v2m_point x y z
v2m_point "x y z"V2M_POINT(nged)
NAME
v2m_point - transform a point from view space to model space
On this page
SYNOPSIS
DESCRIPTION
The v2m_point command applies the current view-to-model transformation matrix to the given point and returns the result as a space-separated x y z triplet in model space.
The input point is in view space, where (0, 0, 0) is the view center and the axes correspond to the screen orientation. The output is the equivalent position in model coordinates.
The transformation incorporates rotation, scale, and translation — the complete view-to-model mapping, not just rotation. This makes v2m_point the inverse of m2v_point.
The input may be provided as three separate floating-point arguments or as a single quoted space-separated string. Any other number of arguments returns a usage error.
EXAMPLES
Example 1. Convert the view center to model space
mged> v2m_point 0 0 0
Returns the model-space coordinates of the current view center — the point at (0, 0, 0) in view space.
Example 2. Convert a view-space point using a quoted string
mged> v2m_point "0.5 -0.25 0"
Returns the model-space coordinates of the view-space point (0.5, -0.25, 0). The single quoted string form is accepted for scripting convenience.
Example 3. Round-trip check with m2v_point
mged> set vp [m2v_point 100 0 0] mged> v2m_point $vp
Converts the model point (100, 0, 0) to view space, then converts it back. The result should be approximately 100 0 0 (within floating-point precision).
AUTHOR
BRL-CAD Team
BUG REPORTS
Reports of bugs or problems should be submitted via electronic mail to devs@brlcad.org