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cleanup edits
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@rahwang
rahwang committed Jul 27, 2017
1 parent 9da383e commit 563d524
Showing 1 changed file with 110 additions and 97 deletions.
207 changes: 110 additions & 97 deletions lib/loadObj.js
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Original file line number Diff line number Diff line change
Expand Up @@ -100,12 +100,11 @@ function loadObj(objPath, options) {
var lineBuffer = '';

// Used for parsing face data
var faceVertices = []; // names of vertices for caching
var facePositions = []; // indices into position array
var faceUvs = []; // indices into uv array
var faceNormals = []; // indices into normal array
var faceVertices = [];
var facePositions = [];
var faceUvs = [];
var faceNormals = [];

var positions3D = [];
var vertexIndices = [];

function getName(name) {
Expand Down Expand Up @@ -152,95 +151,6 @@ function loadObj(objPath, options) {
primitive.material = getName(name);
}

var intPoint = new Cartesian3();
var xAxis = Cesium.Cartesian3.UNIT_X.clone();
var yAxis = Cesium.Cartesian3.UNIT_Y.clone();
var zAxis = Cesium.Cartesian3.UNIT_Z.clone();
var origin = new Cartesian3();
var normal = new Cartesian3();
var ray = new Ray();
var plane = new Plane(Cesium.Cartesian3.UNIT_X, 0);

function projectTo2D(positions) {
var i;
var positions2D = new Array(positions.length);
var obb = OrientedBoundingBox.fromPoints(positions);
var halfAxes = obb.halfAxes;
Matrix3.getColumn(halfAxes, 0, xAxis);
Matrix3.getColumn(halfAxes, 1, yAxis);
Matrix3.getColumn(halfAxes, 2, zAxis);

var xMag = Cartesian3.magnitude(xAxis);
var yMag = Cartesian3.magnitude(yAxis);
var zMag = Cartesian3.magnitude(zAxis);
var min = Math.min(xMag, yMag, zMag);

// If all the points are on a line, just remove one of the zero dimensions
if (xMag === 0 && (yMag === 0 || zMag === 0)) {
for (i = 0; i < positions.length; i++) {
positions2D[i] = new Cartesian2(positions[i].y, positions[i].z);
}
return positions2D;
} else if (yMag === 0 && zMag === 0) {
for (i = 0; i < positions.length; i++) {
positions2D[i] = new Cartesian2(positions[i].x, positions[i].y);
}
return positions2D;
}

var center = obb.center;
var planeXAxis;
var planeYAxis;
if (min === xMag) {
if (!xAxis.equals(Cartesian3.ZERO)) {
Cartesian3.add(center, xAxis, origin);
Cartesian3.normalize(xAxis, normal);
}
planeXAxis = Cartesian3.normalize(yAxis, yAxis);
planeYAxis = Cartesian3.normalize(zAxis, zAxis);
} else if (min === yMag) {
if (!yAxis.equals(Cartesian3.ZERO)) {
Cartesian3.add(center, yAxis, origin);
Cartesian3.normalize(yAxis, normal);
}
planeXAxis = Cartesian3.normalize(xAxis, xAxis);
planeYAxis = Cartesian3.normalize(zAxis, zAxis);
} else {
if (!zAxis.equals(Cartesian3.ZERO)) {
Cartesian3.add(center, zAxis, origin);
Cartesian3.normalize(zAxis, normal);
}
planeXAxis = Cartesian3.normalize(xAxis, xAxis);
planeYAxis = Cartesian3.normalize(yAxis, yAxis);
}

if (min === 0) {
normal = Cartesian3.cross(planeXAxis, planeYAxis, normal);
normal = Cartesian3.normalize(normal, normal);
}

Plane.fromPointNormal(origin, normal, plane);
ray.direction = normal;

for (i = 0; i < positions.length; i++) {
ray.origin = positions[i];

var intersectionPoint = IntersectionTests.rayPlane(ray, plane, intPoint);

if (!defined(intersectionPoint)) {
Cartesian3.negate(ray.direction, ray.direction);
intersectionPoint = IntersectionTests.rayPlane(ray, plane, intPoint);
}
var v = Cartesian3.subtract(intersectionPoint, origin, intersectionPoint);
var x = Cartesian3.dot(planeXAxis, v);
var y = Cartesian3.dot(planeYAxis, v);

positions2D[i] = new Cartesian2(x, y);
}

return positions2D;
}

function getOffset(a, attributeData, components) {
var i = parseInt(a);
if (i < 0) {
Expand Down Expand Up @@ -301,6 +211,106 @@ function loadObj(objPath, options) {
return index;
}

// Given a set of 3D points, project them onto whichever axis will produce the least distortion.
var scratchIntersectionPoint = new Cartesian3();
var scratchXAxis = new Cartesian3();
var scratchYAxis = new Cartesian3();
var scratchZAxis = new Cartesian3();
var scratchOrigin = new Cartesian3();
var scratchNormal = new Cartesian3();
var scratchRay = new Ray();
var scratchPlane = new Plane(Cesium.Cartesian3.UNIT_X, 0);
var scratchPositions2D = [new Cartesian2(), new Cartesian2(), new Cartesian2()];
function projectTo2D(positions) {
var positions2D = [];
var obb = OrientedBoundingBox.fromPoints(positions);
var halfAxes = obb.halfAxes;
Matrix3.getColumn(halfAxes, 0, scratchXAxis);
Matrix3.getColumn(halfAxes, 1, scratchYAxis);
Matrix3.getColumn(halfAxes, 2, scratchZAxis);

var xMag = Cartesian3.magnitude(scratchXAxis);
var yMag = Cartesian3.magnitude(scratchYAxis);
var zMag = Cartesian3.magnitude(scratchZAxis);
var min = Math.min(xMag, yMag, zMag);

var i;
// If all the points are on a line, just remove one of the zero dimensions
if (xMag === 0 && (yMag === 0 || zMag === 0)) {
for (i = 0; i < positions.length; i++) {
if (i === scratchPositions2D.length) {
scratchPositions2D.push(new Cartesian2());
}
positions2D[i] = new Cartesian2.fromElements(positions[i].y, positions[i].z, scratchPositions2D[i]);
}
return positions2D;
} else if (yMag === 0 && zMag === 0) {
for (i = 0; i < positions.length; i++) {
if (i === scratchPositions2D.length) {
scratchPositions2D.push(new Cartesian2());
}
positions2D[i] = new Cartesian2.fromElements(positions[i].x, positions[i].y, scratchPositions2D[i]);
}
return positions2D;
}

var center = obb.center;
var planeXAxis;
var planeYAxis;
if (min === xMag) {
if (!scratchXAxis.equals(Cartesian3.ZERO)) {
Cartesian3.add(center, scratchXAxis, scratchOrigin);
Cartesian3.normalize(scratchXAxis, scratchNormal);
}
planeXAxis = Cartesian3.normalize(scratchYAxis, scratchYAxis);
planeYAxis = Cartesian3.normalize(scratchZAxis, scratchZAxis);
} else if (min === yMag) {
if (!scratchYAxis.equals(Cartesian3.ZERO)) {
Cartesian3.add(center, scratchYAxis, scratchOrigin);
Cartesian3.normalize(scratchYAxis, scratchNormal);
}
planeXAxis = Cartesian3.normalize(scratchXAxis, scratchXAxis);
planeYAxis = Cartesian3.normalize(scratchZAxis, scratchZAxis);
} else {
if (!scratchZAxis.equals(Cartesian3.ZERO)) {
Cartesian3.add(center, scratchZAxis, scratchOrigin);
Cartesian3.normalize(scratchZAxis, scratchNormal);
}
planeXAxis = Cartesian3.normalize(scratchXAxis, scratchXAxis);
planeYAxis = Cartesian3.normalize(scratchYAxis, scratchYAxis);
}

if (min === 0) {
scratchNormal = Cartesian3.cross(planeXAxis, planeYAxis, scratchNormal);
scratchNormal = Cartesian3.normalize(scratchNormal, scratchNormal);
}

Plane.fromPointNormal(scratchOrigin, scratchNormal, scratchPlane);
scratchRay.direction = scratchNormal;

for (i = 0; i < positions.length; i++) {
scratchRay.origin = positions[i];

var intersectionPoint = IntersectionTests.rayPlane(scratchRay, scratchPlane, scratchIntersectionPoint);

if (!defined(intersectionPoint)) {
Cartesian3.negate(scratchRay.direction, scratchRay.direction);
intersectionPoint = IntersectionTests.rayPlane(scratchRay, scratchPlane, scratchIntersectionPoint);
}
var v = Cartesian3.subtract(intersectionPoint, scratchOrigin, intersectionPoint);
var x = Cartesian3.dot(planeXAxis, v);
var y = Cartesian3.dot(planeYAxis, v);

if (i === scratchPositions2D.length) {
scratchPositions2D.push(new Cartesian2());
}

positions2D[i] = new Cartesian2.fromElements(x, y, scratchPositions2D[i]);
}

return positions2D;
}

function get3DPoint(index, result) {
var pi = getOffset(index, positions, 3);
var px = positions.get(pi + 0);
Expand Down Expand Up @@ -365,7 +375,7 @@ function loadObj(objPath, options) {
}
}

var scratchNormal = new Cartesian3();
var scratchPositions3D = [new Cartesian3(), new Cartesian3(), new Cartesian3()];
function addFace(vertices, positions, uvs, normals) {
var isWindingCorrect = true;
var faceNormal;
Expand All @@ -383,7 +393,7 @@ function loadObj(objPath, options) {
var index3 = addVertex(vertices[2], positions[2], uvs[2], normals[2]);
addTriangle(index1, index2, index3, isWindingCorrect);
} else { // Triangulate if the face is not a triangle
positions3D.length = 0;
var positions3D = [];
vertexIndices.length = 0;

var i;
Expand All @@ -392,7 +402,10 @@ function loadObj(objPath, options) {
vertexIndices.push(index);

// Collect the vertex positions as 3D points
positions3D.push(get3DPoint(positions[i], new Cartesian3()));
if (i === scratchPositions3D.length) {
scratchPositions3D.push(new Cartesian3());
}
positions3D.push(get3DPoint(positions[i], scratchPositions3D[i]));
}

var positions2D = projectTo2D(positions3D);
Expand Down

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