picking-ray-testing.py

import FreeCADGui as Gui
import FreeCAD as App
import Part

def pick_ray(start_vec, dir_vec):
    Gui.Selection.clearSelection()
    if App.ActiveDocument.getObject('Line_dir'):
        App.ActiveDocument.removeObject('Line_dir')
    if App.ActiveDocument.getObject('Line_ray'):
        App.ActiveDocument.removeObject('Line_ray')
    if App.ActiveDocument.getObject('Sphere_sect'):
        App.ActiveDocument.removeObject('Sphere_sect')
    view = Gui.ActiveDocument.ActiveView
    info = view.getObjectInfoRay(start_vec, dir_vec)
    App.ActiveDocument.addObject("Part::Line","Line_dir") # line have to be created after picking to avoid intersection
    App.ActiveDocument.Line_dir.Label='Dir'
    App.ActiveDocument.Line_dir.X1=start_vec.x
    App.ActiveDocument.Line_dir.Y1=start_vec.y
    App.ActiveDocument.Line_dir.Z1=start_vec.z
    App.ActiveDocument.Line_dir.X2=start_vec.x + dir_vec.x
    App.ActiveDocument.Line_dir.Y2=start_vec.y + dir_vec.y
    App.ActiveDocument.Line_dir.Z2=start_vec.z + dir_vec.z
    if (info):
        sect_pt = info['PickedPoint']
        App.ActiveDocument.addObject("Part::Line","Line_ray") # line have to be created after picking to avoid self-intersection
        App.ActiveDocument.Line_ray.Label='Ray'
        Gui.ActiveDocument.Line_ray.LineColor = (1.00,0.67,0.00)
        App.ActiveDocument.Line_ray.X1=start_vec.x
        App.ActiveDocument.Line_ray.Y1=start_vec.y
        App.ActiveDocument.Line_ray.Z1=start_vec.z
        App.ActiveDocument.Line_ray.X2=sect_pt.x
        App.ActiveDocument.Line_ray.Y2=sect_pt.y
        App.ActiveDocument.Line_ray.Z2=sect_pt.z
        App.ActiveDocument.addObject("Part::Sphere","Sphere_sect")
        App.ActiveDocument.Sphere_sect.Label = "Intersection point"
        App.ActiveDocument.Sphere_sect.Radius = '0.5 mm'
        App.ActiveDocument.Sphere_sect.Placement = App.Placement(sect_pt,App.Rotation(App.Vector(0.00,0.00,1.00),0.00))
        Gui.ActiveDocument.Sphere_sect.ShapeColor = (1.00,0.33,0.00)
        Gui.Selection.addSelection(info['Document'], info['Object'], info['Component'], sect_pt.x, sect_pt.y, sect_pt.z)
        print(info)
    App.ActiveDocument.recompute()

pick_ray(App.Vector(-3,-10, 1), App.Vector(0.2, 0.5, 0))