.. _offsetsurf :

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> **_OFFSETSURF_**

>

>> 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** - &nbsp_place_holder;Compute node angle weighted
normals and keep the vector components in three scalar attributes x_n_norm,
y_n_norm, z_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**&nbsp_place_holder; - Compute the full offset direction vector but set
x component to zero

**yzero**&nbsp_place_holder; - Compute the full offset direction vector but set x component to zero  
**zzero**&nbsp_place_holder; - 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.   

>

>> FORMAT:

&nbsp_place_holder; **offsetsurf**/new_cmo/old_cmo/dist/keyword

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&nbsp_place_holder; EXAMPLES: **offsetsurf/**cmo_out/cmo_in/d

&nbsp_place_holder;&nbsp_place_holder;&nbsp_place_holder;&nbsp_place_holder;&n
bsp_place_holder;&nbsp_place_holder;&nbsp_place_holder;&nbsp_place_holder;&nbs
p_place_holder; offset a triangulated surface a distance d using angle
weighted normals

offsetsurf/cmo_out / cmo_in / d / keep_area &nbsp_place_holder; - offset using
area weithted normals **offsetsurf/**cmo_out/cmo_in/d/[xy,xz,yx,yz,zx,zy]
offset a line cmo a distance d in a direction parallel to the specified plane.
**offsetsurf/**cmo_out/cmo_in/d/x y z offset a line cmo a distance d in the
direction specified by the vector (x,y,z)