return this.closed_trianglefan([apex].concat(base)).concat(
this.trianglefan(base.reverse()));
},
+ sphere: function(center, radius, latitude_steps, longitude_steps) {
+ return this.oriented_sphere(center, radius, [0,0,1], [1,0,0], latitude_steps, longitude_steps);
+ },
+ oriented_sphere: function(center, radius, north, greenwich, latitude_steps, longitude_steps) {
+ var unit_north = this.unit(north);
+ var north_pole = this.translate_point(this.scale(unit_north, radius), center);
+ var south_pole = this.translate_point(this.scale(unit_north, -radius), center);
+ return this.spheroid(north_pole, south_pole, radius, greenwich, latitude_steps, longitude_steps);
+ },
+ spheroid: function(north_pole, south_pole, radius, greenwich, latitude_steps, longitude_steps) {
+ var delta = this.sub(north_pole, south_pole);
+ var path = [];
+ for (var i = 0; i < latitude_steps-1; i++) {
+ path.push(this.translate_point(south_pole, this.scale(delta, (1-Math.cos(Math.PI*i/(latitude_steps-1)))/2)));
+ }
+ path.push(north_pole);
+ function shape(i) {
+ return nt3d.circle(radius*Math.sin(Math.PI*i/(latitude_steps-1)), longitude_steps);
+ }
+ return this.extrude(path, shape, delta, greenwich);
+ },
+ shapenormals_from_closed_path: function(path) {
+ return function(i) {
+ var prev = (i == 0) ? path.length-1 : i-1;
+ var next = (i == path.length-1) ? 0 : i+1;
+ return nt3d.sub(path[next], path[prev]);
+ };
+ },
+ shapenormals_from_path_and_extra_points: function(path, first_point, last_point) {
+ return function(i) {
+ var prev = (i == 0) ? first_point : path[i-1];
+ var next = (i == path.length-1) ? last_point : path[i+1];
+ return nt3d.sub(next, prev);
+ };
+ },
+ shapenormals_from_path_and_first_and_last_normals: function(path, first_normal, last_normal) {
+ return function(i) {
+ if (i == 0) { return first_normal; }
+ if (i == path.length-1) { return last_normal; }
+ return nt3d.sub(path[i+1], path[i-1]);
+ };
+ },
+ pathnormals_from_point: function(path, p) {
+ // Use this with any point that is not on any path tangent line
+ var pathnormals = [];
+ for (var i = 0; i < path.length; i++) {
+ pathnormals.push(this.sub(path[i], p));
+ }
+ return pathnormals;
+ },
to_function: function(thing, make_indexer) {
// If thing is a point, just yield thing every time.
// If thing is a list of points && make_indexer, index into thing.
},
extrude: function(path, shape, shapenormals, pathnormals) {
- var guts_result = nt3d._extrude_guts(path, shape, shapenormals, pathnormals);
+ var guts_result = this._extrude_guts(path, shape, shapenormals, pathnormals);
// Add the end-caps
// XXX: This doesn't work if shape is not convex
return guts_result.points.concat(
- nt3d.trianglefan(guts_result.first_loop.reverse()),
- nt3d.trianglefan(guts_result.last_loop));
+ this.trianglefan(guts_result.first_loop.reverse()),
+ this.trianglefan(guts_result.last_loop));
},
closed_extrude: function(path, shape, shapenormals, pathnormals) {
- var guts_result = nt3d._extrude_guts(path, shape, shapenormals, pathnormals);
+ var guts_result = this._extrude_guts(path, shape, shapenormals, pathnormals);
// Stitch the ends together
return guts_result.points.concat(
- nt3d.closed_quadstrip(nt3d.zip(guts_result.first_loop, guts_result.last_loop)));
+ this.closed_quadstrip(this.zip(guts_result.first_loop, guts_result.last_loop)));
},
_extrude_guts: function(path, shape, shapenormals, pathnormals) {
var shape_fun = this.to_function(shape, false);
if (i == 0) {
result.first_loop = loop;
} else {
- result.points = result.points.concat(nt3d.closed_quadstrip(nt3d.zip(loop, prev_loop)));
+ result.points = result.points.concat(this.closed_quadstrip(this.zip(loop, prev_loop)));
}
prev_loop = loop;
}
},
project: function(a, b) { // Project b onto a
var a_magnitude = this.magnitude(a);
- return this.scale(a, this.dot(a, b) / a_magnitude * a_magnitude);
+ return this.scale(a, this.dot(a, b) / (a_magnitude * a_magnitude));
},
project_to_orthogonal: function(a, b) {
// The nearest thing to b that is orthogonal to a
translate: function(points, offset) {
var translated = [];
for (var i = 0; i < points.length; i++) {
- translated[i] = [points[i][0] + offset[0],
- points[i][1] + offset[1],
- points[i][2] + offset[2]];
+ translated[i] = this.translate_point(points[i], offset);
}
return translated;
},
+ translate_point: function(point, offset) {
+ return [point[0] + offset[0],
+ point[1] + offset[1],
+ point[2] + offset[2]];
+ },
angle_between: function(a, b) { // a and b must be unit vectors
- return Math.acos(this.dot(a, b));
+ var the_dot = this.dot(a, b);
+ if (the_dot <= -1) {
+ return Math.PI;
+ }
+ if (the_dot >= 1) {
+ return 0;
+ }
+ return Math.acos(the_dot);
},
rotate_about_origin: function(points, axis, angle) { // axis must be a unit vector
// From http://inside.mines.edu/~gmurray/ArbitraryAxisRotation/
angle),
center);
},
+ point_equal: function(a, b, epsilon) {
+ return Math.abs(a[0] - b[0]) < epsilon &&
+ Math.abs(a[1] - b[1]) < epsilon &&
+ Math.abs(a[2] - b[2]) < epsilon;
+ },
+ degenerate_face_epsilon: 1e-10,
+ is_degenerate: function(a, b, c) {
+ return this.point_equal(a, b, this.degenerate_face_epsilon) ||
+ this.point_equal(b, c, this.degenerate_face_epsilon) ||
+ this.point_equal(c, a, this.degenerate_face_epsilon);
+ },
go: function() {
// Remove any previous download links
var old_download_link = document.getElementById("nt3d_download");
// Run user_function
this.points = this.user_function.apply(null, params);
+
+ // Do a little validation
if (this.points.length % 3 != 0) {
alert("Points list length not divisble by 3!");
}
- var n = this.points.length / 3;
+ var nan_count = 0;
+ var nan_point_count = 0;
+ var nan_face_count = 0;
+ for (var i = 0; i < this.points.length/3; i++) {
+ var nan_in_face = false;
+ for (var j = 0; j < 3; j++) {
+ var nan_in_point = false;
+ for (var k = 0; k < 3; k++) {
+ if (isNaN(this.points[i*3+j][k])) {
+ nan_count++;
+ nan_in_point = true;
+ nan_in_face = true;
+ }
+ }
+ if (nan_in_point) nan_point_count ++;
+ }
+ if (nan_in_face) nan_face_count ++;
+ }
+ if (nan_count != 0) {
+ alert(nan_count + " NaNs in " + nan_point_count + " points in " + nan_face_count + " faces (" + (100 * nan_face_count / (this.points.length/3)) + "% of faces).");
+ }
+
+ // Remove degenerate faces
+ var degenerate_face_count = 0;
+ for (var i = 0; i < this.points.length/3; i++) {
+ if (this.is_degenerate(this.points[i*3+0],
+ this.points[i*3+1],
+ this.points[i*3+2])) {
+ this.points.splice(i*3, 3);
+ i--;
+ degenerate_face_count ++;
+ }
+ }
+ if (degenerate_face_count != 0) {
+ console.log("Removed " + degenerate_face_count + " degenerate faces");
+ }
// Make STL
this.stl = "solid " + this.user_function.name + "\n";
- for (var i = 0; i < n; i++) {
+ for (var i = 0; i < this.points.length/3; i++) {
var a = this.points[i*3+0];
var b = this.points[i*3+1];
var c = this.points[i*3+2];
projects / nt3d / blobdiff