I am doing a tutorial for a 3D game of cars driving through a city. The apart from a blank road surface level tile all the tiles have a lower road surface and an upper pavement surface.
My problem is that traffic cones and fire hydrants are all sunk half-way into either surface causing problems when my car hits them. With the cylindrical collision shape enclosing all of the mesh when my car hits these objects they drop down out of sight. If I raise the collision shape half way or so up the mesh the cones pop up onto the surface if I pass near them. If I hit the cones they get knocked around onto the road or pavement surface, but they don't fly around like they would if they were resting on the surface as they should be doing. Why isn't the collision happening on the upper surfaces from the start? The fire hydrants are distributed the same way, but I can't hit them because the game freezes instantly at the start. Your help appreciated.