UE5 FBX from Blender Import without error has no animation

[Randall_Ericson]

I am trying to make a Free UE5 VR experience and I am at a total loss now. I have looked all over the internet and found no solutions that works for this particular problem. I am using Blender 3.4 and made an animation that I know works as I am able to import the exact same FBX file animation I exported back into a fresh new Blender instance. I have heard that there are some problems with importing animations in UE5, but it is very inconsistent in terms of working for me.

For some reason, when I import my FBX into UE5, it takes a very long time to import (Upwards of about 2-3 hours, assuming it doesn’t crash. Probably as there are 467 bones total in this creature and over 3,000 frames) and there is literally nothing the animation asset is doing. It just sits there in the default pose I used to rig the model. I also tell UE5 now to import about 300 frames specifically as those frames have good movement to test and see if it imported at all. I want to keep this project as obscure as possible until I release it so I will do my best to provide as much information as I can. Feel free to ask for more details if I missed any.

My object model is named something other than “Armature”. The top of the armature bone list in Blender is “Armature.197” with “Root” being the next bone name (I am looking at an older and working version of the animation for this in UE. see image attached). The rest of the bones are named appropriately with anatomy and are all unique with numbers for similar bone structures. I have gotten my model + animation to work several times in the past in UE without changing the bone structure at all or the export/ import settings, but when I update the animation to be more long and complex (Without changing any names, just editing/ adding keyframes here), the animation asset does nothing upon import, even in a fresh instance of UE5. I have also tried baking my animations in blender with no difference upon importing to UE5. I have also uninstalled and reinstalled and verified UE5, all of which were never broken. My graphics drivers up to date as well.

I love UE5, and I really wish to continue in it as it has some of the best features I can use with VR capabilities and is easily accessible, but I have restarted because of UE far too many times with this same exact issue and created several UE5 files just to be sure I am not doing something wrong and nothing is getting confused in engine. I have even looked back at my earlier working UE5 files with the working animation and there are no differences to what I have currently, and often times, when going back, they no long work all of a sudden or crash.

I know there is an import problem in this engine as it has worked several times before and my FBX animation still works out of engine. I saved an FBX export preset in blender that I confirmed several times works. I even looked back at older Blender files I used and I see no differences to what I have now. I also still have some working FBX’s, and its a complete hit or miss when importing it into a fresh new UE5 instance. I’m not even changing the import settings. Thank you for any assistance and I hope this post can help others as well if they have a crazy animation problem like this.

[dblzeero]

Thats a lot of bones and a lot of frames. I had the same issue, but with way less frames and a lot less bones. I use blender, and my solution was simple. In Blender, you have to select the mesh and then shift select the skeleton. After that, you can go to export Fbx.

I use my leaf bones. I use leaf bones (bone ends) for socket points, etc, but I don’t ever have a skeleton that size. The editor brings up errors on import for not having the bone ends weighted, but they should have weights. It’s a hmmm…situation, just carry on. (The ends are the tails of the bones, end of bone hierarchy, thumb 1, thumb 2, thumb 3. The tail of thumb 3 is the bone end. The editor for some reason imports it as thumb 4/ thumb 3 end from blender, something like that).

You might want to also uncheck include leaf bones in the Fbx exporter in Blender.

You can also try, since you see the importer issue, to reset the Fbx importer options. Try changing only the scale and check mark only the force x option on all three importer sections.

Also, since that’s a huge file, try to import only the mesh and skeleton. After that, import the animations separate and choose the skeleton the animations are for. It might be a long shot, but it might work. They all reside in the same file, no extra work, just separating them into two imports.

Hope that helps.

[dblzeero]

With all those bones, if you are using bones for controllers, you also have to have all the bones parented to the root. The skeleton can have one root only. If a controller is not parented to the hierarchy, it will not import. You also only want to animate in pose mode in blender. I’ve tried plenty of other ways to rig like I do in maya, the only way it worked was using bones for controllers. You can change the shape of the bone in the bone options menu to make it look like a controller.

[dblzeero]

The way that hierarchy in blender looks, you have controllers on one skeleton controlling the bones on another skeleton. If that is the case, that’s your issue. I did the same thing in my venture in trying to make a rig like I do in Maya, it has to be one skeleton.

[Randall_Ericson]

Hello. Thank you for your replies. I already select the mesh first and the skeleton second. I also know that Unreal can handle this model and skeleton as the screenshots show (The one with the hierarchy in UE5 was an example of my animation and mesh working and imported successfully) that it is possible. It just takes long. I also have been trying to export the animation into segments that I can then piece together in engine, but that still doesn’t work.

I also tried taking a look (Something I forgot existed) at the UE Output Log and found something interesting. I get these strange errors for every single bone (See screenshot in this reply.) This is a strange problem as this is a 100% fresh new instance of UE5, literally without anything imported (Except for the starter content). There are no other animations or skeletons in this file, and I still get this error for every bone. Maybe this will help in identifying the problem. I already looked online for solutions for this but found nothing that matches this issue. I have heard someone mention a “Binaries” folder, but when I looked at it, nothing seemed off, but maybe that’s
me not understanding the contents.

I will also show you my Blender export settings (These settings worked before, that’s why I made them a preset.)

Thank you again for your assistance.

[dblzeero]

Here’s my FBX to unreal settings. Like I said before, it might suck because I already been through it, but you might have to re-rig the model. That or you can bone it and use control rig and animate everything in the Unreal. The error is coming from the empty object controls. I tried it too, you hook empty objects for bone controls to bones. I never got it to work that way.

You could try going back into blender, this might be a pain if you are animating using timeline. It works to animate on the timeline, it just ends up in pain sometimes.

The second jpg is what you want to do. It works every time, and you don’t have to trim or cut up/edit that long animation strip. Go into the action editor and see if the key frames are still there. If the keys are still there, try to click “Push Down” into a new NLA. I’m thinking that might not work. I think you have to re-rig it, unfortunately. This is why I use all bones for controls, it keeps everything in one skeleton and I can properly parent the controls to the root.

Like I said, you want to animate in Pose mode because object mode is for the entire scene. Individual animations, you want to do them in pose mode. It still works to use timeline, but you want to do in pose mode (I’m bout 90% sure on that because I’m done trying to figure out ways to throw constraints on bones and figure out it might not work right without using a bone. Not a dis on Blender, it’s just Blender has so many options and different ways to do things. I just know this way works for everything). I had issues every different way I could think of to animate in object mode with empties.

The last jpg shows bone shape controls, you can get real slick with bone shapes (You have to turn off their visibility in the viewport/render. The trick is to keep them at (0,0,0). If you need them offset from the actual bone position, you adjust their offset of (0,0,0) in edit mode then re-hide them. I had issues, a couple of times, with weights being off after I had the model in engine). I try not to use bone shapes on the actual bones, just the controls, due to weighting.

Your fix might be my FBX export settings, but I’m almost certain it’s the empties that you are using for controls. If copy the model, unparent it, re-bone it, don’t add controls, and animate it, I bet with my export setting it will import with the animations. I went through, and I am still going through, a lot of fine tuning/figuring out the best way to rig in Blender. All the rigs I see work (Considering time is money; also considering all the time I put in on my own with Blender), all use bones as controls. I learned how to rig in Maya and 3dsMax in school. Sure, if you are making it for someone else to use, make controls. If it’s for yourself…, as long as you know how to. Blender, just use bones for controls and change to controls to bone shapes.

Cool thing about Blender (Maya, when placing bones, you don’t want to rotate and scale the bones when positioning them), you can use the same rig over and over again. You can also alter/adjust/add/or subtract from the rig and use the same rig on multiple different characters. Go to any file you have a character rigged (make sure its saved), unparent the model, delete only the model; now that you have just the rig got to “save as”. Now you have a rig that you can import a new model in and skin it. You might have to adjust some bones/re-calculate the bone rotations, but it will work. If you don’t have to add bones or do anything to the skeleton but skin it to the model, you can reuse the animations too.

I’m telling, all bones, and animate in pose mode.

Hope this helps. I’ve been through the same.

Eeeeww, sorry about that name in the folders. For some reason I can’t get away from it. It was a name of a character I came up with. I used it for my college email (for all my programs and everything I do is linked to it) and it was linked to my pixologic account. Since it was linked to my pixologic account I had to use that email when I first opened this computer. For some reason, the dang thing named my computer it, not me. Even though my account clearly says Steven. I got a lot of stuff for that name, so I truly apologize. I edited it out after I just figured it out. I’ve been taking down ever instance I know of, just can’t get it off my computer.

[dblzeero]

This is a current rig I am using. I could change all the controls to custom bone shapes, but this rig is only for me. I just use the bones(time is money and I’m just making animations to get them into the engine and hurrying up to get right to the logic). I also wanted to see how the model moved and see what I needed to do with the design in Zbrush. I have other bones for bicep/ tricep controls. I can unparent and delete this model. Then I can add the final model, or new model, and use the same animations (If I don’t have to do anything but reposition some bones in edit mode).

Like I said, this is for me to animate. I would obviously change the controls to custom bone shapes for someone else to animate. This is the second model I have used this rig for. I had to delete the arms and add replace them, due to the mechanic muscle controls. Everything else, the keyframes were there and the animations. I had to slightly adjust the positions on the keyframes, but it was minimal work.

if you end up using the action editor, for every action assign a fake user (shield button). If not, you might run in to an issue when you save. Animations might disappear when you close and re-open the file if you haven’t “Push Down”/“Stash” the animations you completed.

Again, Hope this helps.

I looked at your Blender Hierarchy again, I guess you are using all bones. You might just want to open that file, hit “save as”, name it a test file, unparent the skeleton from the model, bone it, skin it, don’t give it controls, do a little anim, and export with my options. If it all works with no constraints/controls, it’s something with the rig. To do more, I would have to see the model and rig.

Sorry I can’t be more help.

[dblzeero]

So you know it works.

[Randall_Ericson]

Hello again. Thank you for your replies! I have already made sure to do everything you said while I was making this. I still don’t understand what I am doing wrong. Since I think I cant get the best help keeping this project obscure, Ill show you the entire Blender file. I was planning on releasing all the related files and assets at the end anyway so anyone can mess with it, hence why the rig is also set up for that. This is also not going to be the final look as this is just testing to see if it works.

Do you see any issue with how I did anything? The methods I showed in my screenshots in my first post was all examples of the UE5 file that still had my animation test, and yes, the animation still works in that one UE5 file. I don’t know what is going on with this but I hope this helps.

When I started this project, I already knew a lot of what I should and should not do, so the only values that I edited was the rotational value of the bones (Except for the IK’s obviously). I never scaled any of the bones either. I also come from a background of animating in Maya so I’m no stranger to weird things happening. I even solved every one of the issues (With help from an instructor some times). I also like to make a basic model of the environment so as to help with the animation, especially if it is to be exported into something else.

Thank you again, and don’t hesitate to ask for more information. I just want this solved for now. Thank you.

[Randall_Ericson]

Also, just in case, this is my project. I’m not hired to do this so there is no worries. Also, this is to be a free VR experience. The name of the movie I am making the experience from is “Nausicaa and the Valley of the Wind”.

[dblzeero]

I need to see just the bones in edit mode. The shot needs to be as close up as you could get with all the bones in ortho side, and another shot in 3/4 side. Only the mesh hidden.

If my fbx settings didn’t work, it has to be something with the skeleton, controls, or the hierarchy. Somethings getting duplicated, obviously. Thats a lot of errors for one leg. I’m thinking it’s a list of errors for all the legs. If the error is only on the fourth leg, show a shot of the fourth leg bones/controllers no mesh.

[dblzeero]

I probably should have said that at first, but I’ve had crazy bone errors before that controllers were really the problem and I had to change them all to fix it. Try also uncheck apply modifiers in the FBX exporter.

I tend to overlook the obvious too. The old engine, UDK, you use to have to use underscore in you naming conventions. Switch the parentheses, spaces, periods, commas, etc… with underscores. Lol, that might be your fix. Underscore every with all you action/animation names and file names. Don’t use anything else but an underscore to separate words on everything you do with the engine. If the file name is “Shaggy dog”, change it to “Shaggy_dog”. If a bone, model, or controller name is “ik.right foot(pole)” change it to “ik_right_foot_pole”.

I have done it for a long time, so it’s auto for me. I totally forgot that could be a thing.

[Randall_Ericson]

Hello. Thank you again for your reply’s. Unfortunately the fixes you that you mentioned that might fix this issue did not work for me. I still got the same errors upon importing my model and animation after I fixed the naming. My previous working animation had the same names with parenthesis and it still worked.

Also, the fourth leg bones are the “rows” of legs. I have four different leg sizes.

Here is more screenshots you wanted. Thank you again for your replies! I really appreciate it!

[dblzeero]

Yep, the rig looks like the issue. I get warned about teaching on the net, so I don’t. I wasn’t even teaching, the college encouraged students to have a you tube channel. I was just showing I know how, and people tripped. What I can say is you want two bones for the leg, that’s it. You want to parent the leg to the spine, that’s right. The Ik should be applied to the last bone of the leg. Then you have the option of “head” or “tail” to position the IK target, depending on how you want the limb to move. The Pole Vector Constraint should not be attached to the skeleton, it’s used to aim the bend point of the Ik chain. The pole vector should be offset and parallel to the bend point of the IK, and it should be parented the Ik target. Then the Ik should be parented to the leg controller. The leg controller should not be part of the skeleton also, but like the “Pole Vector”, you want it in the same skeleton hierarchy. Both the PVC and foot/leg controller both need to be bones (this keeps everything in the same skeleton). You want the IK target parented to the controller. Then you want to parent the controller to the root. That, or you want to parent the controller to another controller that is parented to the root. The controllers should be parented in a Hierarchy inside the same skeleton, but that controller hierarchy should be parented to the root. Parent controllers to controllers, not to the animated skeleton, then some way you should have the last controller parented to the root.

The root bone has changed. Years ago, the root bone was the first bone of the spine. Now, you want the root to be a bone just before spine 1. Blender makes that easy. Create a bone in edit mode; keep it at (0,0,0) and name it the “root”. All controllers should be parented to the root in some way, along with spine1 one. If you have it all right, you should be able to move the root and the skeleton and controllers should all move with the root. All controllers should stay in the places they are needed to be able to articulate the skeleton (where you placed them), and the entire skeleton should move with the root.

The trick “in Blender” with using bones for controls is the purpose of the controls. FK wise, you use the bone to control three things: Location, Rotation, and Scale. if you need to control rotation it doesn’t matter where the bone is. Location, it matters where the bone is, but it doesn’t matter the rotation. For location, it only matters that the fat end orb of the controller bone is in the spot of the bone end orb that you want to control. When it comes to controlling scale, it doesn’t matter the location or rotation of the bone you are using to control scale.

That said, you want to have two bones for your legs, that’s it. You should have only the first bone of the leg parented to spine. The second bone should have the Ik constraint. After that you should have a bone for an IK target, another bone for a PVC, and another for a foot control. Pvc parented to IK, IK parented to foot control, and foot control parented to the root. it seems like a lot, but all of your foot controls should be parented to the root. Skeletons going into Unreal should have only One root. In edit mode, on this skeleton, you should see parenting lines going from the first bone of the leg to the spine. Also, you should see a huge amount of parenting lines going to the root bone at (0,0,0) (Depending on what you are animating; how you are going to articulate the skeleton, and the tools you are using, determines the placement and orientation of the character in conjunction to (0,0,0)/root bone. A shark in water, you might want to have the root/ (0,0,0) at the nose of the shark or mid dorsal if you are animating the shark in a volume. If you’re animating something moving on a surface, you want it somewhere on the lowest point of the character that makes since to animate along a surface) I’m pretty sure you know this, just trying to make sure I am explaining right (Credibility is all. Me, I think of myself as stupid, so I’m nowhere near talking down to you. Much respect).

Thats where you have to start. You have to look at the controls and re-parent them. You might want to switch the naming from having the first character as a number (Maybe “Ik_leg_4” “Pv_leg_4_1”). The engine might not recognize using the parent constraint in the bone constraint menu. You want to make sure that all of your main parenting, controllers/ik’s/pvc’s, is done in edit mode. Parenting in pose mode might not transfer to engine.

Again, this is not an attempt to teach, only help. You just have to do some more editing in edit mode. That, or strip all the controls till you have just the skeleton and use Control Rig. it’s work, but it’s worth it in the end when you see it all come together. To the best of my knowledge, that’s where you need to start in order to finish.

[Randall_Ericson]

Hello. Unfortunately, in order to get the legs to move properly, I need these bones, otherwise the legs of the model will bend incorrectly. If you have ever seen a Nausicaa Ohmu move, you would see this is required in order to get proper movement. I also did everything you said for the most part when creating this skeleton such as the root starting at 0,0,0 and the whole model moving with the root. I also made the leg rig this way so that when I animate it, the legs will stick to the ground when moving, creating the proper “pulling” effect.

There still remains the issue that this rig worked before, and now, all of a sudden, it just doesn’t. Even the FBX’s I had saved and had already confirmed worked in engine, no longer work anymore. Something has to be in UE5 that’s causing this.

I have not edited the skeleton since I created it (And before animating it). Something else must be wrong as I can import this animation again with no problem back into Blender and it works 100% of the time. I’ll try messing with the rig a bit more to see if I cant get it to work again. I might be misinterpreting your response, so please tell me if I am still missing something. Thank you for your replies. I very much appreciate how long you have stuck around for this issue.

[dblzeero]

Here ya, its all g. I love trying to solve problems and helping people. I have to work tonight, when I get off in the am, I’ll rig the body and legs and try to import it into the engine and see if I can get it in. Then ill send you the rig, if it works. This works out for me because if I ever need to rig something similar, ill know what to do. Im pretty fast so ill get back to you by noon central time, or 1pm central.

[dblzeero]

That is crazy, but expected, that it imported earlier. Expected because there is always something that could pop up when there are updates.

[dblzeero]

I attempted to build something similar on a smaller scale.

I was able to import the model and anims into the engine version 5.2.1 with no errors. I have the FBX export setting from blender that I used below. I didn’t UV the model, I gave it a simple walk anim and base pose anim. I just focused on the legs, I didn’t rig the spine. I rushed it, so I forgot to set the bone rotations to +x axis (Don’t worry about changing them, it will make a mess because I should have done it right after I had the bones placed for the controls and skeleton). Like I said, I was just focusing on trying to make the legs the way you rigged them (How I interpreted them from my perspective.

Use the default import setting with couple options different. No “force x forward” (throws an error for transform difference, but it will import if you do) “T0 as reference pose” is checked. The “Import Scale” is set to 10.

I’m going to try to send the blend file to you in a message on here. If not, I will post it here.

Hopefully this gets you there and completed.

[Randall_Ericson]

Hello again. Thank you for your response. I don’t really see much difference where your working animation and mine diverge. I also dont see a Blender file, unless its just the screenshots. I did do a few more tests and came up with some interesting results and theories. I tried exporting my animation as a .glb and it imported A LOT FASTER, but the legs did not move, but the creature was able to turn and bend its body. I also got an interesting Output Log for it as well as import messages. Ill provide a screen capture below.

I eventually thought that maybe its my action or NLA editor. I am using NLA strips that I would bake into one strip and export that, but maybe I am doing it wrong and you might notice something? I also later noticed that objects that were not supposed to be a part of the end animation also got their NLA’s stored in the armature. I tried deleting all but the few strips you will see in the screenshot Ill provide. Thank you again!

[dblzeero]

I sent the file in a message to you. I’ll try to resend it.