Offsets triangulated surfaces in the direction of the surface
outward normal, i.e., normal surface motion. For each node a 'synthetic' unit
outward normal N is computed based on the weighted average angle of
the normals of the triangles shared by that node. old_cmo
is the surface to be used in generating the
offset surface. new_cmo is the name of the new surface.
To add the nodes in the new surface to the
main mesh object use the copypts command. To add the new surface to
the main mesh object use a surface command with new_cmo as the sheet name (e.g.
surface/s2d/bndy_typedist is given in user coordinates (i.e. whatever units the old_cmo mesh object was defined
in.) The new node coordinates, R_new, are computed using the formula:
R_new = R_old + dist * N_node
Various keywords control the behavior of the command:
The following keywords can appear in the 5th, 6th, 7th or
8th argument position.
keepatt, keep_angle - Compute node angle weighted normals
and keep the vector components in three scalar attributes x_n_norm, y_n_norm,
keep_area - Compute node area weighted normals and keep the vector
components in three scalar attributes, x_n_norm, y_n_norm, z_n_norm
xzero - Compute the full offset direction vector but set x component
yzero - Compute the full offset direction vector but set
x component to zero
zzero - Compute the full offset direction vector but set
x component to zero
The following keywords can appear in the 5th argument position.
xy, xz, yx yz zx zy - these keywords constrain the offset to
be parallel to the specified plane. These arguments can be used with a line
type mesh object to constrain the offset to a particular plane.
offset a triangulated
surface a distance d using angle weighted normals
offsetsurf/cmo_out / cmo_in / d / keep_area - offset using area weithted
offset a line cmo a distance d in a direction parallel
to the specified plane.
offset a line cmo a distance d in the direction specified
by the vector (x,y,z)