<contact name="name">
  <!-- Exactly 1 of -->
  <!-- Set the link used to build the reference frame
       In the first case, the position of the points below are expressed in the
       link frame.

       In the second case, the position of the points below are expressed in the
       frame of the "index_collision_object"th collision body in the link. If
       you have only one body, then set it to zero. This is a convenient way of
       of defining surfaces on a particular body.
       -->
    <link name="link_name" />
    <link name="link_name" index="index_collision_object" />

  <!-- Exactly 1 -->
    <!-- Sequence of 3D points expressed in the frame defined above -->
    <point>-0.025 -0.025 -0.025   -0.025 0.025 -0.025   -0.025 -0.025 0.025   -0.025 0.025 0.025 </point>

    <!-- Sequence of planar shape.
         Shapes are defined by a sequence of points to be connected (consecutively).
         For a shape defined by N points, N+1 values must be provided in this tag:
         N iPoint_1 ... iPoint_N

         WARNING: Shapes 3 0 1 2 and 3 0 2 1 are different because their respective orientations are opposites.
         firstSegment ^ secondSegment must points outside the object -->
    <shape> 3 0 2 1 3 2 1 3</shape>

    <!-- DEPRECATED -->
    <!-- Sequence of triangles, where a triangle is 3 point indexes in the above list of points
         WARNING: Triangle 0 1 2 and 0 2 1 are different because their respective orientations are opposites
         01 ^ 02 points outside the object -->
    <triangle> 0 2 1 2 1 3</triangle>
</contact>
