.y,
coords.z
),
new THREE.Vector3(
coords.x + image.shownWidth,
coords.y,
coords.z
),
new THREE.Vector3(
coords.x + image.shownWidth,
coords.y + image.shownHeight,
coords.z
),
new THREE.Vector3(
coords.x,
coords.y + image.shownHeight,
coords.z
)
);
return geometry;
}
// Create two new faces for a given subimage, then add those
// faces to the geometry
function updateFaces(geometry) {
// Add the first face (the lower-right triangle)
var faceOne = new THREE.Face3(
geometry.vertices.length-4,
geometry.vertices.length-3,
geometry.vertices.length-2
)
// Add the second face (the upper-left triangle)
var faceTwo = new THREE.Face3(
geometry.vertices.length-4,
geometry.vertices.length-2,
geometry.vertices.length-1
)
// Add those faces to the geometry
geometry.faces.push(faceOne, faceTwo);
return geometry;
}
function updateFaceVertexUvs(geometry, j, materialIdx) {
// Identify the relative width and height of the subimages
// within the image atlas
var relativeW = image.width / atlas.width;
var relativeH = image.height / atlas.height;
// Identify this subimage's offset in the x dimension
// An xOffset of 0 means the subimage starts flush with
// the left-hand edge of the atlas
var xOffset = (j % atlas.cols) * relativeW;
// Identify this subimage's offset in the y dimension
// A yOffset of 0 means the subimage starts flush with
// the bottom edge of the atlas
var yOffset = 1 - (Math.floor(j/atlas.cols) * relativeH) - relativeH;
// Create an empty list of faceVertexUvs for the given material Idx
// if it doesn't exist yet
if (!geometry.faceVertexUvs[materialIdx]) {
geometry.faceVertexUvs[materialIdx] = [];
}
// Use the xOffset and yOffset (and the knowledge that
// each row and column contains only 32 images) to specify
// the regions of the current image
geometry.faceVertexUvs[materialIdx][j*2] = [
new THREE.Vector2(xOffset, yOffset),
new THREE.Vector2(xOffset + relativeW, yOffset),
new THREE.Vector2(xOffset + relativeW, yOffset + relativeH)
];
// Map the region of the image described by the lower-left,
// upper-right, and upper-left vertices to `faceTwo`
geometry.faceVertexUvs[materialIdx][(j*2) + 1] = [
new THREE.Vector2(xOffset, yOffset),
new THREE.Vector2(xOffset + relativeW, yOffset + relativeH),
new THREE.Vector2(xOffset, yOffset + relativeH)
];
return geometry;
}
function buildMesh(geometry, material) {
// Convert the geometry to a BuferGeometry for additional performance
//var geometry = new THREE.BufferGeometry().fromGeometry(geometry);
// Combine the image geometry and material into a mesh
var mesh = new THREE.Mesh(geometry, [material]);
// Set the position of the image mesh in the x,y,z dimensions
mesh.position.set(0,0,0)
// Add the image to the scene
scene.add(mesh);
// Save this mesh
meshes.push(mesh);
}
/**
* Update Geometries with new VertexUvs and materials
**/
function updateGeometry(size, idx) {
// Update the image and atlas sizes
setImageAndAtlasSize(size)
// Determine how many of the higher resolution atlas files
// it takes to account for all subimages in a lower resolution
// atlas file
var lowResPerAtlas = (2048/32)**2;
var highResPerAtlas = (2048/64)**2;
var atlasRatio = lowResPerAtlas / highResPerAtlas;
// Determine which of the original meshes the newly-loaded high-res
// atlas corresponds to
var meshIdx = Math.floor(idx/atlasRatio);
// Determine the material index position to use in this mesh.
// The mesh's materials array will look like this:
// mesh.material = [32px, 64px_0, 64px_1, 64px_2, 64px_3, 64_px_4];
var materialIdx = (idx % atlasRatio) + 1;
// Add the newly loaded material into the appropriate mesh
meshes[meshIdx].material[materialIdx] = materials[size][idx];
//console.log(meshIdx, materialIdx, idx, meshes[materialIdx].material)
// Pluck out the geometry of this mesh update:
var geometry = meshes[meshIdx].geometry;
for (var j=0; j<highResPerAtlas; j++) {
geometry = updateFaceVertexUvs(geometry, j, materialIdx);
}
geometry.faceVertexUvs[0] = [];
meshes[meshIdx].geometry = geometry;
meshes[meshIdx].geometry.colorsNeedUpdate = true;
meshes[meshIdx].geometry.groupsNeedUpdate = true;
meshes[meshIdx].geometry.lineDistancesNeedUpdate = true;
meshes[meshIdx].geometry.normalsNeedUpdate = true;
meshes[meshIdx].geometry.uvsNeedUpdate = true;
meshes[meshIdx].geometry.verticesNeedUpdate = true;
// Indicate the material needs update
meshes[meshIdx].material.needsUpdate = true;
}
/**
* Lights
**/
// Add a point light with #fff color, .7 intensity, and 0 distance
var light = new THREE.PointLight( 0xffffff, 1, 0 );
// Specify the light's position
light.position.set(1, 1, 100);
// Add the light to the scene
scene.add(light)
/**
* Add Controls
**/
var controls = new THREE.TrackballControls(camera, renderer.domElement);
/**
* Handle window resizes
**/
window.addEventListener('resize', function() {
camera.aspect = window.innerWidth / window.innerHeight;
camera.updateProjectionMatrix();
renderer.setSize( window.innerWidth, window.innerHeight );
controls.handleResize();
});
/**
* Render!
**/
// The main animation function that re-renders the scene each animation frame
function animate() {
requestAnimationFrame( animate );
renderer.render( scene, camera );
controls.update();
}
animate();* {
margin: 0;
padding: 0;
background: #000;
color: #fff;
}<script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/88/three.js"></script>
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