man gleLathe () - Sweep using a Z-axis shear to create an arbitrary contour along a helical path.

NAME

gleLathe - Sweep using a Z-axis shear to create an arbitrary contour along a helical path.

SYNTAX

void gleLathe (int ncp,
                gleDouble contour[][2],
                gleDouble cont_normal[][2],
                gleDouble up[3],
                gleDouble startRadius,     /* spiral starts in x-y plane */
                gleDouble drdTheta,        /* change in radius per revolution */
                gleDouble startZ,          /* starting z value */
                gleDouble dzdTheta,        /* change in Z per revolution */
                gleDouble startXform[2][3], /* starting contour affine xform */
                gleDouble dXformdTheta[2][3], /* tangent change xform per revoln */
                gleDouble startTheta,      /* start angle in x-y plane */
                gleDouble sweepTheta);     /* degrees to spiral around */

ARGUMENTS

ncp
number of contour points
contour
2D contour
cont_normal
2D contour normals
up
up vector for contour
startRadius
spiral starts in x-y plane
drdTheta
change in radius per revolution
startZ
starting z value
dzdTheta
change in Z per revolution
startXform
starting contour affine transformation
dXformdTheta
tangent change xform per revolution
startTheta
start angle in x-y plane
sweepTheta
degrees to spiral around

DESCRIPTION

Sweep an arbitrary contour along a helical path. The sweep will be performed as a shear along the z-axis, so that the orientation of the contour is displaced, rather than translated, as the contour is swept.

The axis of the helix lies along the modeling coordinate z-axis.

An affine transform can be applied as the contour is swept. For most ordinary usage, the affines should be given as NULL.

SEE ALSO

gleSpiral

AUTHOR

Linas Vepstas (linas@linas.org)