This is INFURIATINGLY frustrating!!! There is a hack to get around this where I attach a ton of other invisible objects to my shape, but duplication becomes a major issue and workflow is severely stunted. Why can't I make the collision shapes I need??
Good question actually, I just bought Buildbox and started making a motocross demo just to get a feel of the software, and the first limitation I saw is this one. Last time I made a game it was 2014 in Flash with box2d, it had unlimited features, like soft shapes, buoyancy on water, etc'. I wish Buildbox had these out of the box.... could be pretty cool. But seems like it uses its own engine and not some open source feature rich like box2d... I wonder why? Probably some licensing limitations (like if box2d does not allow itself to be re-sold in other products)
Hi, knowing that collision shapes must be convex, you can try combing objects with 0 opacity to achieve the collision shape you need. I hope this helps.
Because it is not so difficult to have convex 2D collision model, rather than concave collision. Nice paper about efficient 2D polygon collision here: http://wscg.zcu.cz/wscg2004/Papers_2004_Full/B83.pdf