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How to check if colliders overlap?

Discussion in '2D' started by catalincraciun, Apr 7, 2015.

  1. catalincraciun

    catalincraciun

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    If you have to colliders (let's say an BoxCollider2D and a CircleCollider2D), how do you check if these colliders are overlapping? Colliders methods don't seem to work... Both are triggers.
     
    catalincraciun, Apr 7, 2015
    #1

  2. MelvMay

    MelvMay

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    MelvMay, Apr 8, 2015
    #2
    nodnarbisc, SoftWillowProductions, dnadkin_gamepoint and 3 others like this.

  3. catalincraciun

    catalincraciun

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    Hello, thanks for your response. The problem is that I want to check if a collider hits any other collider. But I have solved that with Box Cast, thanks anyway.
     
    catalincraciun, Apr 8, 2015
    #3

  4. MelvMay

    MelvMay

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    ... and that's exactly what those methods check for; if the specified colliders are touching.
     
    MelvMay, Apr 8, 2015
    #4

  5. catalincraciun

    catalincraciun

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    Sorry, I have forgotten to mention that I don't know the other collider. I have a tag, let's say "Box", and I want to check if a collider is touching any collider attached to any box.
     
    catalincraciun, Apr 10, 2015
    #5

  6. MelvMay

    MelvMay

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    The physics system is layer-based so if you use layers then you can use 'Collider2D.IsTouchingLayers()' to see if your collider is touching anything on specific layer(s). It doesn't however tell you what is colliding which is obviously where 'OverlapArea' can help when you're not interesting in casting a box over a distance.
     
    MelvMay, Apr 10, 2015
    #6
    theANMATOR2b likes this.

  7. amarnaman

    amarnaman

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    That's really useful but what about if you want to check if two 3D colliders are overlapping?
     
    amarnaman, Jan 23, 2017
    #7

  8. MelvMay

    MelvMay

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    I don't think there's the equivalent test in 3D physics apart from the ones I presume you've already look at in Physics.
     
    MelvMay, Jan 23, 2017
    #8

  9. amarnaman

    amarnaman

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    Thanks for the suggestion (obvious I know)! I hadn't spotted Physics.OverlapBox before and it worked just fine. It was a bit trickier to use than I'd thought and I cheated slightly since it was returning more hits than I'd expected (I think it was the extents I was using but it's hard to tell).
     
    amarnaman, Jan 23, 2017
    #9

  10. maarten_unity795

    maarten_unity795

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    Sorry for digging up an old post but for anyone looking for that now and wants a simple answer: 
    Collider.Bounds.Intersects(OtherCollider.bounds);
     
    maarten_unity795, Jun 14, 2022
    #10
    Joy-less likes this.

  11. MelvMay

    MelvMay

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    Well unfortunately that isn't a good way to do it unless you want a very rough check. At best they will overlap but it'll also result in saying they might overlap because "Bounds" is an AABB.

    For 3D you might be better off using something like Physics.ComputePenetration and looking for overlap.

    This was a question about 2D though.
     
    MelvMay, Jun 14, 2022
    #11
    stefanob likes this.