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7.2.99 pick ¶

(pick COORDSYS GEOMID G V E F P VI EI FI)

The pick command is executed internally in response to pick events (right mouse double click).

COORDSYS

= coordinate system in which coordinates of the following arguments are specified. This can be:

world

world coord sys

self

coord sys of the picked geom (GEOMID)

primitive

coord sys of the actual primitive within the picked geom where the pick occurred.

GEOMID

= id of picked geom

G

= picked point (actual intersection of pick ray with object)

V

= picked vertex, if any

E

= picked edge, if any

F

= picked face

P

= path to picked primitive [0 or more]

VI

= index of picked vertex in primitive

EI

= list of indices of endpoints of picked edge, if any

FI

= index of picked face

External modules can find out about pick events by registering interest in calls to pick via the interest command.

In the ND-viewing context the co-ordinates are actually ND-points. They correspond to the 3D points of the pick relative to the sub-space defined by the viewport of the camera where the pick occurred. The co-ordinates are then padded with zeroes and transformed back to the co-ordinate system defined by COORDSYS.