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Next: GEOMETRY LINE NODES [lnam] pnam1 pnam2 Up: GEOMETRY LINE Control Previous: GEOMETRY LINE ELEMENTS lnam [elty]

GEOMETRY LINE INTERSECT [lnam] shp1 shp2 [[+/-/ ] shpn...] [divn]
or: ... [lnam] pnm1 pnm2 pnm3 shp1 shp2 [divn]

          

The two forms of this command allow intersection lines to be created from FEMGEN analytical shapes either directly or by using existing FEMGEN points to define the extent of the intersection curve.


lnam = name of the first line that is created, used for later references to the line.
shp1, shp2 = names of two analytical shapes (ie plane, cylinder, cone or sphere) on which
the intersection line(s) will lie.
shpn = names of additional shapes used to limit the extent of the intersection line.
If no additonal shapes are given then the full intersection curve between the
two shapes is generated and divided into a suitable number of FEMGEN
lines.
pnm1 = name of a point which defines the start point of the line.
pnm2 = name of a point which defines the end point of the line.
pnm3 = name of a point which specifies which of the two possible curves that is
intended. The point need not lie on the curve but should be near the middle
of the curve.
divn = integer which specifies how many nodes are to be placed along the line. If
omitted a default of four divisions (ie Five nodes) is assumed. The default
number of divisions can be reset using the command
MESHING DIVISION DEFAULT.

With the first form of this command it is possible to use additional shapes to control the extent of the intersection that is created by using the '+' character to select the positive side of a plane or inside of any other shape and '-' to select the negative side of a plane or the outside of any other shape (except for a box shape). If '+/-' is not specified then points on the intersection line are created where the additional shape(s) meet the two main shapes.

Return Level: GEOMETRY LINE

Examples:

1.
GEOMETRY LINE INTERSECT CYL1 CYL2

Create a series of intersection lines which lie on the intersection curve between shapes CYL1 and CYL2. Note that both the possible intersections are considered.

 
Figure 2.75: Definition of intersection lines directly from two shapes
\begin{figure} \centerline{ \psfig {figure=diagrams/newint1.eps,width=2.0in} }\end{figure}

2.
GEOMETRY LINE INTERSECT CYL1 CYL2 +PLY0

Create a series of intersection lines which lie on the intersection curve between shapes CYL1 and CYL2 and are on the positive side of the plane PLY0.


 
Figure 2.76: Definition of intersection lines directly from two shapes and one additional shape
\begin{figure} \centerline{ \psfig {figure=diagrams/newint2.eps,width=2.0in} }\end{figure}

3.
GEOMETRY LINE INTERSECT CYL1 CYL2 +PLY0 +PLZ0

Create a series of intersection lines which lie on the intersection curve between shapes CYL1 and CYL2 and are on the positive side of the plane PLY0 and the plane PLZ0.


 
Figure 2.77: Definition of intersection lines directly from two shapes and two additional shapes
\begin{figure} \centerline{ \psfig {figure=diagrams/newint5.eps,width=2.0in} }\end{figure}

4.
GEOMETRY LINE INTERSECT LC1 P1 P2 P3 SH1 SH2

Create a line LC1 with start point P1, end point P2, which lies on the intersection curve between shapes SH1 and SH2 which is nearest to point P3, with the default number of divisions.


 
Figure 2.78: Definition of an intersection line from three points and two shapes
\begin{figure} \centerline{ \psfig {figure=diagrams/lineint.ps,width=2.0in} }\end{figure}

See also the following commands

'LABEL GEOMETRY LINES'
'UTILITY DELETE LINES'
'UTILITY TABULATE GEOMETRY LINES'
'VIEW GEOMETRY'

next up previous contents index
Next: GEOMETRY LINE NODES [lnam] pnam1 pnam2 Up: GEOMETRY LINE Control Previous: GEOMETRY LINE ELEMENTS lnam [elty]

Femsys Limited
1st October 1999