Changing origin of the floor

Question

Is it possible to change the origin of a floor from center to say left upper corner in Webots? For exmaple the size of then rectangular arena is 20x20 and I want to set its origin from 0,0 to 10,10

Answer 1

Yes, you can do that by creating your own proto file. I would recommend you to start from an existing proto, for example, WEBOTS_HOME/projects/objects/floors/protos/Floor.proto. Copy and rename this file to MyFloor.proto for example and edit it to change the coordinates of the IndexedFaceSet node. Typically you will have to replace:

        geometry IndexedFaceSet {
          coord Coordinate {
            point [
              %{= -(size.x / 2) }% 0 %{= -(size.y / 2) }%
              %{= size.x / 2 }% 0 %{= -(size.y / 2) }%
              %{= -(size.x / 2) }% 0 %{= size.y / 2 }%
              %{= size.x / 2 }% 0 %{= size.y / 2 }%
            ]
          }

by:

        geometry IndexedFaceSet {
          coord Coordinate {
            point [
              0 0 0
              %{= size.x }% 0 0
              0 0 %{= size.y }%
              %{= size.x }% 0 %{= size.y }%
            ]
          }

That will move the floor origin at a corner of the floor. Also, the boundingObject should be updated so that the floor looks nicer when selected. Replace:

    boundingObject Plane {
      size IS size
    }

by:

    boundingObject Transform {
      translation %{= size.x / 2 }% 0 %{= size.y / 2 }%
      children Plane {
        size IS size
      }
    }