General Program Information

Input Definitions

Inputs Needed to Call the Pipe Function

Origin - a 3*1 matrix with x,y,z positions corresponding to the point where the pipe will be drawn, it correponds to the lower center of the pipe
Pipe_inr - the inner radius of the pipe
Pipe_length - the length of the pipe

Inputs Defined within the Pipe Function

p2 =

• x : origin₀ + outerradius(2*pipe_inr)
• y : origin₁
• z : origin₂

p3 =

• x : origin₀ + pipe_inr
• y : origin₁
• z : origin₂

win1 =

• x : origin₀ - outerradius(2*pipe_inr) - zc
• y : origin₁ - outerradius(2*pipe_inr) - zc
• z : origin₂

win2 =

• x : origin₀ + outerradius(2*pipe_inr) + zc
• y : origin₁ + outerradius(2*pipe_inr) + zc
• z : origin₂

Pipe_outr = outerradius(2*Pipe_inr)

               the outer radius of the pipe, found from the pipe database using the outerradius function

Note: zc corresponds to the zoom constant used within AutoCAD and created in the basics file that is referenced by the pipe program.

Technical Program Outline

Note: All coordinates are referenced in top view in the program unless otherwise specified

zoom_win- zooms on a window space directly around where the pipe is to be draw (as shown above - actual window size relative to pipe that is to be drawn).  The points win1 and win2 are used to select this window size, based on including the space of the pipe (the outer radius) and a zoom constant (zc) to ensure the entire drawing will be within the frame.

zoom_win <-- zoom_win(win1,win2)

win1 =

• x : origin₀ - outerradius(2*pipe_inr) - zc
• y : origin₁ - outerradius(2*pipe_inr) - zc
• z : origin₂

win2 =

• x : origin₀ + outerradius(2*pipe_inr) + zc
• y : origin₁ + outerradius(2*pipe_inr) + zc
• z : origin₂

cylinder1 - Draws the larger of the two cylinders needed to create a pipe. The cylinder has pipe_outr as the radius. From topview, the cylinder draws up towards the viewer with the pipe origin at the bottom base.

cylinder1 <-- cylinder(origin,pipe_outr,pipe_length)

origin =

• x : origin₀
• y : origin₁
• z : origin₂

pipe_outr = outerradius(2*pipe_inr)

pipe_length = pipe_length

cylinder2 - Draws the smaller of the two cylinders needed to create the pipe. The cylinder has pipe_inr as the radius. From topview, the cylinder draws up towards the viewer with the pipe origin at the bottom base. This inner cylinder will then be subtracted to create the hollow pipe, with the inner radius as specified.

cylinder2 <-- cylinder(origin,pipe_inr,pipe_length)

origin =

• x : origin₀
• y : origin₁
• z : origin₂

pipe_inr : pipe_inr

pipe_length : pipe_length

subtract1 - In order to create the hollow pipe, the inner cylinder must be subtracted from the outer cylinder. The subtract function selects p2, on the edge of the inner cylinder, to select the inner cylinder as the piece to be subtracted. The subtract function then selects p3, on the edge of the outer cylinder, to select the outer cylinder to subtract from.

subtract <-- subtract(p2,p3)

p2 =

• x : origin₀ + pipe_inr
• y : origin₁
• z : origin₂

p3 =

• x : origin₀ + outerradius(2*pipe_inr)
• y : origin₁
• z : origin₂