Contrainte Stretch To

The Stretch To constraint causes its owner to rotate and scale its Y axis towards its target. So it has the same tracking behavior as the Track To constraint. However, it assumes that the Y axis will be the tracking and stretching axis, and does not give you the option of using a different one.

It also optionally has some raw volumetric features, so the owner can squash down as the target moves closer, or thin out as the target moves farther away. Note however, that it is not the real volume of the owner which is thus preserved, but rather the virtual one defined by its scale values. Hence, this feature works even with non-volumetric objects, like empties, 2D meshes or surfaces, and curves.

Avec les os, la variation « volumétrique » les met à l’échelle sur leur propre axe local (rappelez-vous que l’axe X local d’un os est aligné sur elle, depuis la racine jusqu’à la pointe).

Options

Target

Identifiant de données (Data ID) utilisé pour sélectionner la cible des contraintes, et n’est pas fonctionnel (état rouge) quand elle n’en a aucune.

Rest Length

This number field sets the rest distance between the owner and its target, i.e. the distance at which there is no deformation (stretching) of the owner.

Reset

Si ce petit bouton est cliqué, il va recalculer la valeur Rest Length, afin qu’elle corresponde à la distance réelle entre le propriétaire et sa cible (à savoir la distance avant l’application de cette contrainte).

Volume Variation

This number field controls the amount of « volume » variation exponentially to the stretching amount. Note that the 0.0 value is not allowed, if you want to disable the volume feature, use the None button (see below).

Volume Min/Max

Limits for the volume preservation to a minimum and maximum scaling each by a Bulge factor.

Smooth

facteur de lissage pour rendre les limites moins visibles.

Volume

These buttons control which of the X and/or Z axes should be affected (scaled up/down) to preserve the virtual volume while stretching along the Y axis. If you enable the none button, the volumetric features are disabled.

Plane

These buttons are equivalent to the Up ones of the Track To constraint: they control which of the X or Z axes should be maintained (as much as possible) aligned with the global Z axis, while tracking the target with the Y axis.