I parented a light source to an object, Is there a way to apply a modifier to both?[cycles]

Question

I'm trying to make a street lamp, so i parented a light source (an area light) to the lamp object. The problem is when I add an array modifier to the lamp it only applies on the lamp mesh leaving me with only one light source. Is there a way to make it applicable to both the object and the light.

Thanks!!

Answer 1

No, that's not possible. But I think you can achieve what you are trying to do in a different way.

1. Make a new collection

2. Name the new collection "light post" (or something else) and move the light and mesh to the light post.

3. Remove the "array" modifier from the mesh.

4. Hide the collection you just made and select the main collection again

5. Select Add -> Add collection instance

6. You can see the light and mesh appear in the scene.

7. Copy the collection instance as many times as desired.

8. Notice that if you edit the mesh or light all instances will follow, thus giving you effectively the same non-destructive workflow as the array modifier does. You can also add other meshes, lights, cameras etc. to the collection and all instances will reflect it.

Answer 2

I have also been trying to add lamp posts along a road path via blender scripting, and here's the solution I applied:

1. Add a lamp post mesh which will become the parent of your light source (If your mesh consists of multiple parts, join them by 'Boolean Modifier > Union')
2. Add array modifier (and curve modifier if your road path is a curve) to your lamp post object to copy it along the road, then apply the modifiers
3. Apply 'Seperate > By Loose Parts' to your lamp post object to get multiple objects instead of one
4. For every lamp post, add a light source and make the lamp post the parent of light source

You can see my approach in code down below:

bpy.ops.import_mesh.stl(filepath=os.path.join(os.path.dirname(bpy.data.filepath), "models/lamp.stl"))
lamp_ob = bpy.context.selected_objects[0]
bpy.data.collections["Lights"].objects.link(lamp_ob)
bpy.context.scene.collection.objects.unlink(lamp_ob)

if laneCount == 3:
    lamp_ob.location = (0,4.2,0)
else:
    lamp_ob.location = (0,3.2,0)

lamp_array_mod = lamp_ob.modifiers.new("LampArray", 'ARRAY')
lamp_array_mod.fit_type = "FIT_CURVE"
lamp_array_mod.curve = road_curve
lamp_array_mod.constant_offset_displace = (15,0,0)
lamp_array_mod.use_constant_offset = True

lamp_curve_mod = lamp_ob.modifiers.new("LampCurve", 'CURVE')
lamp_curve_mod.object = road_curve

for modifier in lamp_ob.modifiers:
    bpy.ops.object.modifier_apply(modifier=modifier.name)

bpy.ops.mesh.separate(type='LOOSE')
bpy.ops.object.origin_set(type='ORIGIN_CENTER_OF_VOLUME')

for index, obj in enumerate(light_collection.all_objects):
    bpy.ops.object.light_add(type='POINT', radius=2.0, location=(0,-0.25,1.25))
    light_ob = bpy.context.selected_objects[0]
    light_ob.name = "Light" + str(index)
    light_ob.parent = obj
    light_ob.data.energy = 500
    light_ob.data.specular_factor = 10  

This may not be the best scripting practice and there are some lines not related to the solution, so anyone can reach me out if any further explanation is needed :)

Footnote: I use .stl models since texture is not required for models in my case.