• Godot Help3D

  • Seamless mesh looping animation stops at the last frame before looping

I have a seamless machine looping animation made in Blender, that loops perfectly both in Blender and UE.

It's a machine rotation animation, the 1st frame is the bone rotation at 0 and the last frame at 354 degrees.

When I export either as FBX or GLTF and play it in Godot, it stops for a frame in the last animation frame before looping, thus in Godot I can't make it loop seamless.

It may be hard to see with this compressed video, so here's a reproduction project (Godot 4 alpha16) and even a sample blend file:
https://www.dropbox.com/s/vg49j0emycuv2fq/LoopingMachineFreezing.zip?dl=0

This happens on both Godot 4 and Godot 3.5. So I wonder if for Godot I should do something different for it to loop? (Since it works in UE perfectly).

  • I fixed this bug in Godot today, details: https://github.com/godotengine/godot/issues/65513#issuecomment-1287828202

    I mean, it's not a fix to the import but itself, but it removes the duplicated frames which cause the seamless animation to not be seamless anymore when imported into Godot.

    It's unlikely it's going to be merged into Godot, so you have to get the code from my branch and build Godot yourself.

You're right. It seems to be broken. I tried a lot of things (in Godot and Blender) and I could not get it to loop seamlessly. Probably a bug, you should write a report.

    Okay, I commented there. Hope it helps.

    This may be a dumb question because I haven't done any animations in Godot yet, but are you sure the timeline doesn't go maybe one frame too far, thus introducing the stutter ?

      Pixophir That's the most important question 🙂

      And it's the 1st thing I thought, then to make sure, I tried all engines, the animation plays perfectly in all engines and in Blender - so that's why I think it's an issue with Godot.

      EDIT: I even recently tested in Flax Engine as well and it loops perfectly there too.

        So, yeah, I checked that. In Blender the animation was 60 frames. Exporting at 60 FPS should give 1 second of animation. However, the render setting in the options was set to 24 FPS, causing a strange export (it was like 2 and a half odd seconds in Godot). This was the first thing I checked. In the Godot import settings, it was set to 60 FPS, which should have brought it in correctly, but I guess there is a double conversion happening. However, even after I fixed it in Blender (to be 60 FPS) it was still 1.017 seconds in Godot (one extra half frame). I manually changed it to 1.0 second, but that did not fix it. I even tried putting wild values for the timeline, like 0.8 seconds or 1.5 seconds. In either case, there was a slight pause (looked like 1 or 2 frames) and then an interpolation, to the first frame. The one thing I did not try was deleting the last frame in Blender, and allowing Godot to do it's interpolation. I imagine this might result in acceptable behavior, but the fact that the animation works in Blender, Unity, and Unreal, leads me to think there is a bug.

          cybereality
          Thanks for further testing it! I did the same, and I even re-instantiated the anim in Godot and tried tweaking the frames and rotation there. No success.

          but the fact that the animation works in Blender, Unity, and Unreal, leads me to think there is a bug.

          Yes, precisely 🙂 If it were looping wrongly anywhere else, I'd be the one to blame, but since it works everywhere else, I see this as a Godot problem.

          Biggest proof that it just works everywhere else. The wheel animation for my game trailer (starts at 0:11) is EXACTLY the same unaltered in UE, it's the same mesh and NLA action. For the sample project that I gave above I just removed the other parts of the mesh.

              Is that your game? I really do love Brazilian street food. I bet you'll make a over 1 Brazilian dollars!!!

                alfredbaudisch

                Self-interview:

                If it works in UE and you even made the trailer in UE, why insist to make it work in Godot? Why not just keep using UE?

                Because I made the trailer in UE and I'm trying to make the game in Godot - but Godot is pushing me away with issues like this that are common sense in other engines.

                  cybereality Yes, it is my game! The trailer exploded in Brazil, I went all over the news in all of BR's tech and gaming websites and even had many interviews about it!

                    Logically that makes sense, but I wonder if it should still be considered a bug since it differs from other 3D packages. Also, in Blender, you can set a particular timetime region to export, so you don't need to change the animation.

                      It looks like the old looping clip problem with Adobe After Effect CS6. Users have a similar work around of adding extra frame after the last frame. It was never fix so I believe if they were to fix it would break other stuffs so they just left it. 😆

                      cybereality but I wonder if it should still be considered a bug

                      Functionally? No. UX? Maybe. Personally I prefer starting from 0 but consistency with other tools has it's value.

                          cybereality in Blender, you can set a particular timetime region to export, so you don't need to change the animation.

                          Yes, that's what I did instead of changing the animations.

                          Megalomaniak UX? Maybe. Personally I prefer starting from 0 but consistency with other tools has it's value.

                          I think consistency with other tools is more important than trying to force Godot's weird ways. After all, no project is made in a single tool, plus there's millions of existing assets that can be re-used in the pipeline.

                                Maybe a good compromise would be a text box on the import settings that says start frame (default on 0) but you could put in 1 if you are using assets from other engines.

                                alfredbaudisch Godot's weird way

                                I wouldn't really say it's a "godot's weird way", there are other animation tools that typically start from frame 0 but most of these are more sim oriented. Frame 0 is then used to initialize the sim and frame 1 is meant to be the first relevant 'animation frame'.

                                But this is also to say that there really should be a way to have that frame 0 but set the animation track to start at and loop to frame 1. IMO.

                                    Megalomaniak But this is also to say that there really should be a way to have that frame 0 but set the animation track to start at and loop to frame 1. IMO.

                                    Yeah, this would be the better idea. If you can set a start and end frame for the animation on the timeline.

                                      Megalomaniak you're right and I agree with providing both options and your suggestion would be very welcoming 🙂

                                      But when I say "Godot's weird way", it's the same that used to be with Blender - it had its own way of doing everything completely different from every other package, basically nothing up to 2.79 Blender was consistent with any other software out there - it was weird in that sense (and I used it from 2.4 to 2.79 massively).

                                      Then with Blender 2.8 they decided to add compatibility modes and get consistent with the "industry" and now Blender is getting (or already is) "industry standard" too (i.e. wide adoption, more funding, etc).

                                      Imagine being able to rely on the Unity's Asset Store and UE's Marketplace and seamless dragging and dropping the assets into Godot? But 90% of the time everything breaks due to these incompatible decisions (and I'm talking about just re-using FBX files and the like).