Search Unity

animated physics workflow: how to get an animated spinning panels FBX to apply force to a rigidbody?

Discussion in 'Physics' started by racarate, May 8, 2019.

  1. racarate

    racarate

    Joined:
    Jul 14, 2012
    Posts:
    62
    I previously asked an elaborate question about animate physics as applied to an imported FBX file, but I have simplified the troublesome part and now have a much simpler question:

    Does a kinematic rigidbody (moving via animate physics) take into account the mass of the things that it hits?

    I was hoping to have an animated paddle hit a low-mass sphere and a high-mass sphere and have them behave differently.

    But it seems as if the kinematic rigidbody (moving via animate physics) is just applying a velocity that is independent of the mass of the thing it is colliding with, no matter what kind of physics material is applied.

    Details:
    paddle = kinematic rigidbody with animate physics enabled
    low-mass sphere = dynamic rigidbody with mass 1
    high-mass sphere = dynamic rigidbody with mass 10000
    all objects = physics material with both friction 10 and bounciness 1
     
    Last edited: May 8, 2019
    racarate, May 8, 2019
    #1

  2. racarate

    racarate

    Joined:
    Jul 14, 2012
    Posts:
    62
    Is there another way I can ask this question? I'm really stumped, but maybe this is so simple a question that the answer is obvious? Appreciate any help!
     
    racarate, May 12, 2019
    #2

  3. Edy

    Edy

    Joined:
    Jun 3, 2010
    Posts:
    2,510
    No. Kinematic rigidbodies will move no matter what's on their way.
     
    Edy, May 13, 2019
    #3
    racarate likes this.

  4. racarate

    racarate

    Joined:
    Jul 14, 2012
    Posts:
    62
    Thank you for taking the time to respond!

    Shouldn't the spheres that the kinematic sphere hits take mass into account?

    I am expecting the kinematic rigidbodies to move no matter what is in their way, but I was hoping that it would apply realistic forces to the non-kinematic rigidbodies it collides with. Those collisions don't seem to be taking the mass of the non-kinematic rigidbodies into account.
     
    racarate, May 14, 2019
    #4

  5. racarate

    racarate

    Joined:
    Jul 14, 2012
    Posts:
    62
    Ok, I guess since there is no answer to my question that this isn't actually supposed to work -- kinematic rigid bodies aren't actually supposed to receive mass-based forces from non-kinematic rigid bodies controlled by an animation... even when animate physics is taken into account.

    How do people work around this? Are you supposed to somehow calculate the velocity of the non-kinematic body and then just use Rigidbody.AddForce?
     
    racarate, May 21, 2019
    #5