Author: William M. Chan
Date: July, 1999.
SEAMCR is a tool for extracting seam curves, and for decomposing and creating surface grids around surface discontinuities. Under mode 1, seam curves are automatically extracted from a collection of panel networks (PLOT3D surface format) that describe a geometry surface. Seam curves are curves at intersection between components, sharp creases, high curvature contours, and open boundaries. Small gaps between the panel networks are tolerated up to a user-specified absolute distance. After mode 1, the user may need to remove extranneous seam curves, and perform some splitting and/or concatenation to produce a clean set of seam curves. Under mode 2, SEAMCR takes the surface geometry and the clean set of seam curves, and automatically generates spider web surface grids at corners where 3 or more seam curves meet. It also automatically trims the seam curves away from the corners, redistributes points based on turning angle, and outputs a surgrd input file for the trimmed, redistributed seam curves.
(1) Multiple surface panel networks - plot3d format (modes 1,2)
(2) Input parameters (modes 1,2)
(3) Multiple seam curves - plot3d format (mode 2)
(1) Seam curves - plot3d multiple grid format (mode 1)
(2) Spider web surface grids (mode 2)
(3) Trimmed and redistributed seam curves (mode 2)
(4) SURGRD input parameters file (mode 2)
IMODE = 1 Extract seam curves from surface geometry
2 Create spider web surface grid, trim and redistribute seam
curves and create surgrd input files from given surface
geometry and set of seam curves
ISYM = 0 surface geometry not bounded by a symmetry plane
1 surface geometry bounded by x constant symmetry plane
2 surface geometry bounded by y constant symmetry plane
3 surface geometry bounded by z constant symmetry plane
ANG : an edge of a surface panel is picked as a seam edge if
the surface normal of the panel deviates from that of its
neighboring surface panel by ANG degrees ( e.g., a flat
plate would have ANG=0 )
GAPTOL >0 absolute distance tolerated in gaps between surface
panel networks
<0 use default tolerance computed as fraction of diagonal of
bounding box of all surface panels
DSSC >0 global grid spacing for redistributed seam curves
<0 use default
ETAMX,DETA,DFAR >0 marching distance, initial and end spacing for SURGRD
<0 use defaults
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