299 user defined apriltag sizes

[nampereira]

Close #299

[nampereira]

The ARENA apriltag detector and pose solver assumes the tag size from tag id, as shown in the table.

Tag ID Range	Tag Size (mm)
[0,150]	150
[151,300]	100
[301,450]	50
[451,586]	20

To use apriltag markers in your scene with sizes different from the table above, add an ARMarker component to an object in your scene (by doing this, the position component of this object indicates the position of the marker in the scene) and its size (see example figure).

The example shows setting the size (50mm) of marker 0 (marker id):

This is the entire json payload for the object where the above example ARMarker component was added. Note that the position component indicates the marker is the origin (0,0,0 x,y,z) of the scene.

{
  "object_id": "origin_box",
  "persist": true,
  "type": "object",
  "action": "update",
  "data": {
    "object_type": "box",
    "depth": 0.05,
    "height": 0.01,
    "width": 0.05,
    "material": {
      "color": "#7f7f7f",
      "transparent": true,
      "opacity": 0.5
    },
    "position": {
      "x": 0,
      "y": 0,
      "z": 0
    },
    "rotation": {
      "x": 0,
      "y": 0,
      "z": 0
    },
    "armarker": {
      "lat": 40.4432,
      "lon": 79.9428,
      "markerid": "0",
      "markertype": "apriltag_36h11",
      "size": 50,
      "ele": 200
    }
  }
}