Through the Interface

// Use lightweight F# syntax

#light

// Declare a specific namespace and module name

module MyNamespaceRecursive.MyApplication

// Import managed assemblies

#I @"C:\Program Files\Autodesk\AutoCAD 2008"

#r "acdbmgd.dll"

#r "acmgd.dll"

open Autodesk.AutoCAD.Runtime

open Autodesk.AutoCAD.ApplicationServices

open Autodesk.AutoCAD.DatabaseServices

open Autodesk.AutoCAD.Geometry

// Get a random vector on a plane

let randomVectorOnPlane pl =

  // Create our random number generator

  let ran = new System.Random()

  // First we get the absolute value

  // of our x, y and z coordinates

  let absx = ran.NextDouble()

  let absy = ran.NextDouble()

  // Then we negate them, half of the time

  let x = if (ran.NextDouble() < 0.5) then -absx else absx

  let y = if (ran.NextDouble() < 0.5) then -absy else absy

  let v2 = new Vector2d(x,y)

  new Vector3d(pl,v2)

// Get a random vector in 3D space

// Note: _ is only used to make sure this function gets

// executed when it is called... if we have no argument

// it's a value that doesn't require repeated execution

let randomVector3d _ =

  // Create our random number generator

  let ran = new System.Random()

  // First we get the absolute value

  // of our x, y and z coordinates

  let absx = ran.NextDouble()

  let absy = ran.NextDouble()

  let absz = ran.NextDouble()

  // Then we negate them, half of the time

  let x = if (ran.NextDouble() < 0.5) then -absx else absx

  let y = if (ran.NextDouble() < 0.5) then -absy else absy

  let z = if (ran.NextDouble() < 0.5) then -absz else absz

  new Vector3d(x, y, z)

// Now we declare our command

[<CommandMethod("ptsr")>]

let createPoints () =

  // Let's get the usual helpful AutoCAD objects

  let doc =

    Application.DocumentManager.MdiActiveDocument

  let ed = doc.Editor

  let db = doc.Database

  // "use" has the same effect as "using" in C#

  use tr =

    db.TransactionManager.StartTransaction();

  // Get appropriately-typed BlockTable and BTRs

  let bt =

    tr.GetObject

      (db.BlockTableId,OpenMode.ForRead)

    :?> BlockTable

  let ms =

    tr.GetObject

      (bt.[BlockTableRecord.ModelSpace],

      OpenMode.ForRead)

    :?> BlockTableRecord

  // A function that accepts an ObjectId and returns

  // a list of random points on its surface

  let rec getNPoints n (sol:Solid3d) ptlist =

    if n <= 0 then

      ptlist

    else

      let mp = sol.MassProperties

      let pl = new Plane()

      pl.Set(mp.Centroid,randomVector3d n)

      let reg = sol.GetSection(pl)

      let ray = new Ray()

      ray.BasePoint <- mp.Centroid

      ray.UnitDir <- randomVectorOnPlane pl

      let pts = new Point3dCollection()

      reg.IntersectWith

        (ray,

        Intersect.OnBothOperands,

        pts,

        0, 0)

      pl.Dispose()

      reg.Dispose()

      ray.Dispose()

      getNPoints

        (n - pts.Count) sol

        (ptlist @ Seq.untyped_to_list pts)

  let generatePoints numPoints (x : ObjectId) =

    let obj = tr.GetObject(x,OpenMode.ForRead)

    match obj with

    | 😕 Solid3d ->

      let sol = (obj :?> Solid3d)

      getNPoints numPoints sol []

    | _ -> []

  // A recursive function to show the contents of a list

  let rec drawPointList (x:Point3d list) =

    match x with

    | [] -> ()

    | h :: t ->

      ed.DrawVector(h,h,1,true)

      drawPointList t

  // Let's generate 100K points per solid

  let points = generatePoints 100000

  // Here's where we plug everything together...

  Seq.untyped_to_list ms |> // ObjectIds from modelspace

    List.map points |>      // Get points for each object

      List.concat |>        // No need for the outer list

        drawPointList       // Draw the resultant points

  // As usual, committing is cheaper than aborting

  tr.Commit()