I have a simple skeletal mesh - cylinder that can be bent in the middle. I want that cylinder to keep volume when bent. So I created a corrective blend shape for a skeletal mesh in maya then import it all in unreal.
When bent and blend shape applied In maya it looks like this:
Maya and unreal files are attached. To reproduce, pause Corrective_anim around frame 14. I added the curve to the animation in unreal to illustrate the problem. In fact I want to drive the correction dynamically using twist corrective node.
I have taken a look at your files. I brought the fbx into Maya and I see what you are talking about with how adding the blend shape affects the cylinder in appearance. I also imported this same fbx into UE4 4.17.2 and it appears to be the same as the one in maya with the blend shape applied to it. It could be your import settings. I may be misunderstanding what you are trying to do though. I attached some screenshots below to show you what I am seeing. Is the blend shape not importing with your asset correctly?
Hi Ridley,
On your screenshot, it looks there is no blendshape applied. When applied, the joint2 bone should be in the center of the bent place and the cyllinder should be very round where it’s bent. No volume lost.
I made 2 static meshes to better illustrate what i want to achieve, corrected.fbx is how it should look see achievement. Thanks you
If you can give me a complete version of the “correct” one(FBX format), I can test that. As of what I have looked at so far I now understand what you are aiming to accomplish. I think that either your blend shape is not importing with your project or you may have to add more bones/joints to get it to maintain its shape. I had posted the screenshot with the asset not having its blend shape so you could see that it looks very similar to the second screenshot you posted. That screenshot is from Unreal but looks like it does not have the blend shape on it.(my screenshot was from Maya) It came across as the blendspace not importing into Unreal. This is why I was initially thinking it may be an import issue.
I did another version of the fbx, I added the blend shape to the animation. If you import the new fbx you will have Corrective_anim animation, like before, and now it already have the curve. Apply some material that support morph targets then pause the anim at about frame 14. What I see it like that:
I think I found the cause of the problem. I used Post-deformation blend shape in maya. It doesn’t work well with UE. I think it doesn’t event export correctly by maya fbx exporter.
I replaced it wit Pre-deformation shape and it looks the same in maya and ue now.
Certain deformers could also be causing it if you have others applied(this is within Maya) You can find the list of those here. There is also some more detailed information about Post-deformation and Pre-deformation. Unreal Engine does support Blend Shapes and some more general information can be found here. This covers exporting out of Maya and importing into UE. When I imported the fbx into Maya and turned down the blend shape to 0 it looked exactly the same as the one that you had a screenshot of in UE. I hope this is helpful.
