Skip to content

Cylinder.md

Latest commit

 

History

History
99 lines (78 loc) · 3.27 KB

Cylinder.md

File metadata and controls

99 lines (78 loc) · 3.27 KB

Cylinder Class

Overview

The Cylinder class represents a bounded right circular cylinder surface in 3D space. Cylinders are common 3D primitives used in mechanical design and modeling.

Namespace

Autodesk.AutoCAD.Geometry

Key Properties

Property Type Description
Origin Point3d Gets the base point of the cylinder
AxisOfSymmetry Vector3d Gets the rotation axis vector
Radius double Gets the radius of the cylinder base
Height double Gets the height of the cylinder
ReferenceAxis Vector3d Gets reference vector on base circle
IsOuterNormal bool Indicates if surface normal points outward

Key Methods

Method Return Type Description
GetClosestPointTo(Point3d) Point3d Gets closest point on cylinder surface
DistanceTo(Point3d) double Gets distance from point to surface
IsOn(Point3d) bool Checks if point is on surface

Code Examples

Example 1: Creating Cylinders

// Cylinder with base at origin, axis along Z, radius 5, height 10
Point3d baseCenter = Point3d.Origin;
Vector3d axis = Vector3d.ZAxis;
double radius = 5.0;
double height = 10.0;

Cylinder cylinder = new Cylinder(baseCenter, axis, radius, height);

ed.WriteMessage($"\nCylinder created");
ed.WriteMessage($"\nBase: {cylinder.Origin}");
ed.WriteMessage($"\nAxis: {cylinder.AxisOfSymmetry}");
ed.WriteMessage($"\nRadius: {cylinder.Radius}");
ed.WriteMessage($"\nHeight: {cylinder.Height}");

Example 2: Cylinder Calculations

Cylinder cyl = new Cylinder(Point3d.Origin, Vector3d.ZAxis, 5.0, 10.0);

double lateralArea = 2 * Math.PI * cyl.Radius * cyl.Height;
double baseArea = Math.PI * Math.Pow(cyl.Radius, 2);
double totalSurfaceArea = lateralArea + 2 * baseArea;
double volume = baseArea * cyl.Height;

ed.WriteMessage($"\nLateral surface area: {lateralArea:F2}");
ed.WriteMessage($"\nTotal surface area: {totalSurfaceArea:F2}");
ed.WriteMessage($"\nVolume: {volume:F2}");

Example 3: Horizontal Cylinder

// Cylinder along X axis
Point3d baseCenter = new Point3d(0, 5, 5);
Vector3d axis = Vector3d.XAxis; // Horizontal
double radius = 3.0;
double height = 15.0;

Cylinder horizontalCyl = new Cylinder(baseCenter, axis, radius, height);

Point3d topCenter = new Point3d(
    baseCenter.X + height * axis.X,
    baseCenter.Y + height * axis.Y,
    baseCenter.Z + height * axis.Z
);

ed.WriteMessage($"\nHorizontal cylinder");
ed.WriteMessage($"\nBase center: {baseCenter}");
ed.WriteMessage($"\nTop center: {topCenter}");

Best Practices

  1. Axis: Axis vector should be normalized (unit vector)
  2. Height: Measured along axis from base
  3. Orientation: Base is at origin point, top is origin + height * axis
  4. Surface Area: Lateral = 2πrh, Total = 2πr(r + h)
  5. Volume: V = πr²h

Related Classes

  • Sphere - Spherical surface
  • Cone - Conical surface
  • Torus - Toroidal surface
  • Point3d - Base center
  • Vector3d - Axis direction

References