So I was wondering what the correct way is to setup blender for UE4. I have tried many different methods and viewed a ton of sites and tutorials and never successfully imported a custom mesh from Blender to UE4 without issue.
Some people say its a scale issue and to set blender to default everything but set scale to 0.01. This has caused scaling issues and the physics asset never works correct, even when placed into the level the scale is correct.
Others say to set scale to 1.0 but set it to centimeters and this has the same result as being correct in level but the physics asset thinks the model is suuuuper tiny.
Others say to set the scale to 0.01 and set it to meters. and this has the same effect and issues as the other methods.
The main issues im having are the physics assets not only scale incorrectly to where when adding and scaling shapes for the physics asset, theyre created several times larger than the entire model for a single bone and when scaled down pop from too small to way too big, as if the model is incredibly tiny. and the smallest they can be is too large. The other issue is when simulate is checked, they 1. Fall through eachother so its as if theyre all being simulated independently and clipping without being a whole. And 2. They are disconnected. So any shape, any model ive used. All one mesh, armature rigged, no armature doesn’t matter, all situations have the same effect, all the shapes pop off as if theyre separate meshes, they clip through eachother and the shapes are unable to scale correctly to the mesh.
Some other issues that have popped up are direction. Everyone says to have your model facing +X axis, all forums, tutorials everything. Yet when they import (and I import) theyre facing to the right in everything. The only time theyre facing forward at the camera and placed correctly is when left at default facing -Y and the settings say -Z forward and +Y Up. (None of this sounds correct to me which only adds to the confusion)
For example, just to practice I tried following this tutorial
And everything was fine and I did exactly what was done here despite my issues with these methods and at 14:33 when he simulates physics I have the same issue I had that he doesn’t. Instead of it working normally, this happens:
There are a couple other workarounds to get the physics asset to have the correct scale. For both of them, the assets in Blender have to be 100 times the actual size to begin with.
Option 1: export the assets (with the large size) and import them with .01 scale.
Option 2: In Blender, create an Empty as a parent of your rig and then scale the Empty by .01. Then export and import as normal.
When you Export from Blender there is a settings popup where you specify +X Forward and +Z Up. There are also settings for animations and bones. Make sure you review all of these before the export.
For vehicles, I followed this tutorial (it’s for 2.7~, but there’s a link to 2.8). I also suspect the bone export from Blender to UE4 may be buggy. I’ve had to reimport some vehicles numerous times. Follow those instructions VERY CAREFULLY.
Edit: I have followed the 2.8 tutorial. It’s basically the same.
I don’t know about the physics asset, but in the case of the axis you are wrong no one says that, all people say to put the forward axis to -Y and the up axis to +Z, which is in fact what it actually worked to you.
Make sure that you didn’t apply the Location transforms of your wheels in Blender. If you do, they will have a location of (0,0,0), and the bones won’t be represented correctly in Unreal. The physics constraints will also not get set up correctly.
Thank you for the suggestions, unfortunately the issues are still a bit confusing but fortunately I think I may have found some work arounds. Since this has been an issue with all my meshes, characters included, this info will be more general. I have been using Blender 2.79 and the latest UE4 builds.
So as far as scaling, ive tested a few different methods and found the one that has the most “normal” results is to just do what everyone says not to. Im not sure why but setting the scaling in blender to meters and metric 1.000 exports perfectly fine. Things are the size theyre supposed to be and no scaling down required. Not sure if this is because the “meters” setting is already scaled down but it seemed to work fine.
As far as the bones detaching, 1. setting external objects (i.e. any mesh not made as one object in blender but many connected to one armature or root object) cannot have location applied, only the root object. 2. when adding an object that has incorrect shapes or amount of bones with shapes, deleting any and adding a new shape completely detaches them and they act as a separate object. Not sure why but many physics assets are not created correctly automatically and this is still a big issue. so the only success ive had has been to leave the default shapes and replace them in the details panel.
As for the orientation, I found that rotating the mesh so the front is +X is actually facing forward, BUT leaving the default settings in the export (-Z forward +Y up, NO force X forward) also makes things oriented correctly.
I still have a lot to test and figure out before i can create a correct ragdoll and custom bones but so far this is what ive found. If anyone has working ragdolls from custom meshes and armatures (NOT using the default mannequin skeleton) id love to hear how you got it working. Thanks!
I have made characters with working ragdolls. The link in my answer describes the settings that I chose. There are multiple ways to achieve the same result, but I chose settings that are most compatible with the FBX exports from UE4. I do that to make things easier in case I use assets from Epic in the future.
Sorry to revive an old thread, but I am having issues that I believe are similar, but none of the solutions seem to work. I have researched this for some hours and made a video demonstrating the issue and outlining things I’ve tried, including recommendations from this thread: Blender Rigify to UE4 Physics Asset is IMPOSSIBLE - YouTube
I apologize for the length but the issue is explained in the first 5 minutes and the rest is me troubleshooting in vain. Hoping I can make a follow up video on how to actually do it because I’m really scratching my head on this one.
