sketchucation logo sketchucation
    • Login
    🛣️ Road Profile Builder | Generate roads, curbs and pavements easily Download

    C shaped object collision geometry how to?

    scheduled pinned locked moved SketchyPhysics
    2 Posts 2 Posters 7.0k Views 2 Watching
    loading-more-posts
    • oldest-to-newest
    • newest-to-oldest
    • most-votes
    reply
    • reply-as-topic
    guest-login-reply
    deleted-message
    • Y Offline
      youthreewire
      last edited by

      HEllo,

      I am trying to simulate the collision of a C shaped object (like in the attached picture). What shall I do to make sketchyphysics generate a collision geometry in the shape of a C.I am using sketchy physics 3.2 and google sketchup 7.
      c shape collision geometry.jpg

      one-reply-to-this-post last-reply-time reply quote 0
      • A Offline
        Anton_S
        last edited by

        To make any concave, movable shape in SP you need to create a group consisting of sub-convex groups. Your top level group should be set to Compound2 shape. Your sub-groups are by default considered as a Convexhull, however, you can specify their shape otherwise.

        To make your "C" group have a concave collision you have to break it down to convex groups, group them together, and make the parent group a Compound2 shape.

        To set group shape, pick any desired group(s), right click (enter context menu), and select SketchyPhysics -> Shape -> Compound2.

        Note that SketchyPhysics 3.2 doesn't have a Compound2 shape. To produce a concave shape in SP3.2, associate the parent group as a Default shape and sub-groups as Convexhull shapes. Groups of Default shapes can be associated in later SP versions, but the problem is that Default shape doesn't have a true centre of mass, whereas Compound2 shape does have a true centre of mass. That's why I suggest using Compound2 over Default shape if you're using SP3.6.

        Anyway, here is a sample, which is compatible with SP3.2 or higher:


        movable convave shape.skp

        one-reply-to-this-post last-reply-time reply quote 0
        • 1 / 1
        • first-post
          last-post
        Buy SketchPlus
        Buy SUbD
        Buy WrapR
        Buy eBook
        Buy Modelur
        Buy Vertex Tools
        Buy SketchCuisine
        Buy FormFonts

        Advertisement