Training Livestream - Blender to UE4 - May 30 - Live from Epic HQ

[cyaoeu]

Hello again Cyaoeu. I think you are confusing two things.

- On one hand, there is the notion of working with a skeleton that is fully compatible with the Epic male. This is what I am talking about - many users are under the impression that it is impossible to create such skeletal meshes in Blender, but as shown with these two assets, it is indeed completely possible (they have all the bones required by the Epic Male skeleton, including the hand, feet and weapon IK bones).

- On the other hand, there is the topic of animating things in Blender. If you want to do that, you do *not* want to add rig controls to the skeleton itself, but rather, build a performer skeleton and rig that does all the things you want, and use bone constraints to apply these movements to the Epic skeleton before export.

I think it is very important to not spread misinformation (even unintentionally) about what is and what is not possible. I would sum it up as follows :

- It is possible to create characters in Blender around the Epic skeleton, and export them out to UE4 for direct use over the default Epic male skeleton.
- It is possible to create animations in Blender using a intermediate skeleton, and either export them out of Blender through bone constraints, or, retargeting them later to the original Epic skeleton once in UE4 (I recently did exactly that for another asset I am releasing on the marketplace soon).

Good luck !

I'm not confusing anything. I said it's impossible to have a normal IK rig in Blender that's compatible with the mannequin rig animations without retargeting. And it is. Sure, you can make a rig that works with the mannequin rig animations but you can't use it to animate with. Or you can have a rig that you can animate with and then retarget animations, which works fine if you set it up right. You can't have both which is the ideal situation. You're just as guilty of spreading misinformation because you're talking about this like there are no issues with the Blender - UE4 workflow when clearly this is something that can be improved.

In your case when you're selling characters on the marketplace it may be useful to use the broken (in Blender at least) rig that allows you to use the animations as they are. But for anyone else who is rigging characters so they can create animations themselves and generally using the skeleton in a game, a rig like that is worthless. Both the UE4 tools rig and the Rigify rig showed on the stream are better options.

[cyaoeu]

Interesting, I am seeing a very different forum skin here. (sorry for the off topic discussion everyone, this is confusing !) :
http://i.imgur.com/qrjWeeo.png

For this there should be a button at the bottom saying Go to Full Site or something, that should make things normal.

[PO_art]

Hello Cyaoeu !

I am not saying that there is no room for improvement. I am simply saying that in the current state of things, using Blender as an authoring tool it is perfectly possible to :

- Create skeletal meshes that are 100% compatible with the Epic Male Skeleton
- Create animations for these characters as well as the standard Epic Male, either by using a proxy skeleton in Blender which can be linked to the Epic one inside the Blender scene (I haven't tried this method, but it should work as all it needs is a link between a performer skeleton and a deformer skeleton through transformation constraints), or by using a performer skeleton of ones choice and converting animations from it to the Epic skeleton inside UE using the animation retarget tool (I just did it for a full set of animations coming from various Maya and Blender sources, relying on a skeleton which itself was structurally different from the Epic male, and later all unified onto the Epic Male Skeleton inside UE4 - it worked very well, better than I expected actually).

The misinformation I am talking about is the widespread idea that "it is impossible to create character models and animations for UE4 using Blender". The process could certainly be better, but it is definitely not impossible. This comment is not aimed at you in particular (you obviously have solid experience in this matter), but at the widespread belief itself.

Finally managed to switch to the full site, thanks ! What an odd system it is.

[cyaoeu]

- Create animations for these characters as well as the standard Epic Male, either by using a proxy skeleton in Blender which can be linked to the Epic one inside the Blender scene (I haven't tried this method, but it should work as all it needs is a link between a performer skeleton and a deformer skeleton through transformation constraints)

This isn't super easy, I tried a long time ago but gave up. What you would need is a copy transforms constraint that doesn't actually copy the transforms right away (keeps original rest pose transforms) but instead copies any delta movement. The child of constraint kind of does this but it doesn't really work with bone chains.

At least now in 4.16 you can export retargeted animations back to Blender using the create animation - preview mesh option, then constrain the control rig to that rig and bake that animation. Then you can edit those animations like any other animation. It should be possible to write some script to automate this, I might do this later if I find some free time.

[ayretek]

thanks for the stream Epic!

good to see some Blender Luv!

[Hevedy]

I expected this to give a clear idea, but make a stream to download the script made by an user that is 1 year outdated, and the root keep duplicated, this makes nothing clear.

[PO_art]

Hi again Cyaoeu !

Yeah I think that sort of stuff is definitely possible. Overall the system is quite remarkably open (with Blender being tweakable at will, and the retargeting tool inside UE4 being very robust). Epic is definitely doing a good job here. I personally believe that the absolute best would be for Epic to create an importer working directly with .blend files + a very clearly established reference scene with a pre-made skeleton in it (with the hypothetical importer taking care of converting bone orientations on import). I feel like this will have to happen sooner or later !

Don't hesitate to let me know if you need any testing whenever you dive back into that sort of stuff, I'd be more than happy to help. As a matter of fact if you already have a Blender animation file using an intuitive performer skeleton I'd be very interested in playing with it to see how far manual retargeting to the Epic Skeleton can be pushed in Blender using delta bone constraints.

[mzprox]

I tried the rigify rig and can confirm that the unreal mannequin and the one from blender looked almost identical while both played a mixamo animation.

At least now in 4.16 you can export retargeted animations back to Blender using the create animation - preview mesh option, then constrain the control rig to that rig and bake that animation. Then you can edit those animations like any other animation. It should be possible to write some script to automate this, I might do this later if I find some free time.

I'm interested in this workflow. Let us know if you find that time to make a script . thanks in advance

[cyaoeu]

Hi again Cyaoeu !

Yeah I think that sort of stuff is definitely possible. Overall the system is quite remarkably open (with Blender being tweakable at will, and the retargeting tool inside UE4 being very robust). Epic is definitely doing a good job here. I personally believe that the absolute best would be for Epic to create an importer working directly with .blend files + a very clearly established reference scene with a pre-made skeleton in it (with the hypothetical importer taking care of converting bone orientations on import). I feel like this will have to happen sooner or later !

Don't hesitate to let me know if you need any testing whenever you dive back into that sort of stuff, I'd be more than happy to help. As a matter of fact if you already have a Blender animation file using an intuitive performer skeleton I'd be very interested in playing with it to see how far manual retargeting to the Epic Skeleton can be pushed in Blender using delta bone constraints.

You can just use the UE4 tools addon rig and create some simple test animation with it. The delta bone constraint I was talking about doesn't actually exist which is the problem. You would need to code a new constraint which doesn't sound like a lot of fun to me. Maybe you could create a new set of non deforming bones in the mannequin rig (at the original location), remove all of the bone parenting for those, then for each new bone add a child of contraint pointing to the control rig bone with the same name. Finally for the original mannequin bones add copy transform constraints pointing to the new non deforming bones in the mannequin rig.

[Yetta]

Missed the livestream

[Abeysaurus]

Anyone else having issues with the "Armature" fix Epic implemented in 4.16? When I import a skel mesh with Armature, I get an error saying "Multiple roots detected". But if I name it something else, It imports properly. But of course with double roots.

[PO_art]

Hi again @Cyaoeu -

Could you please point me precisely to the resource you are talking about ? I do not know what the "UE4 tools addon rig" is. All I know is how to create content that is compliant with the Epic Male skeleton as required by the Marketplace guidelines. Since I personally don't use extra tools for that I am therefore not familiar with what users are currently using or attempting to use. Thanks !

(In other words, I want to make sure to precisely recreate the issues that people are running into).

[cyaoeu]

Anyone else having issues with the "Armature" fix Epic implemented in 4.16? When I import a skel mesh with Armature, I get an error saying "Multiple roots detected". But if I name it something else, It imports properly. But of course with double roots.

If you've got bones on the same level, like root, IK bones or whatever, when the root bone disappears using the "armature" rig name fix, the root bone and IK bones are on the same level and you get the "Multiple roots detected" message. You need to make sure you've got a real root bone and make sure that no bones except the root bone don't lack a parent bone.

It should look like this in edit mode (in the top right outliner):

[cyaoeu]

Hi again @Cyaoeu -

Could you please point me precisely to the resource you are talking about ? I do not know what the "UE4 tools addon rig" is. All I know is how to create content that is compliant with the Epic Male skeleton as required by the Marketplace guidelines. Since I personally don't use extra tools for that I am therefore not familiar with what users are currently using or attempting to use. Thanks !

(In other words, I want to make sure to precisely recreate the issues that people are running into).

It has been mentioned a bunch of times in this thread (and you can just google it) but here it is: http://www.lluisgarcia.es/ue-tools-addon/
Generally you don't have to worry about anything, if the base pose looks the same people should be able to retarget to it. But if you want to create custom animations you're better off using a rig like this and then retargeting them to the mannequin skeleton.

[PO_art]

Thank you for the link ! I'll have to look into it. Bit of a shame that there is no succinct description/synopsis of what this tool actually does or fixes in regard to the default character workflow, and the videos don't seem to have clear introductions. Oh well :/

Overall it seems a bit dangerous to rely on a unsupported third party script for that sort of stuff, but anything helpful is worth looking into for sure.