This command breaks 3D polylines against a surface. The surface is defined by a 3D grid surface model which can be selected from a .grd, .flt or .tin file or the user can select 3D entities on the screen from which program internally calculates a 3D grid. This routine is one step in 3D polyline design. In this example, a valley fill is designed using 3D polylines as follows:
Source of surface model (File/<Screen>)?
press Enter The File option allows you to choose
the .grd, .flt, or .tin file that models the site. Otherwise a grid
will be calculated
by picking the grid location
and selecting surface entities on screen (ie contour polylines). Using
the File option can be
quicker because the surface is already calculated. Also the .grd file
can be drawn to preview the
existing surface. Use Make 3D Grid File to create a .grd file.
Pick Lower Left limit of surface area:
pick a point
Pick Upper Right limit of surface area:
pick a point
Make GRiD Setting Dialog OK
Select polylines to clip.
Select objects: pick the 3D polylines
Select surface entities.
Select objects: select objects that define the
surface.
Erase polyline below surface (<Yes>/No)? press Enter If
you answer yes, the segments of
the polylines below the surface will be erased from the intersection,
if any, of the polyline with
the surface. Otherwise the polylines will only be broken into separate
polylines at the intersection.
Specify layer names (Yes/<No>)? press Enter If
you answer yes, you will have the
option to
place the broken polylines into different layers.
Before Break 3D Polyline by Surface | After Break 3D Polyline by Surface |
3D view of fill with grid mesh |
Pulldown Menu Location: 3D Data
Keyboard Command: surfbreak
Prerequisite: Plot the 3D Polylines to use for selection and
entities that define a surface.
File Names: \lsp\flatpond.lsp, \lsp\pond.arx