Reverse Parenting of a Point to Another Point

I have a situation where I want to be able to keyframe the rotation of a point and have another point in the exact same place rotate the opposite way. So for example, if I keyframe the Parent Point to rotate from 0 to 20 degrees on the Z-Axis, the Parented Point (located in the same place as the first point) rotates automatically from 0 to -20 degrees on the Z-Axis.

Of course, I can simple copy the keyframes from the Parent Point to the Other Point and change the signs, but it would be nice to only have to keyframe the Master Parent Point and the Other Point would procedurally rotate in reverse automatically. After putting some serious thought into this, I cannot come up with a way to do this. Any ideas?


  • If this were Maya, I'd start talking about things like orient constraints, or perhaps connections via math nodes. However, HitFilm doesn't currently have that kind of between-layer connection capability, and parenting definitely won't help.  Like you, I've been trying to think outside the box about ways to maybe use a mix of parenting and targeting to hack this, but nothing is coming to me.

  • I don't have a solution now, but I can tell you that this kind of behavior will become incredibly easy to do very soon.

  • @inScapeDigital can you tell us how soon? 

  • @Andersen01498 Probably not.  Releases of upcoming software usually have very strict NDAs tied to them, even for mentioning the release date.  I'm sure all will be revealed in due time.

  • @jsbarrett I know, I just got a little too excited for this upcoming release.  Its not nice to tease people.  :) 

  • @inScapeDigital Thank you for that... I can be patient! :)

  • I have come up with a workable solution! My request has to do with a tutorial that I am working on. I may go ahead and wait until the the next version of HitFilm comes out to see how that version can help. If anyone is interested, I would be happy to post my solution.

  • If you've got a solution that works, I'd love to hear it.  The hinted solution that @inScapeDigital mentioned may end up being a Pro-only feature for all we know, so Express users would definitely benefit from what you've worked out.

  • The tutorial I am working on is a Pro tutorial rigging a model. My technique can be (sort of) done in Express without models. It is not a complete solution, but it is complete enough to work for what I want to do!

    I am rigging an X-Wing from Star Wars from beginning to end. Part of the tutorial will be to be able to open and close the wings with one keyframe animation. There are four wings and they each open up at the same time with two going up and two going down. Therefore with regard to the 3D Points that each of the four wings are parented to, two of those points would rotate in one direction and two would rotate in the other direction. Of course, I can simply animate the wings individually, but in the Star Wars universe, I have never seen the wings of an X-Wing fighter move individually. If you would never have that happen, then it would make sense to tie all four wings to one control point and only need to make one animation change.

    Logically, I have slimmed down my rig to the least number of parts that I would need, so I have even removed two of the points that control the wings. In other words, I am parenting two wings to each of only two points. Then I just need to be able to animate them with one keyframe animation. That is the solution that I have worked out.

    The reason I call it a "partial" solution is because the wings only need to rotate approximately twenty or twenty-five degree, so I don't need to create a full rotation. The solution that I came up with can do what I want, but not a full rotation.

    I you are interested, I would be still happy to post it! Ultimately, it may end up in the tutorial, or it may not, depending on potential features of HitFilm Pro 2018.

  • As I said before, I'm sure that some benefit can be gained from sharing your current version. I'd love to know more about it!

  • I will do it! :)

  • @HitFilmSensei Check out the "Rotate by Layer" Behavior in the new HitFilm Pro.

  •  @HitfilmSensei, so ... show us how you did it in Express? ;)

  • @inScapeDigital Thank you for remembering my question! I figured it out when I watched the video from @Triem23.

    @Palacono My reason for needing this was to animate an X-Wing model. So therefore, my solution is actually in HitFilm Pro 2017, although it can be translated to Express. The solution will be in this Monday's HitFilm Sensei tutorial, which I filmed earlier this week. I was not privy to the 6th version of the software until today, when I purchased it.

    Of course, using the "Rotate by Layer" Behavior would make it even easier, so I may have to add an addendum at a later date.

  • @HitfilmSensei note you'll see rotate by layer in the video I have scheduled for next week--Improved Camera Jibs, which also has my variation on your technique for 2017 users. Now you know what I was talking about when I told you I was going to have an updated jib video last month...

    Can I respectfully ask you let me air before you jump on that technique as I recorded  a month ago? :) 

  • @jsbarrett and @Palacono Here is my tutorial on rigging an X-Wing. In it contains my solution to animating all four wings with one controller.

    @Triem23, next week I will add an addendum showing how to do it much more quickly and easily in HitFilm Version 6. I am waiting until after your video releases as you have requested.

  • @HitfilmSensei That, my friend, is a really elegant solution.  Bravo!

  • Already said this in your thread, but it warrants saying again: That. Was. Awesome. :D

  • +1000 (if there is such a thing)

  • Thanks everyone! Next week, I am adding to this video talking about adding motion blurs and the easier way to animate the wings using the new "Rotate by Layer" Behavior.

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