How can I draw an Arc using MeshGeometry3D in WPF c#? - wpf

Question

I want to draw Arc in Vieport3D using MeshGeometry3D.I have searched for it a lot but not found anything ,what I found is using PathGeometry.I am new to WPF so don't know much about 3D graphics.How can I do this?
thanks

Answer 1

here is the code which I wrote to create mesh-geometry for Arc.I hope this will help someone.
private GeometryModel3D GetModel(double radius, Vector3D normal, Point3D center, int resolution, double StartAngle, double EndAngle)
{
var mod = new GeometryModel3D();
var geo = new MeshGeometry3D();
// Generate the circle in the XZ-plane
// Add the center first
geo.Positions.Add(new Point3D(0, 0, 0));
// Iterate from angle 0 to 2*PI
double dev = (2 * Math.PI) / resolution;
double thik = 0.02;
//float spaceangle = StartAngle + 1;
if (StartAngle != EndAngle)
{
for (double i = StartAngle; i < EndAngle; i += dev)
{
geo.Positions.Add(new Point3D(radius * Math.Cos(i), 0, -radius * Math.Sin(i)));
geo.Positions.Add(new Point3D((radius-thik) * Math.Cos(i), 0, (-(radius-thik)) * Math.Sin(i)));
}
for (int i = 3; i < geo.Positions.Count; i += 1)
{
geo.TriangleIndices.Add(i - 3);
geo.TriangleIndices.Add(i - 1);
geo.TriangleIndices.Add(i - 2);
geo.TriangleIndices.Add(i - 1);
geo.TriangleIndices.Add(i);
geo.TriangleIndices.Add(i - 2);
}
}
mod.Geometry = geo;
// Create transforms
var trn = new Transform3DGroup();
// Up Vector (normal for XZ-plane)
var up = new Vector3D(0, 1, 0);
// Set normal length to 1
normal.Normalize();
var axis = Vector3D.CrossProduct(up, normal); // Cross product is rotation axis
var angle = Vector3D.AngleBetween(up, normal); // Angle to rotate
trn.Children.Add(new RotateTransform3D(new AxisAngleRotation3D(axis, angle)));
trn.Children.Add(new TranslateTransform3D(new Vector3D(center.X, center.Y, center.Z)));
mod.Transform = trn;
return mod;
}