1. #1

    Physics joint problems

    I have a section where I shoot the bike/rider straight up in the air, and at a certain point they pass through an area trigger. I want that area trigger to turn physics on for a large "plank" so that it springs up beneath the rider near the max height.

    The problem is, I've set everything up, but the physics joint motor seems to want to apply force on the bottom edge of my plank, instead of where the actual joint is located. For instance, if I want the bottom to spring up, with the joint at the top, the motor pushes against the joint.

    If I set it up so the top part of the plank rotates down, it works fine (but knocks the bike and rider out of the way). If I try to set it up so the bottom rotates, it doesn't behave right.

    I've done this exact setup in a track I did in Evolution, but it's not working in Fusion.

    This video shows what I mean. I temporarily turned physics for both objects on, rather than having them enabled by the area trigger, so I could easily show the difference. I've double checked all numbers and they are all the exact same.

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  2. #2
    Wraath's Avatar Member
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    I cant think of anything else other than change that big grey object for another piece or deco only it. I have noticed that some larger objects have invisible parts which can be ridden over and it may be interfering with the joint. Can you disable collision in Fusion?
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  3. #3
    Yeah, you can. The motor and force for the pivot joint seemed to want to rotate the pieces about their respective centers of mass, rather than at the place where the actual joint was. I tested it by moving the slender piece out in the middle of nowhere, and the piece rotated around in a large circle with the center being the joint, and the radius connected to the center of mass of the plank. It just feels weird, so I'm not sure what, if anything, I'm doing wrong. This is for PS4, by the way. And Evolution was running on my xbox 360.

    I found a workaround, but it's really awkward and not nearly as pretty.
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  4. #4
    mutetus's Avatar Trials Developer
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    Are you sure the joint is not turned 90 degrees in the wrong way? That setup should work as it is with the default hinge settings but the only thing I could see in the video is that the joint keeps hitting the upper limit and pivoting in the wrong direction, but couldn't really figure out what's exactly happening in there without seeing the joint parameters.
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  5. #5
    See if this helps. It's the exact same situation (except collision is turned off for the big piece) from above, just on a brand new track. And again, all the numbers match from what I did in Trials Evo (which worked exactly as intended), but I don't have a capture card for my 360 so it's video would be really bad for me to show settings.

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  6. #6
    I too am having a problem with physics joints:



    If anyone could help that would be appreciated.
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  7. #7
    mutetus's Avatar Trials Developer
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    lmxloco, turn the pivot 180 degrees on Y axis(around the red ring) instead of X, turning it that way doesn't change the rotation.

    Apdenton, Turn physics off to move objects with OPE.
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  8. #8
    Originally Posted by mutetus Go to original post
    Apdenton, Turn physics off from to move objects with OPE.
    I just had another look to how I had it setup in evo. Object b/target 2 (the object getting OPE'd) had physics off, object a/target 1 physics on. Just tried in Fusion but to no avail.

    Edit: Just had another look at my setup in evo. With that physics change (object 2 off) they are now exactly the same yet it doesn't work in Fusion.

    Edit2: Oh bollocks, fixed it. Dumb mistake. I'll look for another 3 hours before requesting help next time
    Thanks for your help anyhow.
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  9. #9
    Originally Posted by mutetus Go to original post
    lmxloco, turn the pivot 180 degrees on Y axis(around the red ring) instead of X, turning it that way doesn't change the rotation.
    Wow. I feel like a complete idiot for not seeing that.

    Thank you very much for your help!
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