Problems with pressure groups

Discussion in 'Content Creation' started by TrackpadUser, Aug 9, 2020.

  1. TrackpadUser

    TrackpadUser
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    Joined:
    Aug 24, 2019
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    I've recently released an amphibious vehicle in beamNG, which involves using pressure groups to make it float.

    The issue however, is that pressure groups seem to be incredibly finicky. The wiki suggest the following to avoid issues:
    The current repo version of the Labrador beaver involves a "flotation box" shaped like this:
    upload_2020-8-9_14-34-30.png

    I thought this would be "uniform" enough to avoid ghost forces, however after looking at feedback, it seems that there is a force pinning the vehicle in the ground, which is visible if you use the weight pad. There are also weird problems if you enter the water upside down, where it seems to get accelerated toward the bottom until it rights itself again.

    So to try and fix those issues, I've made the "flotation box" into a very even box shape with only 90 degree angles.
    upload_2020-8-9_14-36-11.png
    And I still get a pretty significant force pinning it into the ground, in addition to the other issues I had previously.
    upload_2020-8-9_14-43-57.png

    However, even if I could find the perfect shape that avoids all forces, that brings us to the second issue, which is deformation of the flotation box.

    While one could possibly make a flotation box that's the perfect shape to avoid ghost forces, a fun aspect of the soft body physics is the ability to have things deform on impact.

    On the beaver this causes some "interesting" behaviors. Neilogical's video showcases this fairly well.


    However, that issue isn't limited to the Beaver, and the barrel, which is the only rigid vanilla object which I know uses pressure groups (exlcuding tires), also has some ghost forces issues if you deform it, where it starts to spin by itself.


    So I was wondering if there was either some very specific way to avoid issues, or if we could possibly get an alternative to pressure groups when it comes to making things float.
     

    Attached Files:

    • upload_2020-8-9_14-45-35.png
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