Thanks for the detailed response, gives me some hope to look further into this.
thank you for keeping us updated!
Nice project! 
version 1.3 of the pluggin is out
Can you please show bones on both Mannequin and your character in Blender, so orientation and axes of the bones on both characters is clearly visible?
Also, could you please post screenshot of Blender FBX add-on export settings ?
Thanks
The bones of the UE4 mannequin in the Blender screenshot are not really imporant. You could examine them if you just use the UE4 plugin for Blender from Lui (link posted above). However even a UE4 mannequin without any bones (just a static mesh) would do. They was not used in any way. The mannequin is just in Blender to get a clue how the pose of the girl should look like. Even the axes of the anime girl are not important. There was not any special twists done or something like that. Just pose it like you would do with any non-UE4 character as well. The pose is important. It should look similar to the UE4 one. The closer the better. If you are done with posing make your pose to the rest pose. Rest pose means: Apply the armature modifier if your new pose looks ok. Afterwards “Apply Pose as Rest Pose” in pose mode of Blender. Your mesh should not visually change if you do that so it’s important to apply the armature modifier previously. If the Rest-pose of the armature was successfully changed then you could safely add a armature back as modifier from your mesh and choose your armature again (all those vertex groups are still there so it would follow your armature again).
I usually use this settings (Blender 2.78 uses tabs but it’s still the same settings):
If I export animations I export twice: First time the skeleton mesh in its rest pose without any animation. And in a second export the animations without the mesh (almost the same settings but usually I don’t export “All actions” and even disable “NLA strips” for anims). Afterwards import the skeleton mesh in UE4 first and if you import the anims choose the imported skeleton.
I’ve exported hundrets of time this way from Blender into UE4 without any issues or errors and I’m using my own anims and various market-place anims. If you would use the mesh finally then I would recommend to rename the bones already in Blender (so it’s easier to retarget afterwards in UE4 as you don’t have to move through every bone manually). And I would strongly recommend to add twist bones so anims like “hold rifle” (or other anims where you turn your hand upwards) looks correct. If you would create your own anims in Blender it would make your life a lot easier if you additionally add some IK bones. You don’t really need it for UE4 (you could even use IK functions of UE4 without extra IK bones). But you could animate a lot easier in Blender (https://www.youtube.com/watch?v=cGvalWG8HBU).
Hi, I really want to do this but I can seem to get it right. Would it be possible for you to make a quick video on this please? Would be much appreciated.
Can someone make a vidoetutorial of this?, I was able to delete the root bone, but I have 0 knowloadge in blender, so I dont really know how to do te rest, by the way versión 1.4.0 is out
+1 to the Mike090y9’s request.
Also curious, how does MakeHuman / Manuel Bastioni Lab plugin deal with UE 4 twist bones and support for Two Bone IK?
See this post by Sioda to understand the issue:
I’ve been tooting his horn for a while but I didn’t really understand who Manuel was. No wonder it’s so awesome and he promoted it. I thought it was a good friend who he allowed the use of his site design and promoted. Anyhow, I might turn around and try getting the newest models to work with UE4 again when I get the time. Perhaps he should add a really quick UE4 pose to his pose presets to make it easier.
Just tried with 1.4 … it’s still possible. However it now includes shape keys (morph targets) and the skin is cycles (and not blender) anymore. Shape-keys (morph targets) are great because you could do some emotions via some 0-1 silder for mouth for example. But it makes replacing the rest pose a bit more difficult. Skin is a bit more difficult either as the cycles renderer is only great if you would render some pose direct in Blender but does not really export that well as fbx.
Anyway - quick example made with 1.4 - Skin replaced with some solid colors. Hairs are not included with the plugin but created by myself for another mesh a few months ago. Anim-set is based on Kubolds (market place) and left hand for rifle follows via IK. I think I could create some tutorial (including twist bones, IK, some weightpainting for other mesh and including Makehuman as it does not differ that much regaring that) but I would figure out how to include/export shape-keys first (as they would be a nice gift if they would work in UE4). If you wanna get some quick result … just delete all shape-keys (the rest should still work as I wrote above).
Thanks but I wouldn’t want to delete the shape keys, as I have no way to replace them. Manuel needs to take into account the UE4 crowd and allow for a replacement rest pose that is similar to the mannequin. Maybe call it UE4 Rest. I could see how one could use the rest pose and shape keys, simply apply both as a model then reapply it into a new model. As it stands, I am thinking about completely doing all the animations on my future webcomic (plus goof off games) in order to preserve the weight paints of the models.
I did notice that he removed the actual expressions. Instead, he gave us a blank slate to mix and match, making our own expressions. It would make it easier, and allow for complete customization of the characters. After all, no two smiles are exactly alike, even among family members. 
Just had a bit spare time. Morph targets require some more steps in Blender but just works fine afterwards:
*) Pose your mesh to look as similar as possible to UE4 one. It does not have to be perfect. Probably think of Ripley jumps into the yellow robot before they showed evil alien who’s boss.
*) I would recommend to test with a copy of your mesh without shapekeys first (to check if your pose works well). After you think it’s good and retargeting works well come back for shapekeys. I would recommend this because there are a lot of steps to do… and if you have to do this again because you would modify your rest pose a bit afterwards it might hurt. 
*) Don’t modify any shape-target yet (or if you did just switch back to base). They are below that symbol that looks like a triangle.
*) Copy the original mesh. I would call it mesh-copy-1 for now.
*) Remove all shapekeys from the mesh-copy-1.
*) Remove the submesh modifier (as it would create > 400k triangles which would be a bit too much) from mesh-copy-1 (modifiers are at the menu next to that triangle that looks like a wrench).
*) Apply the 2 remaining modifiers (including armature) modifier from mesh-copy-1 (which is now possible be cause this copy does not contain any shapekeys yet anymore).
*) Copy the original mesh again that still includes the shapekeys. I call it mesh-copy-2. So we have now 3 meshes. Our original (with shape-keys), our mesh-copy-1 (without shape-keys) and mesh-copy-2 (with shape-keys).
*) Now select the mesh-copy-2 that contains shapekeys.
*) Choose one shapekey of the mesh-copy-2 and move the value slider to max. For example make the mouth smile. Only choose one shapekey.
*) Remove all shapekeys of mesh-copy-2. Do this manually and remove the shapekey that you just modified as last one (so in this example the mouth).
*) Remove again the submod modifier to keep triangles low and apply the other both modifiers at mesh-copy-2 now. The emotion should not change at this step (it should still smile).
*) Still selected mesh-copy-2 press Alt-C. Choose “Mesh from Curve/Meta/Surf/Text”.
*) Now select mesh-copy-2 first and mesh-copy-1 as second (hold shift and just select the meshes in the outliner).
*) Go to the shape-keys of mesh-copy-1 (which should be empty coz we deleted all) and choose “Join as Shapes” (pressing the small down arrow at right in the shapekeys menu).
*) This would add the mouth-shapekey to mesh-copy-1 (named like the mesh was named - so just rename it to something like “mouth_max”).
*) Delete the mesh-copy-2, we don’t need it any longer.
*) Repeat this steps for all other shape-keys. Create a further copy of the original (that still keeps all shapekeys), pick a further emotion one and so on. Yep I know… lots of steps to repeat.
*) If you finished all this steps then select your armature. Switch into “Pose mode” - hit Ctrl-A and “Apply Pose as Rest Pose” (mesh should not change at this step).
*) Add the armature back again as modifier to your mesh (selecting your mesh and click on that wrench symbol).
*) Select all objects (mesh, armature, …) and do some Apply “Rotation and Scale” (just to be sure)
*) You could now delete your original mesh. So only “mesh-copy-1” remains, including all shapekeys and the correct rest pose.
*) Export as fbx. Done.
At import just make sure you have “morph targets” selected. Shapekeys (Blender) = Morph Targets (UE4). It should give you 0 errors.
Result (just copied 3 for testing):
Thanks! I’ve been trying to figure that out, I have clipped it and put it in an Evernote notebook for quick reference.
It’s even easy possible to add your own morph-targets via the same method. So you could create lots, lots of different emotions without adding any further bones. Just create a copy of the original-mesh again… remove all shapetargets (so you could modify the mesh)… enter the edit mode and move around vertices. If you are done go back to object mode, do that ALT-C thing again and join as further shapekey. But there are already a lot of existing ones. And for a normal game I would not add too much, as this could even affect performance. But just a few already differs a lot and makes your character look much more alive.
hello again Neutronux, sorry if I sound a bit dumb but i had been trying to follow your comments to import the blender mesh into UE4, not sure why but when I import it into ue4 i got this message:
and I also had been haveing trouble with the animation retargeting of the walk animation from the manequin, I made the carácter with manuel lab then exported as DAE then reimported it into blender to delete the root bone, and then exported it as an fbx, not sure what im doing wrong so far.
Maybe is because Im using the caucasican female base instead of the anime one?
the bones with trouble are mostly the bones of the hands and the breasts as far as i can see,
here is a picture that shows the hand bones structure in blender:
and this is the list of the bones that the current mesh has
a was trying to follow the retargeting tutorial on Skeleton Assets: Anim Retargeting Different Skeletons | 03 | v4.8 Tutorial Series | Unreal Engine - YouTube
and then I went to the part of the retargeting itself but the mesh dosent show up in the retargeting Windows
and i think I did the retargeting part well, here is another picture
and when I see the animation created (supposedly manequin idle) a weird animation of hands appear:
I had been traying all day to make the retargeting animation with the manequin and a mesh created in manuellab, my best result was doing:
1)make a mesh in blender using manuellab
2)export as .dae
3)in a new blender file import the .dae and delete the root bone in edit mode
4)export mesh and armature in .fbx using Y axis as forward and Z axis as up
5) import the fbx into máximo wesite to check out if the hand bones didnt change their position
6) if they were mixed up, use the edit map tool in the webpage to arrange the bones as they should be
7) download the new .fbx file with the right arrange of bones
8) import into UE4 with a rotation of -90 degrees in the X axis
9) retarget bones in manequin as humanoid type
10) retarget bones in your mesh as humanoid type
11) cross fingers
and this is what I got…
There should be no error and even no warning.
Regarding the “no smooting group” warning:
Make sure you assigned some smoothing to your mesh. Select your mesh in Blender, enter edit mode (Tab), select all (A+A) and at left toolbar (T) go to “Shading/UVs” and choose a shading (usually smooth if you would do some human and flat if you would do some hard faces like a robot or machine) and/or you could press “W” and choose the shading their either.
Afterwards when you export it to FBX go in the “Geometrie” tab and at “Smoothing” choose Face. Regarding that “end” bones (that should not be there anyway) go to Armatures and remove “Add Leaf Bones”.
Regarding the bones… I would recommend to rename the bones already in Blender (spine01 -> spine_01 and so on). It would be easier to avoid mistakes at clicking through all those pulldowns at retargeting in UE4 afterwards. Retargeting of finger works. However don’t use the 00 bones. Means ignore “index00_l” and start mapping with index01_L -> index_01_L. You’ve got more bones than the mannequin one (which is perfectly ok). Just make sure that those bones below pelvis follow the “skeleton”:
If you changed weight-painting even make sure you normalize all weights so every vertex got enough weight (there’s an option in Blender to do so). If for example a vertex just got 0.3 at spine_01 and 0.4 at spine_02 (and none else) it’s just got a sum of 0.7. It’s too less weight (and should be fixed to get 1.0 anyway). UE4 differs from Blender in such a fallback case and weight the missing 0.3 to the root bone while Blender seems to weight it to the nearset bone (which usually looks ok at human meshes). If some weight of your fingers is put to the root bone it would look terrible in UE4 afterwards.