Hi guys, any idea on how to generate this type of shape in 3D using Lisp ? Idea being that the user would input a few parameters and the 3d shape would generate from those inputs.
I am not looking for this Lisp itself, just some general ideas as to ''how you would go about it'' ....
It's call a Continous Radial Pile or Circular Pile Arragement; used in bulk handling. Both end would need to be rounded as shown on the left hand side of the pile.
Thanks in advance for the ideas !
Two PLINE commands, one UCS command and one EXTRUDE command should do it.
Given a center point [white Point], and either a mid-line radius [inner grey Arc] and a width for the base, or inner and outer radii for the base [for the grey outline], a routine could calculate vertex locations to draw the through-the-quarter-widths magenta Polyline easily enough. Then with a tilt-up UCS based on an end of the center-line Arc, and given a height at the ridge, it could make the yellow triangle with its heel at the center point of one swung end.
Extruding that yellow triangle along that magenta Polyline as a Path gives this:
The quarter-widths route of the Polyline path is what achieves rounding of the ends.
[The grey parts in the first image are for illustration -- they would not need to be drawn as part of the routine, nor would the Point in the middle.]
The inner grey Arc here is 3/4 of a full circle -- presumably an amount of included arc would also be a parameter the User would specify.
I don't know why it didn't occur to me to just use the outline of the base directly, with the tip of the yellow triangle on it, this way:
But for some reason, it says it can't Extrude that triangle in this situation. It's not that it doesn't touch the path -- INTersection Osnap says they touch. I tried it in both the WCS and the triangle's UCS. It's all accurately drawn with good Snap values. I couldn't say why the previous approach works but this doesn't, but as long as something does....
Hi Kent did you rotate3d the triangle ? All done in World.
It could be done as a lisp. RAD1 RAD2 Height.
Here's another way to construct the solid given a closed 2D polyline. Use the Extrude command with the Taper option. It avoids the need to create the triangular cross section.
The following code will create the shape with a taper angle of 25°.
THE TOP VIEW MUST BE ACTIVE WHEN THE COMMAND IS GIVEN!
(defun c:test (/)
; creates a solid with tapered sides from a closed polyline.
(setq ss (ssget))
(setq en (ssname ss 0))
(setq ed (entget en))
(setq p1 (cdr (assoc 10 ed)))
(setq p2 (mapcar '+ p1 '(0 0 0.1)))
(command "_extrude" en "" "T" 25.0 p2 "")
)
