Export Rigged Model From Blender To UE4

[anonymous_user_e6a1f270]

You know…I hate to say this… but I’m pretty sure I duplicated and scaled every single vertex in this model at some point. I would not be surprised if this is causing some of my difficulties.

[anonymous_user_f70d3582]

@DyotoOrion;124182

is correct about everything there except the X forward bit. -Y Forward is fine As far as I know.

that’s more of a recommendation then an absolute necessity:)

@OSUNightfall;124316

so I’m not too surprised in retrospect that the methods used weren’t correct when your end goal is for exporting to a particular game engine.

easy enough to do but as DyotOrion says you’ll have a decent workflow in no time:D.

[anonymous_user_e6a1f270]

So I’ve done a little more research on the launcher problem. I figured the problem had to be with one of two things: either the bone the launcher was attached to, or the launcher itself. I removed the launcher bone and added a new bone, attaching the launcher to it. Same result. I then removed the launcher and attached a simple cube to the bone in its place. Once again, the cube appeared behind the mech. It now occurs to me that the animation itself could also cause the problem. I will investigate.

[DyotoOrion]

Hehe, sorry, slightly long 1/2 hour. So all I wanted to say/show this evening is that Animations from Blender to UE4 can work with no problems. Here is an example:

In Blender Blender Spaceship Landing Gear Animation. - YouTube

[DyotoOrion]

And in UE4: Unreal Engine 4 Spaceship Landing Gear Animation. - YouTube

Sorry. Been a bit of a busy (Social) day. Will get the Mech fixed soon. Also good to see Nightfall that you made some progress!

[DyotoOrion]

Okay so, Nightfall, I’ve spend a good few hours trying to debug your Mech Skeletal Mesh and get it working in UE4 with no success I’m afraid.

To be honest I’m not 100% sure what is causing the feet to be dislocated from the body. It could be the set up of your rig, or it could be a legacy issue from your having built it all in parts and then joining the mesh together, and or an issue caused by, I presume, the Anims being made when the Mesh was all in parts right?

Any ways, my best advice at this stage is to start again from scratch with a clean workflow. So today I’ve been experimenting with building a Mech rig using a somewhat simpler method of skeleton building. It’s not finished yet but I figured I would post my test Blend file to show you roughly how I intend to build the rig.

DISCLAIMER: This Blend file contains the most awesome powerful cool MEGA MECH you have ever seen or will ever see!! This Mech model IS COPYRIGHTED and any use of this Mech in your game will constitute copyright infringement and I will sue you for bazillions of dollars!

Here it is: AWESOME SUPER MEGA MECH.blend

Haha! Sorry for the silly joke. Any ways the good news is is that this very basic block model and animation does export correctly from Blender to UE4 and so can hopefully serve as the basis for a good workflow for Blender to UE4. I’ll get the complete Rig done in the next few days hopefully.

[DyotoOrion]

A few important Tips and Notes on Skeletal Mesh building inside Blender:

1. Mesh Objects should never be Translated, Rotated, or Scaled in Object Mode if they are to be used as a Skeletal Mesh in a game engine. Translation, Rotation and Scale of the Mesh object, or any other editing of the mesh object, should be done in Edit Mode. Only change Mesh Objects in Object mode if you know it
   doesn’t make any difference.

2. Skeletal Meshes for UE4 should have a single Bone called Root, that should be spawned at the World Center. 0, 0, 0, (Shift, S, R to move 3D cursor to centre of world then Add Armature or Bone.) and should not be translated, rotated, or scaled. The Root Bone should be the parent of all other bones in the Armature.

3. The Origin of the Mesh and The Armature should both always be located at the World Center 0, 0, 0, unless they need not to be for another reason (Such as a Skeletal Mesh to be placed in a Socket that is not located at 0 0 0.) Select the Armature OR Mesh Object, Move cursor to center of world, then Object Menu -> Transform -> Origin to 3D Cursor.

By not translating, scaling or rotating any objects in Object mode, all of your objects will maintain a scale of 1 and a location of 0 0 0. This is required. If you need to scale your model or armature to UE4 scale, do so in Edit mode.

[DyotoOrion]

Okay then, here is a basic Rig with a Blocky Mech Mesh to show a possible way to set up a Mechanoid Character Skeletal Mesh from Blender to UE4. I have successfully exported this rig and mesh and anim to UE4 with no issues. It has basically the same animation and functionality as Nightfalls original Skeletal Mesh, but without the issues.

This rig has an Inverse Kinematics constraint on both legs and I have added a joint in the main body so that the head doesn’t wobble from side to side.
The feet have “Inherit Rotation” unchecked so that when their parent bones rotate from side to side, they retain their upward facing direction.

The animation itself is not perfect, but similar enough to Nightfall’s original anim, as to illustrate a working rig.

Heres the Blend: MechPrototype_Complete.blend

Hope that’s helpful!

[anonymous_user_e6a1f270]

Thank you for all your help so far, DyotoOrion. I’m going to try and make another mech from scratch taking into account everything learned from this thread. I will let you know how it goes.

[DyotoOrion]

Safe! Hope you get it worked out!

[akka]

@DyotoOrion;125778

Heres the Blend: MechPrototype_Complete.blend

This imports (at least for me) with the same “Imported bone transform is different from original” warning mentioned above.

The mesh imports facing backwards from the way it animates. The mesh still flips around once you play the animation, but there’s still something wrong obviously.

This only happens exporting with FBX 7.4; 6.1 imports the mesh facing backwards from Blender’s forward facing, but I don’t get the transform warning and the animations play the same way the mesh is facing.

[VSZ]

@akka;170754

This imports (at least for me) with the same “Imported bone transform is different from original” warning mentioned above.

The mesh imports facing backwards from the way it animates. The mesh still flips around once you play the animation, but there’s still something wrong obviously.

This only happens exporting with FBX 7.4; 6.1 imports the mesh facing backwards from Blender’s forward facing, but I don’t get the transform warning and the animations play the same way the mesh is facing.

I’m seeing exactly the same behavior - my skeletal mesh faces backwards on import, I get a bone transform warning while the animations themselves work fine as they are flipped in the ‘right’ direction.

Sadly I still haven’t managed to perfect a solid workflow from Blender to UE4. I’ve imported a couple of skeletal meshes over the months and they all work but each has its own set of quirks or hacks to go with it.

If I try importing a stick figure with a very simple rig as an experiment everything just works (with ‘use t0 as reference pose’ of course) but with anything more complex I run into issues like these on import. Ah well - the bone transform error hasn’t affected anything functionally in my game yet so I’ll just assume my rig is complete and move on to texturing my model

Edit: It turns out my stick figure also had the same issue, I must have glossed over it earlier because it was symmetric.

[sushichris]

@DyotoOrion;122949

Hehe nps! Mechs are cool in general.

Okay, let me explain what I mean. The way you are doing it at present is the wrong way to rig Skeletal Meshes in Blender for games. It is not the way Epic Games rig their characters or machines, or the way Skeletal Meshes are rigged for any game engine as far as I know. What you are doing wrong is the act of splitting up of the Mesh into separate Mesh Objects. In the screenshot of your blend I can see you have 20 or more Mesh Objects parented to the Skeleton. Like I said this is not the way to rig for game engines. Why? Because there is a simpler and more efficient way to do it.

The only reason you would want separate Mesh Objects is for vehicle suspension, but that’s a whole other story. What your doing here is essentially using Mesh Objects as Vertex Groups. When really Vertex Groups are what you want to control the different parts of your mesh.

Trust me here , I know what I’m talking about. I’ll explain.

So, here’s how you fix it:

1. In Object mode, select every single separate Mesh Object. (Hold Shift, Right Click on every Mesh Object until they are all high lighted Orange.)
2. Join all the Mesh Objects together into 1 single Mesh Object. (With all Mesh Objects Selected, Press Control + J.) So now if you select the single Mesh Object and enter Edit mode, you will see that all the Meshes are part of the same Mesh Object. The Polygons themselves don’t have to be joined, they just have to all be part of the same object.
3. In Object Mode with the Mesh Object Selected go to Object tab and under the Relations menu remove any Parent.
4. In Object Mode, go to the Modifiers Tab and remove the Armature Modifier.
5. With the Mesh Object select go to the Object Data tab, Vertex Groups menu and remove all the Vertex Groups from the Mesh Object by clicking on the - button on the right.
6. Now in your scene you should have 1 single Mesh Object with no parent and no armature modifier and no vertex groups. This is essentially cleaning the object of unwanted armature data. And you should also have 1 Armature object.
7. Select the Mesh Object and then holding Shift select the Armature object. They must be selected in this order, Mesh first, then Armature Second.
8. Press Control + P and select “With Empty Groups”. Your Mesh is now parented to the Armature and Vertex Groups have been created on the Mesh Object, one Vertex group for every single bone in your Skeleton. But at present none of the polygons in your Mesh are weighted to the Armature.
9. Select the Mesh Object and enter Edit Mode. Navigate to the Vertex Groups panel inside Object Data. Starting at the top with the first Vertex Group, select the Vertices of the Mesh, the Tris or Quads or NGons, that you want to be controlled by the Bone with the exact same name as that Vertex Group. With the chosen Vertices selected press Assign in the Vertex Group panel. Those Polygons will now be assigned to that Vertex group and so weighted to that specific bone. When that Bone now moves, those Polygons will move with it.
10. Repeat this process with every single Vertex Group so that all Vertices/Polygons in the Mesh are assigned to a Vertex Group. All vertices must be assigned to a Vertex Group. Although it is perfectly fine to have a Vertex Group with no Vertices assigned to it.
11. In Pose mode make a Single test animation. Export your Skeletal Mesh as FBX with the animation into UE4 and watch it play!

This is a proper way to Rig Skeletal Mesh characters inside Blender. I hope it works fine for you. If you have any questions or need help with it please ask.

Wow! This really sums it up, thanks for this!

I am going to attempt this with the HEROTPP skelly and makehuman mesh!

[anonymous_user_8da9c75f]

Thx

@DyotoOrion;122987

Safe! Hope it all works fine for ya!

Thanks DyotoOrion, this definitely helped me out as well. I was having similar problems and the posts were definitely helpful.

[Dingo_aus]

Thanks DyotoOrion for the advice and sample file.

Cheers.

[mzprox]

I haven’t use this addon yet, but I intend to and it might be useful for others. The problem which is presented in this video is supposedly fixed in the latest ue4 build.

[Blender]UE4 Tools Addon: Animation tools

[Syntopia]

hmm but how to use ucx_ collision for each of the parts if we have one single mesh ?

[VSZ]

@Syntopia;277769

hmm but how to use ucx_ collision for each of the parts if we have one single mesh ?

Suffix your UCXs as follows: UCX_MyMesh_01, UCX_MyMesh_02 … UCX_MyMesh_n, to support multiple collision shapes mapping to a single mesh.

Excerpt from the docs:

RenderMeshName must be identical to the name of the render mesh the collision mesh is associated with in the 3D application. So if you have a render mesh named Tree_01 in your 3D application, your collision mesh should be in the scene with that mesh and named UCX_Tree_01, and then exported along with the render mesh to the same FBX file. If you need more than one collision object for a mesh, you can extend their names with further identifiers, such as: UCX_Tree_01_00, UCX_Tree_01_01, UCX_Tree_01_02, etc… and they all will be associated as collision for that mesh.

[VidemusOKC]

You’re following Alimayo Arango’s tutorial for making a mech, which is a good tutorial but isn’t designed with game workflow in mind.

Look up vertex grouping. Join all the object meshes into one mesh. Assign all the vertices that are currently separate objects into their own vertex groups, make the vertex group the same name as the bone you want controlling it. Apply Armature modifier to the one mesh.

That’s the basics of it.

I know this because I was in the same spot a few weeks ago. And he didn’t have any clue what I meant or how to get it working with one mesh. I posted what I had found out about vertex grouping to help any newcomers with the same issue I had, but he said it wouldn’t be useful to beginners (and I think he deleted the post lol).

Anyway, the tutorial was good and I learned a lot from it. I credit him for getting me started. He’s just very helicopter about comments on his videos for some reason.

@OSUNightfall;122460

Okay, this is driving me nuts. I’ve created a model of a mech and rigged it with some bones. All of the pieces of the mech are parented to bones and it animates beautifully - in blender. But I’ve had no luck importing this into Blender no matter how many searches I do or how many tutorials on the subject I read. I’ve spent over a day reading dozens of posts but no single post seems to have an answer that works for me. I can import the mech as a static mesh and it’s fine, but if I try to export the skeleton with the mesh, on import everything is split apart into dozens of parts and skeletons, one for each object or bone in the scene.

Here is an image of my blender mesh with the object hierarchy:

All of the objects in the scene are parented to the armature. each piece of the mech is parented to a bone. So that’s the setup. Does anyone have any idea what is going wrong here?

[VidemusOKC]

Also, this. But that being said, you can Apply Rotation, Scale, and Location later on to reset the origin points if you do move objects initially. You just have to be careful because if you do this AFTER you’ve animated it…it will jack up all your keyframes and you have to manually scale them and adjust them which is a pain in the @#$%$.

So, basically, make sure you’re being mindful of your location and scale indicators before you start animating. Like Dyoto said, everything needs to be in the proper spot before you start keyframing.

@DyotoOrion;125360

A few important Tips and Notes on Skeletal Mesh building inside Blender:

1. Mesh Objects should never be Translated, Rotated, or Scaled in Object Mode if they are to be used as a Skeletal Mesh in a game engine. Translation, Rotation and Scale of the Mesh object, or any other editing of the mesh object, should be done in Edit Mode. Only change Mesh Objects in Object mode if you know it
   doesn’t make any difference.

2. Skeletal Meshes for UE4 should have a single Bone called Root, that should be spawned at the World Center. 0, 0, 0, (Shift, S, R to move 3D cursor to centre of world then Add Armature or Bone.) and should not be translated, rotated, or scaled. The Root Bone should be the parent of all other bones in the Armature.

3. The Origin of the Mesh and The Armature should both always be located at the World Center 0, 0, 0, unless they need not to be for another reason (Such as a Skeletal Mesh to be placed in a Socket that is not located at 0 0 0.) Select the Armature OR Mesh Object, Move cursor to center of world, then Object Menu -> Transform -> Origin to 3D Cursor.

By not translating, scaling or rotating any objects in Object mode, all of your objects will maintain a scale of 1 and a location of 0 0 0. This is required. If you need to scale your model or armature to UE4 scale, do so in Edit mode.