Select other object while in Edit Mode

Question

Is there a way to select another object while in Edit Mode of a first object? I would like the first object to go out out of Edit mode and become unselected/inactive when another object is selected. That newly selected object could be in either Object or Edit mode, currently undecided. Is there a way to either code this ability or change the hotkeys somehow?

I know the preset way that Blender behaves is to not allow selecting another object when in Edit Mode of a first, unless they are joined etc. I'm looking for a slightly different workflow.

Answer 1

Change object in edit mode

import bpy
from bpy_extras import view3d_utils
def select_obj(context, event, deselect_first=True):
    if deselect_first:
        obj = context.object
    bpy.ops.object.mode_set(mode='OBJECT')
    ray_cast(context, event)
    if deselect_first:
        obj.select_set(False)
    bpy.ops.object.mode_set(mode='EDIT')
def ray_cast(context, event):
    """Run this function on left mouse, execute the ray cast"""
    # get the context arguments
    scene = context.scene
    region = context.region
    rv3d = context.region_data
    coord = event.mouse_region_x, event.mouse_region_y
# get the ray from the viewport and mouse
view_vector = view3d_utils.region_2d_to_vector_3d(region, rv3d, coord)
ray_origin = view3d_utils.region_2d_to_origin_3d(region, rv3d, coord)

ray_target = ray_origin + view_vector

def visible_objects_and_duplis():
    """Loop over (object, matrix) pairs (mesh only)"""

    depsgraph = context.evaluated_depsgraph_get()
    for dup in depsgraph.object_instances:
        if dup.is_instance:  # Real dupli instance
            obj = dup.instance_object
            yield (obj, dup.matrix_world.copy())
        else:  # Usual object
            obj = dup.object
            yield (obj, obj.matrix_world.copy())

def obj_ray_cast(obj, matrix):
    """Wrapper for ray casting that moves the ray into object space"""

    # get the ray relative to the object
    matrix_inv = matrix.inverted()
    ray_origin_obj = matrix_inv @ ray_origin
    ray_target_obj = matrix_inv @ ray_target
    ray_direction_obj = ray_target_obj - ray_origin_obj

    # cast the ray
    success, location, normal, face_index = obj.ray_cast(ray_origin_obj, ray_direction_obj)

    if success:
        return location, normal, face_index
    else:
        return None, None, None

# cast rays and find the closest object
best_length_squared = -1.0
best_obj = None

for obj, matrix in visible_objects_and_duplis():
    if obj.type == 'MESH':
        hit, normal, face_index = obj_ray_cast(obj, matrix)
        if hit is not None:
            hit_world = matrix @ hit
            scene.cursor.location = hit_world
            length_squared = (hit_world - ray_origin).length_squared
            if best_obj is None or length_squared < best_length_squared:
                best_length_squared = length_squared
                best_obj = obj

# now we have the object under the mouse cursor,
# we could do lots of stuff but for the example just select.
if best_obj is not None:
    # for selection etc. we need the original object,
    # evaluated objects are not in viewlayer
    best_original = best_obj.original
    best_original.select_set(True)
    context.view_layer.objects.active = best_original



class ViewOperatorRayCast(bpy.types.Operator):
    """Modal object selection with a ray cast"""
    bl_idname = "view3d.modal_operator_raycast"
    bl_label = "RayCast View Operator"
def invoke(self, context, event):
    if context.space_data.type == 'VIEW_3D':
        if bpy.context.mode == 'EDIT_MESH':
            select_obj(context, event)
            return {'FINISHED'}
        else:
            self.report({'WARNING'}, "Edit Mode only")
            return {'CANCELLED'}
    else:
        self.report({'WARNING'}, "Active space must be a View3d")
        return {'CANCELLED'}



def register():
    bpy.utils.register_class(ViewOperatorRayCast)
def unregister():
    bpy.utils.unregister_class(ViewOperatorRayCast)
if name == "main":
    register()

How to Use

1. run script
2. go to edit mode
3. mouse focus on other object
4. run operator by search menu: RayCast View Operator

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