#### GEOMETRY_SEED_COORDINATE

###### Geometries
*GEOMETRY_SEED_COORDINATE
"Optional title"
gid
$x$, $y$, $z$, $\alpha_c$, pid
##### Parameter definition
VariableDescription
gid Geometry identification number
$x$ x-coordinate
$y$ y-coordinate
$z$ z-coordinate
$\alpha_c$ Cut-off angle
default: $45^\circ$
pid Optional part ID
default: not used
##### Description

This command is used to define a surface from a seed coordinate. The surface propagates from the external element face nearest the given seed coordinate. $\alpha_c$ is the angle between two faces that defines the boundary of the surface (default $\alpha_c = 45^\circ$).

##### Example
###### Pipe with varying diameter

Example of a pipe with reduction in diameter. One might want to apply a lower pressure at the section with reduced diameter.

GEOMETRY_SEED_COORDINATE is used to select the inner surfaces of the different sections of the pipe. The Cut-off angle, $\alpha_c$ is used to define the boundaries of the sections and is set to 10, 15 and 10 for the seed coordinates respectively.

*UNIT_SYSTEM
SI
*PARAMETER
R1 = 0.05, "narrow section radius"
R2 = 0.10, "wider section radius"
t = 0.003, "wall thickness"
h1 = 0.10, "height section 1"
h2 = 0.15, "height section 2"
h3 = 0.25, "height section 3"
N = 4, "mesh density parameter"
ang = 90, "Pipe angle in circumferential direction"
tend = 0.001, "Termination time"
*TIME
[%tend], , 1.0e-6
*OUTPUT
[%tend/5]
#
# --- MESH ---
#
*COMPONENT_PIPE
1, 1, 70, [4*%N], 1, , [%ang]
0, 0, [%t], 0, 0, [%h3], [%R1], [%R1+%t]
*TRANSFORM_MESH_CYLINDRICAL
1, P, 1, 1, 111, 111
*COORDINATE_SYSTEM_CYLINDRICAL
1, 0, 0, 0
0, 0, 1, 1, 0, 0
*FUNCTION
111
0.5 * H(z-%h1) * (cos(180*min(1,(z-%h1)/(%h2-%h1))) - 1) * (%R1 - %R2)
*CHANGE_P-ORDER
ALL, 0, 3
*SMOOTH_MESH
ALL, 0, 45.0
*MAT_METAL
1, 7800.0, 210.0e9, 0.3
1
*FUNCTION
1
5.0e8 + 5.0e8*epsp^0.3
*PART
1, 1
#
# --- GEOMETRY SEED COORDINATES ---
#
*GEOMETRY_SEED_COORDINATE
1
0, 0, 0.05, 10
*GEOMETRY_SEED_COORDINATE
2
0.025, 0.025, 0.125, 15
*GEOMETRY_SEED_COORDINATE
3
0.05, 0.05, 0.20, 10
#
# --- APPLIED PRESSURE ---
#