Hello everyone,

hello everyone,

I am trying to rotate a mesh towards the center of the screen so that it 'looks' at the center.  This needs 3 angles to rotate the mesh in a x, y and z direction. The problem is, i dont know how to retrieve those values. At this moment i am in a fight with vectors, and trying to understand the dot and cross product, but with no succes...

to run the sketch, you need the peasycam library and the hemesh library

1. import peasy.*;
   
   import wblut.math.*;
   import wblut.hemesh.modifiers.*;
   import wblut.hemesh.kdtree.*;
   import wblut.hemesh.creators.*;
   import wblut.hemesh.tools.*;
   import wblut.hemesh.*;
   import wblut.hemesh.subdividors.*;
   import wblut.geom.*;
   
   import processing.opengl.*;
   import javax.media.opengl.*;
   // cam
   PeasyCam cam;
   PVector center, angle, child;
   HE_Mesh m; 
   PVector direction = new PVector();
   void setup() {
     size(800,600, OPENGL);
     background(255);
   
     // camera
     cam = new PeasyCam(this, 100);
     cam.setMinimumDistance(1);
     cam.setMaximumDistance(500);
     center = new PVector(0,0,0);
     angle = new PVector(1,0.1,0.3);
     angle.normalize();
     child = new PVector();
   
     child.set(angle);
     child.mult(100);
   
     //angle from child to center
     PVector angleToCenter = new PVector();
     angleToCenter.set(angle);
     angleToCenter.mult(-1);
   
     float d = 10;
     float h = 50;
     float w = 70;
   
     HEC_Creator c = new HEC_Box(this).setDepth(d).setHeight(h).setWidth(w).setWidthSegments(10).setHeightSegments(10).setDepthSegments(10);
     m = new HE_Mesh(c);
   
     double[] limits = m.limits();
     PVector minBoundingBox = new PVector( (float) limits[0], (float) limits[1], (float) limits[2]);
     PVector maxBoundingBox = new PVector( (float) limits[3], (float) limits[4], (float) limits[5]);
   
     float volumeX = calculateDifferences( minBoundingBox.x, maxBoundingBox.x);
     float volumeY = calculateDifferences( minBoundingBox.y, maxBoundingBox.y);
     float volumeZ = calculateDifferences( minBoundingBox.z, maxBoundingBox.z);
   
     int direction_id = 0;
     float[] volumes = {
       volumeX, volumeY, volumeZ
     };
     for(int i = 0; i < volumes.length; i++) {
       if(min(volumes) == volumes[i]) { 
         direction_id = i;
         break;
       }
     }
   
   
     switch(direction_id) {
     case 0:
       direction.set(1,0,0);
       break;
     case 1:
       direction.set(0,1,0);
       break;
     case 2:
       direction.set(0,0,1);
       break;
     }
     direction.mult(30);
     angle.mult(20);
   
     WB_Point rotationCenter = new WB_Point(0,0,0);
     WB_Vector axisDirection = new WB_Vector(1,0,0);
     float rotationAngle = 0;
    
     // horizontal axis = depth rotation
     // m.rotateAboutAxis(rotationAngle, rotationCenter, axisDirection);
   
     axisDirection.set(0,1,0);
     rotationAngle = 0;
     // vertical axis = horizontal rotation
     // m.rotateAboutAxis(rotationAngle, rotationCenter, axisDirection);
   
     axisDirection.set(0,0,1);
     rotationAngle = 0;
     // depth axis = vertial rotation
     // m.rotateAboutAxis(rotationAngle, rotationCenter, axisDirection);
   }
   
   
   void draw() {
     background(255);
     stroke(0);
     strokeWeight(1);
     lights();
     pushMatrix();
     translate(center.x, center.y, center.z);
     box(10);
     strokeWeight(3);
     stroke(255,0,0); 
     beginShape();
     vertex(0,0,0);
     vertex(angle.x, angle.y, angle.z);
     endShape();
     popMatrix();
   
     strokeWeight(1);
     pushMatrix();
     translate(child.x, child.y, child.z);
     stroke(0);
     m.drawFaces();
    
     strokeWeight(3);
     stroke(255,0,0); 
     beginShape();
     vertex(0,0,0);
     vertex(direction.x, direction.y, direction.z);
     endShape();
    
     popMatrix();
   }
   
   

Hello everyone,

Tiny bit by tiny bit i am getting the hang of working with vectors, but i don't know how to fix this one... illustration!



I have a center, from which i create an angle with a random magnitude. From the new point, I want to create a random amount of children, who should "branch" from the original angle, and being distibuted over an ellipse...

really, i don't get this one ..

hopefully someone can help me!
kind regards!

hello everyone,

The Hemesh library is my latest discovery, and I was verrry pleased with its features! I only miss 1 primitive (if you could it like that), and that is the torus (donut/toroid). There is a torus shape in the Shapes3D library, but couldn't find the little algorithm to create it in hemesh...

hopefully someone knows how to create some donuts which can be manipulated!

//

Unfortunately i found no texture options in the library, any d-tour suggestions to accomplish this with the hemeshes?

thanks for any kind of help :)

Hello everybody,

I'm trying to build a hierarchy tree, but i'm having a problem with the following.

The first class is called 'seed', that's were everything starts from.
In there another class is called, 'child_v1'.
The problem is that you can't create a 'child_1' class in a child_1 object... then they are referring to each other and processing doesn't like that!
But it is also stupid to make a 'child_v2' , 'child_v3' etc. class, because then you allready have a pre-described amount of children/layers.... and it should vary from 1/2 untill .... a lot?

hopefully someone can help me with this program problem :) should be a tough cookie for a more experienced person :)