TUBE_A

TUBE_A generates a tubular surface by displacement of a polylined contour along a spatial polyline (= path curve). In each joint of the path curve the polylined contour is situated in the bisector plane of the projections of the joint segments to the local XY plane; the cross-section is identical with the polylined contour at the beginning of the displacement (the coordinates u1, w1, ... , un, wn remain unchanged). Arcs and segments can be defined within the polyline by using additional status code values.

Syntax

TUBE_A n, m, mask, u1, w1, s1, ... , un, wn, sn, x1, y1, z1, ... , xm, ym, zm

Parameters

n (integer): number of polyline nodes

m (integer): number of path curve nodes

mask: controls the existence of the surfaces at the beginning and the end of the tube (see below)

ui, wi: U and W coordinates of the base polyline nodes in the UW coordinate system

si (boolean): controls the appearance of the lateral edges; if si = 0 the line segment between ni and ji will not be drawn, if si = 1 this line segment will be drawn

xi, yi, zi: X, Y and Z coordinates of the path curve nodes

Important: The path curve comprises two nodes more than the number of generated sections. The first and the last node determine the position in space of the first and the last surface belonging to the tube. These nodes are relevant solely for determining the normal of the surfaces, they are no actual nodes of the path curve. The orientation of the surfaces is the same as that of the surfaces that would be generated at the nodes nearest to the two endpoints, if the tube was continued in the directions indicated by these.

parameter restrictions: n > 2, m > 3

Masking

mask = j1 + 2*j2

with j1, j2 may be 0 or 1
j1 (1): surface at the beginning of the tube is present
j2 (2): surface at the end of the tube is present

Remarks

In contrast to TUBE the polylined contour in the middle of each path segment may be different from the polylined contour at the beginning of the displacement; furthermore the polylined contour must not be closed: in this case the section polygons will be generated to reach the local XY plane as in the case of REVOLVE surfaces.

Usable since script version 1.1 (Allplan 2012-1).