ubular: .07; segmentsTubular: 32">
        </a-mixin>

        <!-- Layout mixins. -->
        <a-mixin id="column"
                  geometry="primitive: box; depth: .75; height: 1.2; width: .75"
                  material="color: #FFF" position="0 .6 0"></a-mixin>
        <a-mixin id="column-bottom" geometry="primitive: box; depth: 1;
                                              height: .1; width: 1;"
                 material="color: #FFF" position="0 .1 0">
        </a-mixin>
        <a-mixin id="colum