Proximity sensor detection parameter dialog

The proximity sensor detection parameter dialog is part of the proximity sensor properties. The dialog displays various detection parameters of the last selected proximity sensor.

[Proximity sensor detection parameter dialog]


  • Front / back face detection: the user can decide which side of a triangle the sensor will see and detect. Front faces appear as blue, back faces appear as red in the triangle edit mode.
  • Fast detection (approximate): when selected, the detection process will be faster, but not exact anymore (i.e. the detected point might not be the closest point).
  • Limited angle detection: when selected, a maximum angle between the detection ray and an object's face normal vector can be specified. This is a useful feature when modeling ultrasonic proximity sensors. Ultrasonic proximity sensors normally cannot see surfaces that don't face the sensor enough. When enabled and the maximum angle is small, calculation time can be drastically increased. See also the Occlusion check item below.
  • [Limited angle detection principle. Yellow arrows indicate surfaces normal vectors. Maximum angle is 30° (for example)]


    [Two identical proximity sensors configurations. Only one proximity sensor has the limited angle detection turned on (right)]


  • Occlusion check: when the sensor operates in the limited angle detection mode, then it can happen that hidden surfaces get detected. Enable this item to avoid this, however calculation time might drastically increase. When quick calculations and occlusion checks are required, try using randomized ray type proximity sensors.
  • Don't allow detections if distance smaller than: some sensors have a minimum detection distance (e.g. ultrasonic sensors) from which the sensor won't be operating anymore (i.e. the object to be detected is too close from the sensor). To model this behavior, one could simply set an offset for the detection volume, but by doing so the sensor will still be able to detect other objects that are located farther away. A real sensor would have its "view field" blocked by the closer object and not detect anything. This can be modeled by indicating a minimum detection distance (a mask distance) that, if undershot, would simply disable detection.
  • [Two proximity sensors, one without mask distance (left), the other with mask distance (right)]


  • Randomized ray detection: randomized ray detection is available only for randomized ray type proximity sensors. During randomized ray detection, a ray will sweep a cone-shaped volume in a random fashion. You can specify how many random rays the sensor should check (ray count), and how many ray detections are required to trigger the sensor (ray detections count for triggering).

  • Recommended topics

  • Proximity sensors
  • Proximits sensor types and mode of operation
  • Proximity sensor properties
  • Proximity sensor volume dialog