If prefabs are blueprints, blueprints need more features

Would love to have some robust prefab support, so if blueprint is the desired method for prefabs then it is missing some key features.

Locking and unlocking instance of the blueprint to randomize placement of meshes of the BP once placed. I would rather not go into the construction script to do this. I want to place the prefab and nudge a table or stool 6 units or whatever. Making multiple instances of these is murder to manage specially if all you are doing is slight transform changes.

The ability to put a matinee component into a BP to properly animate stuff…matinee is already somewhat dated but usable. On the other hand timeline is a dark ages style transform interp tool…no bueno…not trying to be mean with that one, but I’m sure you guys can echo that. This is my biggest request honestly…desperately needing this.

Ability to export the meshes out of the BP…a creation process can form while building a prefab that can make the artist re export some meshes as one piece.

Ability to place sphere reflection capture component actors in a BP

Honestly love the tools overall and appreciate all the updates so far.

Sequencer will come to the editor soon and it will replace Matinee in time. It will also be more functional than Matinee and wont be limited with level blueprint.

There is a tool that you can enable in Editor Preferences > Experimental > Actor Merging. If you enable that you can merge a blueprint(or multiple selected meshes in a level) into a single mesh, which also preserves the lightmap UV’s and turns them into an atlas UV.

wow @ facts

Jacky got the info :cool:

Thx for the info on the actor merging tool that will definitely help with the some of the struggle of prefab’ing with blueprints.

I am eagerly waiting sequencer and hoping to be able to use it, if it is integrated within time for us to implement. Hoping desperately it can be integrated within bps. I could swear I saw it on the roadmap months ago, but I cant find it or the expected release date, so its tough to schedule around.

We’re brainstorming on all of this and are improving the system over time. Conceptually, Class Blueprint = Prefab + Visual Programming, in analogy to C++ Class = Prefab + Code. We need to improve support for persistent instance customization, based on some notion of how instance properties are customized relative to their parent and therefore behave properly as they or their parent are updated. We also need a more systematic approach to creating a Class Blueprint from actors, components and level blueprint nodes.

Thx for taking the time to follow up on this question Tim. Looking forward to seeing what you guys come up with on this front. Is sequencer off the roadmap for now?

By atlas UV, you mean all the meshes in the actor merging will share one lightmap UV? What if the UVs overlapped?

Also will be combined mesh takes up extra memory space (become a new mesh)? The whole idea of using modular design is to reserve memory space.

Can they be unmerged?

One of the issue I have with BP prefab is that it cannot combine sub BP Prefabs. Not in the component editor anyway.
if I have a car, & the car is made up of body & 4 wheels. A wheel is an assembly of tires, wheelhub & 5 nuts.
The standard thing to do in a CAD or 3D package is, make a sub wheel assembly (tires, wheelhub, nuts), then make 4 insatnce of it, & attach it to the carbody

So if I made a BP called wheelAssembly, I will NOT be able to assembly this to my CarBP, not via the component editor which is the natural thing to do. Instead, I have to use the construction script & ke in coordinate etc. Thats just not the natural way to do things. This is coming from an experience engineer (day job) that made mechanical assemblies design.

Won’t the child actor component allow you to do what you want? Add four child actor components to the CarBP, and set them to your wheelBP. Then move them into the positions you want in the component editor.

Not sure what you mean, if there are is a way that can add BP as child actor component, Epic is doing a good job of not letting people realised.

You mean adding extra components to act as parent axes, then attach the wheelBP to the axes? Never tried that before, worth a shot, thanks.

In any case, its still unnecessery exta steps, & you still can’t drop the wheelBPs into the component editor.

Yes you can add another Actor as a child actor. That child actor can be another Blueprint. In the component editor, in the add component menu is a “child actor component” type.


Then in the settings for that component you set the Child actor class. So you would set this to your Wheel blueprint. Then you can move that child actor component into the position you want.


Yes, they will share a single UV for lightmaps and there will be no overlapping as long as your original UV’s arent overlapping. When you merge those meshes it will create a new mesh in the content browser, so mesh wise you’ll have a single mesh but it will have seperate material ID’s for each mesh, so the performance may differ depending on the complexity of your meshes.
And no, they cant be unmerged, but you’ll still have the original meshes in the content browser so that shouldnt be a problem.

Yeah child actor components are the way to go for nesting BP’s inside of BP’s I use this religiously and it’s also great way to make sure there are no dependency overlaps if multiple people are working on the same area. In the example of the car, someone can be working on polishing the wheel components while someone else is working on the body parts without having to stomp on each others work. You can save a lot of time by organizing major components into separate BP’s and the support they have in the editor is pretty solid for this.

Hi :p,
I dont worry if the new prebafs system are calling Megablueprints, daddys or hollyhock meanwhile we have the unreal3 key prefabs characteristic:
-Create from select actors in the editor.
-Change the position, rotation and size of any child in the editor.
-Revert to default.

Ok i did find that “Create from select actors in the editor” and “Revert to default” is already workin :o. Soo only need “Change the position, rotation and size of any child in the editor.” :wink: