// a function for displaying the normals in an STL file
public static void draw_stl_normals(GLWindow g, STLSurf s)
{
// draw triangle normas
foreach (Geo.Tri t in s.tris)
{
// from STL file
Geo.Point p1 = new Geo.Point(t.p[0].x, t.p[0].y, t.p[0].z);
Geo.Point p2 = new Geo.Point(t.p[0].x + t.n.x, t.p[0].y + t.n.y, t.p[0].z + t.n.z);
GeoLine l = new GeoLine(p1, p2);
l.color = System.Drawing.Color.Green;
g.addGeom(l);
// calculate yourself:
Vector v1 = new Vector(t.p[0].x - t.p[1].x, t.p[0].y - t.p[1].y, t.p[0].z - t.p[1].z);
Vector v2 = new Vector(t.p[0].x - t.p[2].x, t.p[0].y - t.p[2].y, t.p[0].z - t.p[2].z);
Vector n;
n = v1.Cross(v2); // the normal is in the direction of the cross product between the edge vectors
n = (1 / n.Length()) * n; // normalize to length==1
p1 = new Geo.Point(t.p[0].x, t.p[0].y, t.p[0].z);
p2 = new Geo.Point(t.p[0].x + n.x, t.p[0].y + n.y, t.p[0].z + n.z);
l = new GeoLine(p1, p2);
l.color = System.Drawing.Color.Blue;
g.addGeom(l);
}
}
public void recalc_normals()
{
// normal data from STL files is usually junk, so recalculate:
Vector v1 = new Vector(p[0].x - p[1].x, p[0].y - p[1].y, p[0].z - p[1].z);
Vector v2 = new Vector(p[0].x - p[2].x, p[0].y - p[2].y, p[0].z - p[2].z);
n = v1.Cross(v2); // the normal is in the direction of the cross product between the edge vectors
n = (1 / n.Length()) * n; // normalize to length==1
}
public void pan_lr(double amount)
{
// move cen to the left
Vector v = up.Cross(eye - cen);
v.normalize();
amount = 0.001 * amount * _r;
cen.x += amount * v.x;
cen.y += amount * v.y;
cen.z += amount * v.z;
recalc();
}
public Tri(Point P1, Point P2, Point P3)
{
p = new Point[3];
bb = new Bbox();
p[0] = P1;
p[1] = P2;
p[2] = P3;
// if normal is not given, calculate it here.
Vector v1 = new Vector(p[0].x - p[1].x, p[0].y - p[1].y, p[0].z - p[1].z);
Vector v2 = new Vector(p[0].x - p[2].x, p[0].y - p[2].y, p[0].z - p[2].z);
n = v1.Cross(v2); // the normal is in the direction of the cross product between the edge vectors
n = (1 / n.Length()) * n; // normalize to length==1
}
private void recalc()
{
// recalculate eye position
eye.x = cen.x + _r * Math.Cos(_theta) * Math.Sin(_fi);
eye.y = cen.y + _r * Math.Sin(_theta) * Math.Sin(_fi);
eye.z = cen.z + _r * Math.Cos(_fi);
// recalculate up-vector
Vector n = new Vector(Math.Sin(_theta), -Math.Cos(_theta), 0);
up = n.Cross(eye - cen);
up.normalize();
// System.Console.WriteLine("Camera: cen=" + cen + " eye=" + eye);
}
public void recalc_normals()
{
// normal data from STL files is usually junk, so recalculate:
Vector v1 = new Vector(p[0].x - p[1].x, p[0].y - p[1].y, p[0].z - p[1].z);
Vector v2 = new Vector(p[0].x - p[2].x, p[0].y - p[2].y, p[0].z- p[2].z);
n = v1.Cross(v2); // the normal is in the direction of the cross product between the edge vectors
n = (1 / n.Length()) * n; // normalize to length==1
}
public Tri(Point P1, Point P2, Point P3)
{
p = new Point[3];
bb = new Bbox();
p[0] = P1;
p[1] = P2;
p[2] = P3;
// if normal is not given, calculate it here.
Vector v1 = new Vector(p[0].x - p[1].x, p[0].y - p[1].y, p[0].z - p[1].z);
Vector v2 = new Vector(p[0].x - p[2].x, p[0].y - p[2].y, p[0].z- p[2].z);
n = v1.Cross(v2); // the normal is in the direction of the cross product between the edge vectors
n = (1 / n.Length()) * n; // normalize to length==1
}
