GE VOLUSON 730Pro Basic User Manual page 249

Definition of the Surface Geometry
The Surface Geometry is defined by rotation of an image plane about a fixed axis (main contour axis)
and the definition of 2D contours in each plane. The 2D contours can be defined manually or by a
sphere. The rotation step for each contour plane is selectable in the range from 6 to 30 degrees (30 - 6
contour planes).
The Surface Geometry is defined by 3D triangularization of the 2D contours, meaning each point of
the 2D contour in plane N is connected via a triangle mesh to corresponding points in plane N-1 and
plane N+1.
Definition of a Shell Contour (Geometry)
The basic idea of a Shell Contour is, to define a "thickness"' of the "reference"' surface geometry.
Display of a Shell Geometry (contour rendering)
The shell geometry can be visualized as "Skin" or "Wire Mesh".
review: Render Mode and Display of the Shell Geometry
The image shows the different visualization techniques. VOCAL shows a surface Mesh.
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Voluson 730Pro - Basic User Manual
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The "'parallel" contours shown in the image define the
"parallel" surface geometry (describing the shell).
The "parallel" contours are either defined symmetrically to
the reference contour or limited to one direction, inside or
outside.
The Shell Geometry consists of one outside and one inside
surface and therefore it is possible to distinguish between
points enclosed by the shell geometry and points outside of
it. A Shell Contour represents all points enclosed by the
inner and outer surface geometry.
If no Shell Contour is defined explicitly, the Shell Geometry
consists of the reference surface (outside surface) and an
inner point (the inside surface being degenerated).
(chapter 11.6.4)
Volume Mode
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