sur_exdef - Geometric procedure

Creates a surface
 

Description

Creates a surface from data in a text file. This is a an interface function for the import of surfaces from other systems

The function can handle the following file formats (surfaces):

- VDA-FS polynomial surfaces (for the moment only bicubic surfaces in Win95/NT)
- Bicubic surface from the surface definition system Numerical Master Geometry (NMG)
- Consurf surface from the surface definition system Numerical Master Geometry (NMG)
 

Syntax

sur_exdef(id, file_name, file_type, sur_type, u1, v1, u2, v2:attributes);
 
 

REF	id;
STRING	file_name
STRING	file_type
STRING	sur_type
FLOAT	u1;
FLOAT	v1;
FLOAT	u2;
FLOAT	v2;
INT	surf_no;

Principal parameters
 
 

id	- Local identity
file_name	- File name
file_type	- Type of file (VDA-FS, NMG_F07)
sur_type	- Surface type (POL_SUR, CUB_SUR, CON_SUR, RAT_SUR, LFT_SUR)

Optional parameters
 
 

u1	- Surface U parameter start value for trimming
v1	- Surface V parameter start value for trimming
u2	- Surface U parameter end value for trimming
v2	- Surface V parameter end value for trimming
surf_no	- Requested VDA-FS surface (=0 for all surfaces)

Attributes
 
 

PEN	- Pen or colour number
LEVEL	- Level number
BLANK	- Visible (0) or invisible (1)
SFONT	- Solid boundary and dashed midcurves (0)
SDASHL	- Dashlength

Example

sur_exdef( #2, "/usr/varkon/app/bmw/surflib/doors.VDA" , "VDA-FS" , "POL_SUR", 0 ,0 ,0 ,0 ,4 );

Extracts coefficients for surface number four (4) from the VDA-FS file doors.VDA and creates a new surface #2.

sur_exdef( #3, "/usr/varkon/surflib/gripen/wing.F07" , "NMG_F07" , "CUB_SUR" );

Creates a new surface #3 defined by coefficients in file wing.F07 on directory /usr/varkon/surflib/gripen/.
The of the file is as an output file from the surface definition system NMG.
 

Description of data in a NMG_F07 file with coefficients for a bicubic surface

The order of the patches:

U=0.0, V=NV                                                                                            U=NU, V=NV
 

Patch 19	Patch 20	Patch 21	Patch 22	Patch 23	Patch 24
Patch 13	Patch 14	Patch 15	Patch 16	Patch 17	Patch 18
Patch 7	Patch 8	Patch 9	Patch 10	Patch 11	Patch 12
Patch 1	Patch 2	Patch 3	Patch 4	Patch 5	Patch 6

U= 0.0, V=0.0                                                                                            U=NU, V=0.0
 
 

Surface data header.
 

Surface name	Number of patches		Line 1
SUR/1	594		Example

 

Patch data header:
 

Fixed 0	No of records	Patch no.	Fixed 0	Surface type	Fixed 0	No.of U lines	No.of V lines	Fixed 0	Line 2
0	48	1	0	1001	0	34	19	0	Example

 

Coefficients:
 

a00x

a00y

a00z

1.0

*

1.0

a10x

a10y

a10z

U

*

1.0

a20x

a20y

a20z

U**2

*

1.0

a30x

a30y

a30z

U**3

*

1.0

a01x

a01y

a01z

1.0

*

V

a11x

a11y

a11z

U

*

V

a21x

a21y

a21z

U**2

*

V

a31x

a31y

a31z

U**3

*

V

a02x

a02y

a02z

1.0

*

V**2

a12x

a12y

a12z

U

*

V**2

a22x

a22y

a22z

U**2

*

V**2

a32x

a32y

a32z

U**3

*

V**2

a03x

a03y

a03y

1.0

*

V**3

a13x

a13y

a13z

U

*

V**3

a23x

a23y

a23z

U**2

*

V**3

a33x

a33y

a33z

U**3

*

V**3