We hope to get an early release soon. Then everyone can be a beta tester! We only have private builds to make sure things are working well enough to make it public. I've never understood private betas. If people want to try your stuff and report issues, limiting it to a small group means fewer reports.

3rd party runtimes can implement their own physics. Note that if they use code from our official Spine Runtimes then they must attach our Spine Runtimes License Agreement to their runtime. If that is agreeable, porting will be quite easy. If it's not, building their own physics will be a little tricky. At any rate, we'll likely port it quickly to all the runtimes we support.

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I know of only a single 3rd party clean-room runtime, and they are in the process of switching over to our official runtimes. I'd hardly call that an issue to worry about.

    We won't be giving any other access for early testing until it's fully working properly. I know it seems like it's already usable, but there are things not working right and things missing. We don't need it to be 100% finished before starting the beta, but unfortunately it's still not ready. We're working hard to get it there ASAP!

    @LeonNeol The runtime is spine-libgdx. The entire Spine editor is built on top of libgdx and uses the spine-libgdx runtime. That's why spine-libgdx is always updated with new features first. The code is already up on GitHub in our spine-runtimes repository in the 4.2-beta branch, though the code pushed there typically lags behind our actual development slightly.

      Nate
      I mean the 3rd party clean-room runtime Mario mentioned

        Oh, sorry I misunderstood. I'm not sure which Mario meant. I believe the Defold game toolkit used to have their own clean room runtime for Spine data, but they later abandoned it in favor of our official runtimes.

        The runtimes are a lot of effort for us to build and maintain. It would be even more effort for a third party to do it while also keeping it a clean room implementation. Every new Spine version that adds new features means more work for a third party runtime, else their users fall behind in functionality. It makes a lot of sense to use our runtimes and let us do that hard work. The trade off is that then you are subject to our runtime's licensing terms, but I hope you find them flexible enough to not be a problem.

        6 days later

        Any chance of collision support with this new physics system. It seems like other tools do this using circle / sphere and capsule colliders that attach to the simulated bone.

        One thing with collision support though is that if you wanted to integrate it with the game world it would be nice to have a function or a callback that could give a list of collider's on the spine asset. Then we could give back a list with whether or not the collider is colliding with the world along with the velocity. So Spine could apply the collision. I am sure there are other ways to do this but this is what came to mind first.

        It would also be nice if colliders could be freestanding and not attached to any bone or be attached to a separate skeleton that can then interact with other skeletons physics. That way if you want to have multiple things interacting with each other you could.

        If there is no chance for a collision system built in perhaps it would be possible to add the ability to attach colliders to the bones in Spine Editor. As well as keeping the physics API open enough so that it could be implemented by the developer of games should they require it.

        I am aware of the bounding box attachment but a polygon would be less efficient to compute compared to a sphere / circle or capsule.

        4.2 is looking awesome, excited to give it a try. Thanks for all the work for this release.

        • Nate replied to this.
          12 days later

          It's almost November, and I might be looking forward to coming to the forum every day to see if Spine4.2 has released a beta version. Waiting is really a long process

          @Nate Hi Nate, for example if (in mono game/xna) I would like to make a tree moved by the wind, can it be done?

          Nate Mister Nate, maybe we can already try the beta version? We will look for mistakes together... ))

            Hello, how is the progress of beta version? We really hope to get some latest related information

            We are sorry that we cannot give you all a clear answer on when we will be able to release 4.2-beta. All we can say is that we will release it as soon as possible. Since it will only be a beta, we cannot answer exactly what features will be available at that time, and some features that were available at the time of the beta may be removed before the official release. (Although major features are rarely removed, minor features may be removed or merged into another feature). So trying to get more information at this point may only confuse you, and we hope you understand that we cannot update information often because we do not want to confuse you.

            nate066 We won't have colliders in 4.2 but we're not counting it out for the future. I can say that we don't want to build an extensive physics system. That would be fun, but it's difficult and we already have lots of animation tools to build! Our physics systems aren't intended to be used for an entire game, just to give dynamics for your animations without using a lot of CPU. That said we do want to have a way to bridge the gap between animation physics and game world physics. Often that can be done by moving or following a bone. Collisions are harder. Circle bounding boxes could be a first step, as you mentioned.

            Getting ahead of myself, we have plans for mesh physics after 4.2. That is where a mesh reacts to bone movement using physics. We have a prototype for that, here's an example:

            Image removed due to the lack of support for HTTPS. | Show Anyway

            Only the bones are animated. The fish image is the mesh and bends in the simple way you'd expect. The wireframe is the mesh with mesh physics applied. It's somewhat subtle in this example, but you can see the dynamic movement in the mesh. All that movement comes from the simple bone animation and didn't need to be animated by hand! You will also be able to have some of the mesh's bones move from the mesh physics, giving you enormous power.

            It's super cool, but it does use a lot of CPU. We usually try to make things very efficient but some features like clipping or mesh physics require more processing and care needs to be taken with how they are used. In comparison, the physics in 4.2 are relatively cheap and don't use much CPU.

            Anyway, we continue to work on 4.2 every day. I know the wait sucks. We want to get it released as much as you want to use it, but it has to meet some minimum requirements first. Even when it feels like we're so very close, it takes a lot of time to iron out all the details, even for a beta release.

              8 days later

              The 4.2 beta has started! 💃 We'll do a proper announcement, but for now those of you who are paying attention can give a try!

                Nate we're already trying))

                  Oh, Nate, the new version of the laptop is really amazing. Would you consider adding a storage preset function for future physical functions so that changing parameters can be faster

                    blgjdg We considered presets, but the sliders usually require so much fiddling it's not much of a time saver. Copy/paste between constraints might be enough.

                        Nate
                        May I ask how to use 'deterministic'?
                        I need backing system, for loop video.

                          When Deterministic is checked, the pose you see in the editor is the result of applying the animation and physics many times from frame 0 to the current frame. This gives you a consistent pose for any given frame. Since posing physics always starts at the first frame of the animation, you can scrub back and forth on the timeline and see the physics rewind. Also you can animate more easily, without physics floating your bones all around, but while still having effects from physics.

                          It will cause a jump at the end of looping animations. For loops you may want to leave Deterministic unchecked.

                          The downside to checking Deterministic is that Spine has to do a lot of work to pose each frame, and the work increases the higher the frame is on the timeline. On my quite powerful computer, my Spine editor starts to drop below 60 FPS at about frame 1100 (~37 seconds of animation) on a skeleton with 52 physics constraints, all set to 60 FPS. At runtime or when Deterministic is off, physics are very efficient. I have never see a framerate drop from physics alone, even with 100 physics constraints. Deterministic causes a frame rate drop because it's both applying the animation and physics many hundreds or thousands of times for every editor frame.

                          Deterministic only affects the editor. At runtime your code can "fast forward" physics like this, if you want. Your code can also control when physics are reset, or you can reset physics by keying the reset with the Reset and Reset All buttons in the Spine editor.