mirror of
https://github.com/CesiumGS/obj2gltf.git
synced 2024-11-30 03:50:14 -05:00
546 lines
18 KiB
JavaScript
546 lines
18 KiB
JavaScript
'use strict';
|
|
const BUFFER_MAX_BYTE_LENGTH = require('buffer').constants.MAX_LENGTH;
|
|
const Cesium = require('cesium');
|
|
const getBufferPadded = require('./getBufferPadded');
|
|
const getDefaultMaterial = require('./loadMtl').getDefaultMaterial;
|
|
const Texture = require('./Texture');
|
|
|
|
const defaultValue = Cesium.defaultValue;
|
|
const defined = Cesium.defined;
|
|
const WebGLConstants = Cesium.WebGLConstants;
|
|
|
|
module.exports = createGltf;
|
|
|
|
/**
|
|
* Create a glTF from obj data.
|
|
*
|
|
* @param {Object} objData An object containing an array of nodes containing geometry information and an array of materials.
|
|
* @param {Object} options The options object passed along from lib/obj2gltf.js
|
|
* @returns {Object} A glTF asset.
|
|
*
|
|
* @private
|
|
*/
|
|
function createGltf(objData, options) {
|
|
const nodes = objData.nodes;
|
|
let materials = objData.materials;
|
|
const name = objData.name;
|
|
|
|
// Split materials used by primitives with different types of attributes
|
|
materials = splitIncompatibleMaterials(nodes, materials, options);
|
|
|
|
const gltf = {
|
|
accessors : [],
|
|
asset : {},
|
|
buffers : [],
|
|
bufferViews : [],
|
|
extensionsUsed : [],
|
|
extensionsRequired : [],
|
|
images : [],
|
|
materials : [],
|
|
meshes : [],
|
|
nodes : [],
|
|
samplers : [],
|
|
scene : 0,
|
|
scenes : [],
|
|
textures : []
|
|
};
|
|
|
|
gltf.asset = {
|
|
generator : 'obj2gltf',
|
|
version: '2.0'
|
|
};
|
|
|
|
gltf.scenes.push({
|
|
nodes : []
|
|
});
|
|
|
|
const bufferState = {
|
|
positionBuffers : [],
|
|
normalBuffers : [],
|
|
uvBuffers : [],
|
|
indexBuffers : [],
|
|
positionAccessors : [],
|
|
normalAccessors : [],
|
|
uvAccessors : [],
|
|
indexAccessors : []
|
|
};
|
|
|
|
const uint32Indices = requiresUint32Indices(nodes);
|
|
|
|
const nodesLength = nodes.length;
|
|
for (let i = 0; i < nodesLength; ++i) {
|
|
const node = nodes[i];
|
|
const meshes = node.meshes;
|
|
const meshesLength = meshes.length;
|
|
|
|
if (meshesLength === 1) {
|
|
const meshIndex = addMesh(gltf, materials, bufferState, uint32Indices, meshes[0], options);
|
|
addNode(gltf, node.name, meshIndex, undefined);
|
|
} else {
|
|
// Add meshes as child nodes
|
|
const parentIndex = addNode(gltf, node.name);
|
|
for (let j = 0; j < meshesLength; ++j) {
|
|
const mesh = meshes[j];
|
|
const meshIndex = addMesh(gltf, materials, bufferState, uint32Indices, mesh, options);
|
|
addNode(gltf, mesh.name, meshIndex, parentIndex);
|
|
}
|
|
}
|
|
}
|
|
|
|
if (gltf.images.length > 0) {
|
|
gltf.samplers.push({
|
|
magFilter : WebGLConstants.LINEAR,
|
|
minFilter : WebGLConstants.NEAREST_MIPMAP_LINEAR,
|
|
wrapS : WebGLConstants.REPEAT,
|
|
wrapT : WebGLConstants.REPEAT
|
|
});
|
|
}
|
|
|
|
addBuffers(gltf, bufferState, name, options.separate);
|
|
|
|
if (options.specularGlossiness) {
|
|
gltf.extensionsUsed.push('KHR_materials_pbrSpecularGlossiness');
|
|
gltf.extensionsRequired.push('KHR_materials_pbrSpecularGlossiness');
|
|
}
|
|
|
|
if (options.unlit) {
|
|
gltf.extensionsUsed.push('KHR_materials_unlit');
|
|
gltf.extensionsRequired.push('KHR_materials_unlit');
|
|
}
|
|
|
|
return gltf;
|
|
}
|
|
|
|
function addCombinedBufferView(gltf, buffers, accessors, byteStride, target) {
|
|
const length = buffers.length;
|
|
if (length === 0) {
|
|
return;
|
|
}
|
|
const bufferViewIndex = gltf.bufferViews.length;
|
|
const previousBufferView = gltf.bufferViews[bufferViewIndex - 1];
|
|
const byteOffset = defined(previousBufferView) ? previousBufferView.byteOffset + previousBufferView.byteLength : 0;
|
|
let byteLength = 0;
|
|
for (let i = 0; i < length; ++i) {
|
|
const accessor = gltf.accessors[accessors[i]];
|
|
accessor.bufferView = bufferViewIndex;
|
|
accessor.byteOffset = byteLength;
|
|
byteLength += buffers[i].length;
|
|
}
|
|
gltf.bufferViews.push({
|
|
name : 'bufferView_' + bufferViewIndex,
|
|
buffer : 0,
|
|
byteLength : byteLength,
|
|
byteOffset : byteOffset,
|
|
byteStride : byteStride,
|
|
target : target
|
|
});
|
|
}
|
|
|
|
function addCombinedBuffers(gltf, bufferState, name) {
|
|
addCombinedBufferView(gltf, bufferState.positionBuffers, bufferState.positionAccessors, 12, WebGLConstants.ARRAY_BUFFER);
|
|
addCombinedBufferView(gltf, bufferState.normalBuffers, bufferState.normalAccessors, 12, WebGLConstants.ARRAY_BUFFER);
|
|
addCombinedBufferView(gltf, bufferState.uvBuffers, bufferState.uvAccessors, 8, WebGLConstants.ARRAY_BUFFER);
|
|
addCombinedBufferView(gltf, bufferState.indexBuffers, bufferState.indexAccessors, undefined, WebGLConstants.ELEMENT_ARRAY_BUFFER);
|
|
|
|
let buffers = [];
|
|
buffers = buffers.concat(bufferState.positionBuffers, bufferState.normalBuffers, bufferState.uvBuffers, bufferState.indexBuffers);
|
|
const buffer = getBufferPadded(Buffer.concat(buffers));
|
|
|
|
gltf.buffers.push({
|
|
name : name,
|
|
byteLength : buffer.length,
|
|
extras : {
|
|
_obj2gltf : {
|
|
source : buffer
|
|
}
|
|
}
|
|
});
|
|
}
|
|
|
|
function addSeparateBufferView(gltf, buffer, accessor, byteStride, target, name) {
|
|
const bufferIndex = gltf.buffers.length;
|
|
const bufferViewIndex = gltf.bufferViews.length;
|
|
|
|
gltf.buffers.push({
|
|
name : name + '_' + bufferIndex,
|
|
byteLength : buffer.length,
|
|
extras : {
|
|
_obj2gltf : {
|
|
source : buffer
|
|
}
|
|
}
|
|
});
|
|
|
|
gltf.bufferViews.push({
|
|
buffer : bufferIndex,
|
|
byteLength : buffer.length,
|
|
byteOffset : 0,
|
|
byteStride : byteStride,
|
|
target : target
|
|
});
|
|
|
|
gltf.accessors[accessor].bufferView = bufferViewIndex;
|
|
gltf.accessors[accessor].byteOffset = 0;
|
|
}
|
|
|
|
function addSeparateBufferViews(gltf, buffers, accessors, byteStride, target, name) {
|
|
const length = buffers.length;
|
|
for (let i = 0; i < length; ++i) {
|
|
addSeparateBufferView(gltf, buffers[i], accessors[i], byteStride, target, name);
|
|
}
|
|
}
|
|
|
|
function addSeparateBuffers(gltf, bufferState, name) {
|
|
addSeparateBufferViews(gltf, bufferState.positionBuffers, bufferState.positionAccessors, 12, WebGLConstants.ARRAY_BUFFER, name);
|
|
addSeparateBufferViews(gltf, bufferState.normalBuffers, bufferState.normalAccessors, 12, WebGLConstants.ARRAY_BUFFER, name);
|
|
addSeparateBufferViews(gltf, bufferState.uvBuffers, bufferState.uvAccessors, 8, WebGLConstants.ARRAY_BUFFER, name);
|
|
addSeparateBufferViews(gltf, bufferState.indexBuffers, bufferState.indexAccessors, undefined, WebGLConstants.ELEMENT_ARRAY_BUFFER, name);
|
|
}
|
|
|
|
function addBuffers(gltf, bufferState, name, separate) {
|
|
const buffers = bufferState.positionBuffers.concat(bufferState.normalBuffers, bufferState.uvBuffers, bufferState.indexBuffers);
|
|
const buffersLength = buffers.length;
|
|
let buffersByteLength = 0;
|
|
for (let i = 0; i < buffersLength; ++i) {
|
|
buffersByteLength += buffers[i].length;
|
|
}
|
|
|
|
if (separate && (buffersByteLength > createGltf._getBufferMaxByteLength())) {
|
|
// Don't combine buffers if the combined buffer will exceed the Node limit.
|
|
addSeparateBuffers(gltf, bufferState, name);
|
|
} else {
|
|
addCombinedBuffers(gltf, bufferState, name);
|
|
}
|
|
}
|
|
|
|
function addTexture(gltf, texture) {
|
|
const imageName = texture.name;
|
|
const textureName = texture.name;
|
|
const imageIndex = gltf.images.length;
|
|
const textureIndex = gltf.textures.length;
|
|
|
|
gltf.images.push({
|
|
name : imageName,
|
|
extras : {
|
|
_obj2gltf : texture
|
|
}
|
|
});
|
|
|
|
gltf.textures.push({
|
|
name : textureName,
|
|
sampler : 0,
|
|
source : imageIndex
|
|
});
|
|
|
|
return textureIndex;
|
|
}
|
|
|
|
function getTexture(gltf, texture) {
|
|
let textureIndex;
|
|
const name = texture.name;
|
|
const textures = gltf.textures;
|
|
const length = textures.length;
|
|
for (let i = 0; i < length; ++i) {
|
|
if (textures[i].name === name) {
|
|
textureIndex = i;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (!defined(textureIndex)) {
|
|
textureIndex = addTexture(gltf, texture);
|
|
}
|
|
|
|
return {
|
|
index : textureIndex
|
|
};
|
|
}
|
|
|
|
function cloneMaterial(material, removeTextures) {
|
|
if (typeof material !== 'object') {
|
|
return material;
|
|
} else if (material instanceof Texture) {
|
|
if (removeTextures) {
|
|
return undefined;
|
|
}
|
|
return material;
|
|
} else if (Array.isArray(material)) {
|
|
const length = material.length;
|
|
const clonedArray = new Array(length);
|
|
for (let i = 0; i < length; ++i) {
|
|
clonedArray[i] = cloneMaterial(material[i], removeTextures);
|
|
}
|
|
return clonedArray;
|
|
}
|
|
const clonedObject = {};
|
|
for (const name in material) {
|
|
if (Object.prototype.hasOwnProperty.call(material, name)) {
|
|
clonedObject[name] = cloneMaterial(material[name], removeTextures);
|
|
}
|
|
}
|
|
return clonedObject;
|
|
}
|
|
|
|
function resolveTextures(gltf, material) {
|
|
for (const name in material) {
|
|
if (Object.prototype.hasOwnProperty.call(material, name)) {
|
|
const property = material[name];
|
|
if (property instanceof Texture) {
|
|
material[name] = getTexture(gltf, property);
|
|
} else if (!Array.isArray(property) && (typeof property === 'object')) {
|
|
resolveTextures(gltf, property);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
function addGltfMaterial(gltf, material, options) {
|
|
resolveTextures(gltf, material);
|
|
const materialIndex = gltf.materials.length;
|
|
if (options.unlit) {
|
|
if (!defined(material.extensions)) {
|
|
material.extensions = {};
|
|
}
|
|
material.extensions.KHR_materials_unlit = {};
|
|
}
|
|
gltf.materials.push(material);
|
|
return materialIndex;
|
|
}
|
|
|
|
function getMaterialByName(materials, materialName) {
|
|
const materialsLength = materials.length;
|
|
for (let i = 0; i < materialsLength; ++i) {
|
|
if (materials[i].name === materialName) {
|
|
return materials[i];
|
|
}
|
|
}
|
|
}
|
|
|
|
function getMaterialIndex(materials, materialName) {
|
|
const materialsLength = materials.length;
|
|
for (let i = 0; i < materialsLength; ++i) {
|
|
if (materials[i].name === materialName) {
|
|
return i;
|
|
}
|
|
}
|
|
}
|
|
|
|
function getOrCreateGltfMaterial(gltf, materials, materialName, options) {
|
|
const material = getMaterialByName(materials, materialName);
|
|
let materialIndex = getMaterialIndex(gltf.materials, materialName);
|
|
|
|
if (!defined(materialIndex)) {
|
|
materialIndex = addGltfMaterial(gltf, material, options);
|
|
}
|
|
|
|
return materialIndex;
|
|
}
|
|
|
|
function primitiveInfoMatch(a, b) {
|
|
return a.hasUvs === b.hasUvs &&
|
|
a.hasNormals === b.hasNormals;
|
|
}
|
|
|
|
function getSplitMaterialName(originalMaterialName, primitiveInfo, primitiveInfoByMaterial) {
|
|
let splitMaterialName = originalMaterialName;
|
|
let suffix = 2;
|
|
while (defined(primitiveInfoByMaterial[splitMaterialName])) {
|
|
if (primitiveInfoMatch(primitiveInfo, primitiveInfoByMaterial[splitMaterialName])) {
|
|
break;
|
|
}
|
|
splitMaterialName = originalMaterialName + '-' + suffix++;
|
|
}
|
|
return splitMaterialName;
|
|
}
|
|
|
|
function splitIncompatibleMaterials(nodes, materials, options) {
|
|
const splitMaterials = [];
|
|
const primitiveInfoByMaterial = {};
|
|
const nodesLength = nodes.length;
|
|
for (let i = 0; i < nodesLength; ++i) {
|
|
const meshes = nodes[i].meshes;
|
|
const meshesLength = meshes.length;
|
|
for (let j = 0; j < meshesLength; ++j) {
|
|
const primitives = meshes[j].primitives;
|
|
const primitivesLength = primitives.length;
|
|
for (let k = 0; k < primitivesLength; ++k) {
|
|
const primitive = primitives[k];
|
|
const hasUvs = primitive.uvs.length > 0;
|
|
const hasNormals = primitive.normals.length > 0;
|
|
const primitiveInfo = {
|
|
hasUvs : hasUvs,
|
|
hasNormals : hasNormals
|
|
};
|
|
const originalMaterialName = defaultValue(primitive.material, 'default');
|
|
const splitMaterialName = getSplitMaterialName(originalMaterialName, primitiveInfo, primitiveInfoByMaterial);
|
|
primitive.material = splitMaterialName;
|
|
primitiveInfoByMaterial[splitMaterialName] = primitiveInfo;
|
|
|
|
let splitMaterial = getMaterialByName(splitMaterials, splitMaterialName);
|
|
if (defined(splitMaterial)) {
|
|
continue;
|
|
}
|
|
|
|
const originalMaterial = getMaterialByName(materials, originalMaterialName);
|
|
if (defined(originalMaterial)) {
|
|
splitMaterial = cloneMaterial(originalMaterial, !hasUvs);
|
|
} else {
|
|
splitMaterial = getDefaultMaterial(options);
|
|
}
|
|
splitMaterial.name = splitMaterialName;
|
|
splitMaterials.push(splitMaterial);
|
|
}
|
|
}
|
|
}
|
|
return splitMaterials;
|
|
}
|
|
|
|
function addVertexAttribute(gltf, array, components, name) {
|
|
const count = array.length / components;
|
|
const minMax = array.getMinMax(components);
|
|
const type = (components === 3 ? 'VEC3' : 'VEC2');
|
|
|
|
const accessor = {
|
|
name : name,
|
|
componentType : WebGLConstants.FLOAT,
|
|
count : count,
|
|
min : minMax.min,
|
|
max : minMax.max,
|
|
type : type
|
|
};
|
|
|
|
const accessorIndex = gltf.accessors.length;
|
|
gltf.accessors.push(accessor);
|
|
return accessorIndex;
|
|
}
|
|
|
|
function addIndexArray(gltf, array, uint32Indices, name) {
|
|
const componentType = uint32Indices ? WebGLConstants.UNSIGNED_INT : WebGLConstants.UNSIGNED_SHORT;
|
|
const count = array.length;
|
|
const minMax = array.getMinMax(1);
|
|
|
|
const accessor = {
|
|
name : name,
|
|
componentType : componentType,
|
|
count : count,
|
|
min : minMax.min,
|
|
max : minMax.max,
|
|
type : 'SCALAR'
|
|
};
|
|
|
|
const accessorIndex = gltf.accessors.length;
|
|
gltf.accessors.push(accessor);
|
|
return accessorIndex;
|
|
}
|
|
|
|
function requiresUint32Indices(nodes) {
|
|
const nodesLength = nodes.length;
|
|
for (let i = 0; i < nodesLength; ++i) {
|
|
const meshes = nodes[i].meshes;
|
|
const meshesLength = meshes.length;
|
|
for (let j = 0; j < meshesLength; ++j) {
|
|
const primitives = meshes[j].primitives;
|
|
const primitivesLength = primitives.length;
|
|
for (let k = 0; k < primitivesLength; ++k) {
|
|
// Reserve the 65535 index for primitive restart
|
|
const vertexCount = primitives[k].positions.length / 3;
|
|
if (vertexCount > 65534) {
|
|
return true;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
function addPrimitive(gltf, materials, bufferState, uint32Indices, mesh, primitive, index, options) {
|
|
const hasPositions = primitive.positions.length > 0;
|
|
const hasNormals = primitive.normals.length > 0;
|
|
const hasUVs = primitive.uvs.length > 0;
|
|
|
|
const attributes = {};
|
|
if (hasPositions) {
|
|
const accessorIndex = addVertexAttribute(gltf, primitive.positions, 3, mesh.name + '_' + index + '_positions');
|
|
attributes.POSITION = accessorIndex;
|
|
bufferState.positionBuffers.push(primitive.positions.toFloatBuffer());
|
|
bufferState.positionAccessors.push(accessorIndex);
|
|
}
|
|
if (hasNormals) {
|
|
const accessorIndex = addVertexAttribute(gltf, primitive.normals, 3, mesh.name + '_' + index + '_normals');
|
|
attributes.NORMAL = accessorIndex;
|
|
bufferState.normalBuffers.push(primitive.normals.toFloatBuffer());
|
|
bufferState.normalAccessors.push(accessorIndex);
|
|
}
|
|
if (hasUVs) {
|
|
const accessorIndex = addVertexAttribute(gltf, primitive.uvs, 2, mesh.name + '_' + index + '_texcoords');
|
|
attributes.TEXCOORD_0 = accessorIndex;
|
|
bufferState.uvBuffers.push(primitive.uvs.toFloatBuffer());
|
|
bufferState.uvAccessors.push(accessorIndex);
|
|
}
|
|
|
|
const indexAccessorIndex = addIndexArray(gltf, primitive.indices, uint32Indices, mesh.name + '_' + index + '_indices');
|
|
const indexBuffer = uint32Indices ? primitive.indices.toUint32Buffer() : primitive.indices.toUint16Buffer();
|
|
bufferState.indexBuffers.push(indexBuffer);
|
|
bufferState.indexAccessors.push(indexAccessorIndex);
|
|
|
|
// Unload resources
|
|
primitive.positions = undefined;
|
|
primitive.normals = undefined;
|
|
primitive.uvs = undefined;
|
|
primitive.indices = undefined;
|
|
|
|
const materialIndex = getOrCreateGltfMaterial(gltf, materials, primitive.material, options);
|
|
|
|
return {
|
|
attributes : attributes,
|
|
indices : indexAccessorIndex,
|
|
material : materialIndex,
|
|
mode : WebGLConstants.TRIANGLES
|
|
};
|
|
}
|
|
|
|
function addMesh(gltf, materials, bufferState, uint32Indices, mesh, options) {
|
|
const gltfPrimitives = [];
|
|
const primitives = mesh.primitives;
|
|
const primitivesLength = primitives.length;
|
|
for (let i = 0; i < primitivesLength; ++i) {
|
|
gltfPrimitives.push(addPrimitive(gltf, materials, bufferState, uint32Indices, mesh, primitives[i], i, options));
|
|
}
|
|
|
|
const gltfMesh = {
|
|
name : mesh.name,
|
|
primitives : gltfPrimitives
|
|
};
|
|
|
|
const meshIndex = gltf.meshes.length;
|
|
gltf.meshes.push(gltfMesh);
|
|
return meshIndex;
|
|
}
|
|
|
|
function addNode(gltf, name, meshIndex, parentIndex) {
|
|
const node = {
|
|
name : name,
|
|
mesh : meshIndex
|
|
};
|
|
|
|
const nodeIndex = gltf.nodes.length;
|
|
gltf.nodes.push(node);
|
|
|
|
if (defined(parentIndex)) {
|
|
const parentNode = gltf.nodes[parentIndex];
|
|
if (!defined(parentNode.children)) {
|
|
parentNode.children = [];
|
|
}
|
|
parentNode.children.push(nodeIndex);
|
|
} else {
|
|
gltf.scenes[gltf.scene].nodes.push(nodeIndex);
|
|
}
|
|
|
|
return nodeIndex;
|
|
}
|
|
|
|
// Exposed for testing
|
|
createGltf._getBufferMaxByteLength = function() {
|
|
return BUFFER_MAX_BYTE_LENGTH;
|
|
};
|