public Triangle(Mesh owner, int index0, int index1, int index2, Material material) {
this.owner = owner;
index = new int[3];
index[0] = index0;
index[1] = index1;
index[2] = index2;
Point3 v0 = owner.getVertex(index0);
Point3 v1 = owner.getVertex(index1);
Point3 v2 = owner.getVertex(index2);
if (!owner.existsNormals()) {
Vector3 e0 = new Vector3(), e1 = new Vector3();
e0.sub(v1, v0);
e1.sub(v2, v0);
norm = new Vector3();
norm.cross(e0, e1);
}
a = v0.x - v1.x;
b = v0.y - v1.y;
c = v0.z - v1.z;
d = v0.x - v2.x;
e = v0.y - v2.y;
f = v0.z - v2.z;
this.setMaterial(material);
}
public void updateArea() {
Vector3 u = new Vector3(), v = new Vector3(), n = new Vector3();
u.set(
mesh.verts[3 * v1] - mesh.verts[3 * v0],
mesh.verts[3 * v1 + 1] - mesh.verts[3 * v0 + 1],
mesh.verts[3 * v1 + 2] - mesh.verts[3 * v0 + 2]);
v.set(
mesh.verts[3 * v2] - mesh.verts[3 * v0],
mesh.verts[3 * v2 + 1] - mesh.verts[3 * v0 + 1],
mesh.verts[3 * v2 + 2] - mesh.verts[3 * v0 + 2]);
n.cross(u, v);
area = 0.5 * n.length();
oneOverArea = 1. / area;
}