Vision callback functionsA child script, or a customization script can include a vision callback function, when associated with a vision sensor. When present for a given vision sensor, then the system will call the callback function everytime a new image was acquired or applied, allowing the user to perform image processing. This is the case with following API functions: sim.handleVisionSensor, sim.checkVisionSensor, sim.checkVisionSensorEx, sim.setVisionSensorImage, and sim.setVisionSensorCharImage. Some conditions apply as to the location of the vision callback function: normally, it should be inside of a customization script, or a non-threaded child script. However, if the triggering API function (e.g. sim.handleVisionSensor) is called from within of a threaded child script, then the vision callback function should also be located in the threaded child script. If a vision callback function is present in a non-threaded child script as well as in a customization script, both attached to the vision sensor, then the child script will be called first, and the customization script second. Following represents an empty vision callback function: function sysCall_vision(inData) -- We have: -- inData.handle : the handle of the vision sensor. -- inData.resolution : the x/y resolution of the vision sensor -- inData.clippingPlanes : the near and far clipping planes of the vision sensor -- inData.viewAngle : the view angle of the vision sensor (if in persp. proj. mode) -- inData.orthoSize : the ortho size of the vision sensor (if in orth. proj. mode) -- inData.perspectiveOperation : true if the sensor is in persp. proj. mode local outData={} outData.trigger=false -- true if the sensor should trigger outData.packedPackets={} -- a table of packed packets. Can be accessed via e.g. sim.readVisionSensor return outData end Image processing can be performed by using various API functions. The vision plugin exports a few very simple image processing functions. Many more image processing functions are supported via the image plugin (OpenCV wrapper). Following represents a simple edge detection vision callback function, that triggers and returns a packet of data (based on the vision plugin functions): function sysCall_vision(inData) simVision.sensorImgToWorkImg(inData.handle) simVision.edgeDetectionOnWorkImg(inData.handle,0.1) simVision.workImgToSensorImg(inData.handle) local outData={} outData.trigger=true local packetData={1.0,42.123,129.3} outData.packedPackets={sim.packFloatTable(packetData)} return outData end Following represents a vision callback function, that draws a circle onto the acquired image (based on the image plugin functions): function sysCall_vision(inData) local imgHandle=simIM.readFromVisionSensor(inData.handle) local center={inData.resolution[1]/2,inData.resolution[2]/2} local radius=(inData.resolution[1]+inData.resolution[2])/8 simIM.circle(imgHandle,center,radius,{255,0,255},4) simIM.writeToVisionSensor(imgHandle,inData.handle) simIM.destroy(imgHandle) end Recommended topics |