view2model_vec x y zVIEW2MODEL_VEC(nged)
NAME
view2model_vec - transform a direction vector from view space to model space
On this page
SYNOPSIS
DESCRIPTION
The view2model_vec command applies the inverse of the current view rotation to a direction vector and returns the result as a space-separated x y z triplet in model space.
This command transforms a direction vector, not a point. Direction vectors represent orientation or displacement — they have no fixed position in space, so translation does not apply. Only the rotational component of the view transform is inverted and applied. This distinguishes view2model_vec from v2m_point, which transforms a position using the full view-to-model mapping including translation and scale.
Exactly three separate floating-point arguments are required. Unlike v2m_point, a single quoted triplet form is not accepted — the argument count must be exactly 4 (command plus three values).
Use this command when converting a direction expressed in screen/view orientation (such as a movement delta, a surface normal, or an axis direction) back into model-space orientation.
EXAMPLES
Example 1. Convert the view’s forward direction to model space
mged> view2model_vec 0 0 -1
Transforms the view-space vector pointing into the screen (0, 0, -1) into model-space coordinates. The result is the model-space direction corresponding to "into the screen" in the current view.
Example 2. Convert a view-space displacement direction
mged> view2model_vec 1 0 0
Returns the model-space direction corresponding to "right" in the current view. Useful for computing model-space movements aligned with the screen axes.
AUTHOR
BRL-CAD Team
BUG REPORTS
Reports of bugs or problems should be submitted via electronic mail to devs@brlcad.org