org.jcae.opencascade/src-java-test/org/jcae/opencascade/jni/Curvature.java

   1 package org.jcae.opencascade.jni;
   2
   3 import static org.junit.Assert.*;
   4 import org.junit.Test;
   5
   6 public class Curvature
   7 {
   8         /** Example to show how to get the curvature of a surface */
   9         @Test public void sample()
  10         {
  11                 //Create an cone for the example
  12                 double[] axis=new double[]{
  13                         0, 0, 0,
  14                         1, 2, 3
  15                 };
  16                 TopoDS_Shape shape=new BRepPrimAPI_MakeCone(
  17                         axis, 3, 1, 4, Math.PI*2).shape();
  18
  19                 // Select the side of the cone
  20                 TopExp_Explorer exp=new TopExp_Explorer(shape, TopAbs_ShapeEnum.FACE);
  21                 TopoDS_Face face=(TopoDS_Face) exp.current();
  22
  23                 // Get the geometry associated to the previously selected face
  24                 Geom_Surface geom = BRep_Tool.surface(face);
  25
  26                 // Get parameters intervals
  27                 double[] paramBounds=new double[4];
  28                 geom.bounds(paramBounds);
  29                 double umin=paramBounds[0];
  30                 double umax=paramBounds[1];
  31                 double vmin=paramBounds[2];
  32                 double vmax=paramBounds[3];
  33
  34                 // Handle the case of infinite geometry
  35                 if(!geom.isUClosed())
  36                 {
  37                         umin=0;
  38                         umax=1;
  39                 }
  40
  41                 if(!geom.isVClosed())
  42                 {
  43                         vmin=0;
  44                         vmax=1;
  45                 }
  46
  47                 // Create the object which allow to ask for various local geometry
  48                 // properties
  49                 GeomLProp_SLProps props=new GeomLProp_SLProps(2, 1E-7);
  50                 props.setSurface(geom);
  51
  52
  53                 // Iterate on u and v and display various properties at each point
  54                 double ustep=(umax-umin)/10;
  55                 double vstep=(vmax-vmin)/10;
  56
  57                 for(double u=umin; u<umax; u+=ustep)
  58                 {
  59                         for(double v=vmin; v<vmax; v+=vstep)
  60                         {
  61                                 props.setParameters(u, v);
  62                                 //The 3D coordinate associated to the u,v coordinate
  63                                 double[] p = props.value();
  64                                 //The first derivative allong U
  65                                 double[] d1u = props.d1U();
  66                                 //The second derivative allong U
  67                                 double[] d2u = props.d2U();
  68
  69                                 System.out.println("M: ("+p[0]+", "+p[1]+", "+p[2]+")");
  70                                 System.out.println("dM/dU: ("+d1u[0]+", "+d1u[1]+", "+d1u[2]+")");
  71                                 System.out.println("d2M/d2U: ("+d2u[0]+", "+d2u[1]+", "+d2u[2]+")");
  72                         }
  73                 }
  74         }
  75 }
  76