Spring constraint patch submitted

Video on Vimeo

The spring constraint can be used to get wobbly/bouncy effects on bone chains such as antennas etc. The target bone (the one carrying the constraint) copies the transforms of the source bone and adds the spring effect to it. It also uses a buffer that allows skipping and backwards scrubbing while maintaining consistency, and as the buffer is saved along with the blender file, it should work on a renderfarm too (however i did not actually test that).

There is a windows build for testing available for download here: http://graphicall.org/builds/builds/showbuild.php?action=show&id=1698

An example blend-file: http://ivogrigull.com/blender25/spring_demo.blend

Link to the patch in the tracker: http://projects.blender.org/tracker/index.php?func=detail&aid=26825&group_id=9&atid=127

One issue is interactivity though. It is not possible to pose/animate a chain predictably while the constraint is active, because the buffers of the chain’s spring constraints would need to be updated on the fly. I think this goes beyond my coding abilities and understanding of the animation system code. And i gues it would be relatively slow too. Nevertheless i believe it is a great help for animators and certainly nice to have, even if he needs to enable/disable in order to edit it. I suggest to use a python driver expression to control all bones’ constraints at once to ease the pain. In the current state it needs to be considered as a post effect.

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2 Responses to Spring constraint patch submitted

  1. Ciriaco says:

    Hi, great work!!
    Is it possible to apply Spring constraint on the scale of an object or the movement?
    for toon-style animation

  2. blendman says:


    It’s very interesting :)
    Will it be release in the official release of blender ?

    Thank you very for your work !