Simple way to create a 3D mesh from a set of points?

leducmills

Simple way to create a 3D mesh from a set of points?

in Contributed Library Questions • 2 years ago

My problem is that I'm dealing with a dynamically changing set of points, anywhere from 0 to 64 (they correspond to coordinates from switches coming in serially from arduino) - I adapted the quickhull3d library that the Mesh lib is based on - and it works great as long as the points form a shape with a convex hull (not colinear, coincident, or coplanar) - otherwise it throws an illegal argument exception that crashes the sketch.

So, I'm wondering if there's a way to create a 3d mesh that can gracefully degrade into lines or 2d planes, or if someone can give me some pointers as to how to change the illegal argument exceptions in Java into something I can write a check method to that won't crash the program. I looked at toxiclibs, but I didn't see a way to get a mesh just through an array of points (without having faces or triangles first).

Here's version of the code that doesn't use serial input, I just use to test the software:

/* UCube v.0x2
* 3d modeling input device and stl export
* No Serial communication, used for software feature building
* by Ben Leduc-Mills
*/
import controlP5.*;
import unlekker.util.*;
import unlekker.geom.*;
import unlekker.data.*;
import ec.util.*;
import quickhull3d.*;
//import processing.serial.*;
//Serial myPort; // the serial port
ControlP5 controlP5;
PFont myFont; //init font for text
STL stl; //init STL object
FaceList poly; //FaceList object for .stl import
QuickHull3D hull = new QuickHull3D(); //init quickhull
Point3d[] points; //init Point3d array
float rotX, rotY; //for manual roatation
int gridSize = 4; //size of grid (assumes all dimensions are equal)
int spacing = 50; //distance between points
int counter = 0; //wireframe toggle
String inString; //string of coordinates from arduino
void setup() {
// String[] fontList = PFont.list();
// println(fontList);
controlP5 = new ControlP5(this);
controlP5.addButton("Refresh",0,100,100,80,19);
controlP5.addButton("Mode", 0,100,120,80,19);
controlP5.addButton("Export", 0,100,140,80,19);
controlP5.addButton("Import", 0,100,160,80,19);
myFont = createFont("FFScala", 32);
textFont(myFont);
size(1000, 750, P3D);
// println(Serial.list()); // list available serial ports
// myPort = new Serial(this, Serial.list()[0], 9600);
// myPort.bufferUntil(' ');
background(255); //set initial background color (just looks nicer on startup)
genPoints(); //generate random set of points
}
void draw() {
background(250);
pushMatrix();
translations();
drawGrid();
drawAxes();
//inString = "0,0,0;0,0,2;0,2,0;0,2,2;2,0,0;2,0,2;2,2,2;2,2,0;"; //cube
//inString = "0,0,0;0,1,0;0,2,0;0,3,0;"; //straight line
if (poly != null) {
drawImport();
//poly.draw(this);
}
if (inString != null) {
//make acive points more visible
strokeWeight(8);
stroke(255, 0, 0);
//trim whitespace
inString = trim(inString);
//split string of mutliple coordinates into coordinate-sized chuncks
String coord[] = split(inString, ';');
//init point3d array equal to number of activated points
points = new Point3d[coord.length-1];
//put the xyz coordinates into the point3d array and draw them
for(int p3d = 0; p3d < coord.length-1; p3d++) {
int subCoord[] = int(split(coord[p3d], ','));
points[p3d] = new Point3d(subCoord[0] * spacing, subCoord[1] * spacing, subCoord[2] * spacing);
point(subCoord[0] * spacing, subCoord[1] * spacing, subCoord[2] * spacing);
}
if (counter%2 != 0) {
showShape();
}
} //end if inString!=null
popMatrix();
} //end draw
public void controlEvent(ControlEvent theEvent) {
println(theEvent.controller().name());
}
void mouseDragged() {
float x1 = mouseX-pmouseX;
float y1 = mouseY-pmouseY;
rotX = (mouseY * -0.01);
rotY = (mouseX * 0.01);
}
void translations() {
translate(width/2, height/2);
rotateX(rotX);
rotateY(rotY);
}
void drawGrid() {
//draw rest of grid
//(spacing * (gridSize -1) * -1) /2 = center around 0
int xpos = 0;
int ypos = 0;
int zpos = 0;
for (int i = 0; i < gridSize; i++) {
for (int j = 0; j < gridSize; j++) {
for( int k = 0; k < gridSize; k++) {
stroke(100);
strokeWeight(2);
point(xpos, ypos, zpos);
//println(xpos + "," + ypos + "," + zpos);
xpos += spacing;
}
xpos = 0;
ypos += spacing;
}
xpos = 0;
ypos = 0;
zpos += spacing;
}
}
void drawAxes() {
stroke(255,0,255);
line(0,0,0, 100,0,0);
fill(255,0,255);
text("X", 200, 0);
stroke(0,255,0);
line(0,0,0, 0,-100,0);
fill(0,255,0);
text("Y", 0, -200);
stroke(0,0,255);
line(0,0,0, 0,0,100);
fill(0,0, 255);
text("Z", 0, 0, 200);
fill(0,0,0);
}
public void Import (int theValue) {
importSTL();
}
public void importSTL() {
String loadPath = selectInput(); // Opens file chooser
if (loadPath == null) {
// If a file was not selected
println("No file was selected...");
}
else {
inString = null;
// If a file was selected, print path to file
println(loadPath);
stl = new STL(this, loadPath);
poly = stl.getPolyData();
int faces = poly.num;
if (poly != null) {
//poly.normalize(150);
//poly.calcBounds();
//poly.center();
for( int i = 0; i < faces; i++) {
poly.f[i].translate(width/2,height/2,650);
}
}
}
}
public void drawImport() {
beginShape(TRIANGLE_STRIP);
stroke(255,0,0);
strokeWeight(1);
int offset = 0;
for (int i = 0; i < poly.f.length; i++) {
//println(poly.f[i]);
vertex(poly.f[i].v[3] + offset, poly.f[i].v[4] + offset, poly.f[i].v[5] + offset);
vertex(poly.f[i].v[6] + offset, poly.f[i].v[7] + offset, poly.f[i].v[8] + offset);
vertex(poly.f[i].v[9] + offset, poly.f[i].v[10] + offset, poly.f[i].v[11] + offset);
}
endShape(CLOSE);
}
public void Export(int theValue) {
outputSTL();
}
void outputSTL() {
//function to output STL file
//make sure we have at least 4 points or an imported stl
//(can't have a 3d shape with less)
if(poly != null) { //we have an import
stl=(STL)beginRaw("unlekker.data.STL", selectOutput());
beginShape(TRIANGLE_STRIP);
for (int i = 0; i < poly.f.length; i++) {
//println(poly.f[i]);
vertex(poly.f[i].v[3], poly.f[i].v[4], poly.f[i].v[5]);
vertex(poly.f[i].v[6], poly.f[i].v[7], poly.f[i].v[8]);
vertex(poly.f[i].v[9], poly.f[i].v[10], poly.f[i].v[11]);
}
endShape(CLOSE);
endRaw();
}
else if (points.length > 3) {
//compute the convex hull
hull.build(points);
//get an array of the vertices so we can get the faces
Point3d[] vertices = hull.getVertices();
//start writing the stl file - file should appear in your sketch folder
//stl=(STL)beginRaw("unlekker.data.STL","convexhull" + month() + day() + "-" + second()+ millis() + ".stl");
stl=(STL)beginRaw("unlekker.data.STL", selectOutput());
//different beginShape() modes may affect the shape produced
beginShape(TRIANGLE_STRIP);
fill(255);
int[][] faceIndices = hull.getFaces();
for (int i = 0; i < faceIndices.length; i++) {
for (int k = 0; k < faceIndices[i].length; k++) {
//get points that correspond to each face
Point3d pnt2 = vertices[faceIndices[i][k]];
float x = (float)pnt2.x;
float y = (float)pnt2.y;
float z = (float)pnt2.z;
vertex(x,y,z);
//println(x + "," + y + "," + z);
}
}
endShape(CLOSE);
endRaw();
}
}
public void Mode(int theValue) {
counter++;
println(counter);
showShape();
}
public void showShape() {
//brute force inefficiency
beginShape(TRIANGLE_STRIP);
strokeWeight(1);
fill(0);
int numPoints = points.length;
for (int j = 0; j < 4800; j++) {
int i = int(random(0,numPoints));
float x = (float)points[i].x;
float y = (float)points[i].y;
float z = (float)points[i].z;
vertex(x,y,z);
}
endShape(CLOSE);
}
public void Refresh (int theValue) {
genPoints();
if (poly != null) {
poly = null;
}
}
public void genPoints() {
//setup1
String c000 = "0,0,0;";
String c010 = "0,1,0;";
String c020 = "0,2,0;";
String c030 = "0,3,0;";
//setup2
String c001 = "0,0,1;";
String c011 = "0,1,1;";
String c021 = "0,2,1;";
String c031 = "0,3,1;";
//setup3
String c002 = "0,0,2;";
String c012 = "0,1,2;";
String c022 = "0,2,2;";
String c032 = "0,3,2;";
//setup4
String c003 = "0,0,3;";
String c013 = "0,1,3;";
String c023 = "0,2,3;";
String c033 = "0,3,3;";
//setup5
String c100 = "1,0,0;";
String c110 = "1,1,0;";
String c120 = "1,2,0;";
String c130 = "1,3,0;";
//setup6
String c101 = "1,0,1;";
String c111 = "1,1,1;";
String c121 = "1,2,1;";
String c131 = "1,3,1;";
//setup7
String c102 = "1,0,2;";
String c112 = "1,1,2;";
String c122 = "1,2,2;";
String c132 = "1,3,2;";
//setup8
String c103 = "1,0,3;";
String c113 = "1,1,3;";
String c123 = "1,2,3;";
String c133 = "1,3,3;";
//setup9
String c200 = "2,0,0;";
String c210 = "2,1,0;";
String c220 = "2,2,0;";
String c230 = "2,3,0;";
//setup10
String c201 = "2,0,1;";
String c211 = "2,1,1;";
String c221 = "2,2,1;";
String c231 = "2,3,1;";
//setup11
String c202 = "2,0,2;";
String c212 = "2,1,2;";
String c222 = "2,2,2;";
String c232 = "2,3,2;";
//setup12
String c203 = "2,0,3;";
String c213 = "2,1,3;";
String c223 = "2,2,3;";
String c233 = "2,3,3;";
//setup13
String c300 = "3,0,0;";
String c310 = "3,1,0;";
String c320 = "3,2,0;";
String c330 = "3,3,0;";
//setup14
String c301 = "3,0,1;";
String c311 = "3,1,1;";
String c321 = "3,2,1;";
String c331 = "3,3,1;";
//setup15
String c302 = "3,0,2;";
String c312 = "3,1,2;";
String c322 = "3,2,2;";
String c332 = "3,3,2;";
//setup16
String c303 = "3,0,3;";
String c313 = "3,1,3;";
String c323 = "3,2,3;";
String c333 = "3,3,3;";
String coord[] = {
c000, c010, c020, c030, //setup1
c001, c011, c021, c031, //setup2
c002, c012, c022, c032, //setup3
c003, c013, c023, c033, //setup4
c100, c110, c120, c130, //setup5
c101, c111, c121, c131, //setup6
c102, c112, c122, c132, //setup7
c103, c113, c123, c133, //setup8
c200, c210, c220, c230, //setup9
c201, c211, c221, c231, //setup10
c202, c212, c222, c232, //setup11
c203, c213, c223, c233, //setup12
c300, c310, c320, c330, //setup13
c301, c311, c321, c331, //setup14
c302, c312, c322, c332, //setup15
c303, c313, c323, c333 //setup16
};
int numCoords = int(random(1,32));
String[] c = new String[numCoords];
for (int i = 0; i < numCoords; i++) {
c[i] = coord[int(random(64))];
}
inString = join(c, "");
}

Thanks in advance for any suggestions.

-b

Replies(1)

leducmills

Re: Simple way to create a 3D mesh from a set of points?

2 years ago

Sorry, if you want to run the code, you'll need the adapted version of the quickhull library, which you can find here: http://benatwork.cc/wp-content/uploads/2010/10/quickhull3d.zip

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