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Thread: Change Pivot Position Multiple Times In The Same Scene

  1. #1
    icon kid
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    Change Pivot Position Multiple Times In The Same Scene

    I already know how to properly center objects and to rig objects and nulls to effect the most needed rotational relationships among objects, but what I always thought you can't do is to have a null change position multiple times in the same scene without altering the Modeler object in any way. I saw a tutorial on it around a month ago. I didn't save it because I didn't think I would ever need this function, but now, I can't find that tutorial and it's needed. You sort of "re-assign" a pivot; -- you want it at one place from frame 0 to 10 (lets' say) and you want it to be somewhere else from frame 11 to 20.

  2. #2
    TrueArt Support
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    Add Null.
    Make Null parent of your real object.
    Change of position or rotation of Null, will also affect its children i.e. your mesh.

    Change of parameters of object, will be relative to parent i.e. Null item.

    Animate (in Graph Editor) Null and object item parameters independently.
    Last edited by Sensei; 10-28-2020 at 03:49 AM.

  3. #3
    icon kid
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    There's probably a hundred tutorials on this but it is not the issue. I'm talking about changing the position of an object's null on the fly in Layout -- and save the movement of the null to the scene file. Without this technique you have to go back to Modeler to change an object's pivot point and then refresh that object in Layout. If you want to move the pivot point five times in one scene then you have to do this process five times. When you save a scene, it doesn't remember that an object's pivot point moved five times because it's only going to load one original object file. The tutorial I'm talking about shows how to move an object's pivot point interactively in Layout and save these 'keyed' changes of position into the scene file. In that way you don't have keep going back and forth to Modeler to do edits and updating, nor do you have to do any fancy rigging of objects and nulls, nor making any edits to the original object file.

  4. #4
    Electron wrangler jwiede's Avatar
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    I think you're probably referring to this post, or possibly the very next one in that thread (which is essentially the technique Sensei described, assisted by Cyclist).

    It's kind of a bit roundabout in LW versus others, due to the inability to animate pivot independent of object, but either reassigned-parenting or single-null-parent+cyclist approaches will work for the classic rolling cube example.
    Last edited by jwiede; 10-28-2020 at 09:06 PM.
    John W.
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  5. #5
    LightWave Fan Boi
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    I'm not sure I fully understand what you're trying to achieve but here's what I think needs clarifying.

    Terms
    Pivot Point - Pivot points are part of all objects and are used as a point of reference to translate, rotate and scale an object's geometry in both Modeler and Layout.

    Pivot points can also be moved and rotated independently without affecting geometry in both Modeler and Layout, however, pivot points cannot be animated.

    Pivot points and Nulls are not the same thing.

    Nulls- Nulls are, to a large extent, treated in the same way as objects but without any geometry attached. They are generally utilised as controllers for various scene items and can be animated.

    I'm not sure if you're just getting your terms mixed up but from what you're saying it sounds like you want to move an object's pivot point in layout (which you can absolutely do) over time (which, to the best of my knowledge and according to the LightWave manual, you can't do) without affecting the geometry (why would you want to do that?).

    As I say, I'm not fully following your question, so forgive me if I've completely mis-interpreted what you're asking. If I've got this completely wrong, please do let me know where I made a wrong turn.

  6. #6
    icon kid
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    Thank you all who've responded. As jwiede has stated, you can not animate a pivot point -- which I've always believed to be true after twenty-five years of using Lightwave 3D. Somehow I must have been mistaken by one video presentation I saw recently which seemed to demonstrate otherwise. jwiede also asked why I wanted to use this technique. I'm making an animation of a wooden toy Frankenstein. As he walks he leans heavily from left right with each step, having a rigid body and knees that don't even bend. The idea was to have his pivot point at his left foot at the start and key it to his right foot at the frame when his right foot touches the floor so he can start leaning to the right on that foot -- and then just keep alternating. I actually tried this with the Move Pivot command in Layout but this didn't work -- Once the Move Pivot command is activated, the Create Key command becomes disabled -- DAMN! I'll just work around the situation like I've been doing for the last quarter century -- rigging nulls or stitching together separate scene files in order to get a continuous animation.

  7. #7
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    Going by your initial description, Icon Kid, I wondered if it might have been a video showing dynamic parenting, but after your recent post, I'm doubtful.
    I'm curious to know what technique or method it was that you'd seen.

  8. #8
    Electron wrangler jwiede's Avatar
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    Quote Originally Posted by icon kid View Post
    Thank you all who've responded. As jwiede has stated, you can not animate a pivot point -- which I've always believed to be true after twenty-five years of using Lightwave 3D. Somehow I must have been mistaken by one video presentation I saw recently which seemed to demonstrate otherwise. jwiede also asked why I wanted to use this technique. I'm making an animation of a wooden toy Frankenstein. As he walks he leans heavily from left right with each step, having a rigid body and knees that don't even bend. The idea was to have his pivot point at his left foot at the start and key it to his right foot at the frame when his right foot touches the floor so he can start leaning to the right on that foot -- and then just keep alternating. I actually tried this with the Move Pivot command in Layout but this didn't work -- Once the Move Pivot command is activated, the Create Key command becomes disabled -- DAMN! I'll just work around the situation like I've been doing for the last quarter century -- rigging nulls or stitching together separate scene files in order to get a continuous animation.
    Actually, that second example I mentioned above will do exactly what you need. The origin is basically centered in the body, and using cyclist, you make a null move in a bouncing kind of curved trajectory, similar to what the example shows, but the curved path alternates between being off-vertical leaning to the left, and off-vertical leaning to the right (it's one short repeating cycle for every step's transform, and another longer cycle for the L/R leaning and associated rotations at beginning and end of each side's step, hope that makes sense).

    When I get a chance, I'll see what example I can provide but doubt I'll have time to get to that before next Tue. If you need earlier, maybe someone else here gets what I'm describing and could provide one?
    Last edited by jwiede; 10-29-2020 at 08:49 PM.
    John W.
    LW2015.3UB/2019.1.5 on MacPro(12C/24T/10.13.6),64GB RAM, NV 980ti

  9. #9
    icon kid
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    Thanks to All.

    Thank you, jwiede, for the second link which introduced me to the "Parenter," which works, essentially, like the 'lost' video I once saw, and would satisfy the purpose of changing an object's pivot point in a contiguous scene. Parenter is a modifier that was added to LW version 2015, however, I'm still using LW 9.2. I am woefully past due for an upgrade. For now, I'll just complete my project using the old techniques. It's nice to know that Parenter will be waiting for me until I upgrade.

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