Draws a single colored circle. A BonVision primitive that draws a 2-dimensional circular/oval region.


DrawCircle displays a circle/oval of specified size, at the defined location. The colour, location and size can all be controlled by the experiment.


Best used with SphereMapping transformed coordinate frame


  • Needs DrawStimulus (the tag for rendering a frame) as an input to be able to run

  • LocationX: x coordinate (this is in the units of the viewport?) (Default: 0)
  • LocationY: y coordinate (this is in the units of the viewport?) (Default: 0)
  • Diameter: Diameter of the Circle
  • ColorR: Value of Red (0 to 1)
  • ColorG: Value of Green (0 to 1)
  • ColorB: Value of Blue (0 to 1)
  • ColorA: Value of Alpha mask or tranparency (0: Transparent to 1:Opague; Default: 1)
  • MinorAxis???: Can we have an oval?


  • This can be an end node
  • All the properties that are externalised can be sent forward as outputs.