Ancrage avancé OYX

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Tutoriel
Thème
Attachment
Niveau
Intermédiaire/Avancé
Temps d'exécution estimé
1 heure
Auteurs
drmacro
Version de FreeCAD
0.19 ou supérieure
Fichiers exemples
[TBD]
Voir aussi
None

Les objets en position initiale

Introduction

Cette démonstration traite de l'utilisation du mode d'attachement OYX pour ajuster la position de l'origine d'une esquisse comme décrit dans Part Ancrage, elle n'est pas exhaustive, mais nous espérons qu'elle aidera les utilisateurs à expérimenter.

L'image ci-dessus montre la géométrie utilisée dans cette démonstration.

Le cadre inférieur droit montre la vue supérieure de la scène. Notez que la scène comprend une esquisse contenant un carré et du texte indiquant les axes vertical (Y) et horizontal (X) de l'esquisse. Le coin inférieur gauche du carré est situé à 0,0,0 de l'esquisse (l'origine de l'esquisse).

The origin of the sketch and the global origin (designated by the red, green and blue axis cross) are the same. In the other frames of the image we can see that the square is at Z=0, so the sketch is in the XY plane.

There are two other sketches which include geometry that will be used to re-position the sketch containing the square. One sketch contains an orange line that is oriented along the global Z axis in the XZ plane. The other sketch contains a yellow line in the XY plane.

Discussion

Attachment mode Align O-Y-X is defined as follows in Part:Attachment: Matches object's origin with first referenced vertex and aligns its vertical and horizontal plane axes toward vertex/along line.. It also notes there are several reference combinations.

Reference combinations
Vertex, Vertex, Vertex
Vertex, Vertex, Edge
Vertex, Edge, Vertex
Vertex, Edge, Edge
Vertex, Vertex
Vertex, Edge

Lets start with Vertex, Vertex, Vertex.

If we match the definition to the reference:

The first vertex selected will position the origin of the sketch to the selected vertex.

The second vertex selected will align the vertical axis of the sketch (in the demo setup this axis is indicated with Y).

So, if we select the upper left/upper vertex of the yellow edge (as seen in the larger right frame) and the lower/right vertex of the yellow edge the sketch is positioned like this:

Notes
The Align O-Y-X is selected in the Attachment dialogue.
The sketch origin is now at the upper left/upper vertex of the yellow line.
The Y axis of the sketch is now aligned with the yellow line.
The Z axis of the sketch is perpendicular to the yellow line.

Now if we add a third reference by selecting the upper vertex of the orange edge the scene changes to:

Notes
Now the X axis of the sketch is aligned in the direction of the selected vertex of the orange edge.