Defining camera field of view



  • Hi,

    I'm trying to define a fisheye camera with a horizontal field of view of 190 degrees. As far as I can tell the hFOV and vFOV properties have no effect on the output. The only property that changes the field of view is focalLength. Based on a visual inspection it looks like this works for our 60 degree cameras with a focal length of 5.8mm but not for the 190 degree cameras with a focal length of 2.09mm.

    I'm using the following sensor definition for the fisheye camera.

    <sensor name="API Fisheye Camera" sensorType="APICameraSensor" preview="CameraBig.png" 
    	objectAsset="CameraObject" sampleRate="30" portNumber="0" quality="15" tags="ANVEL_Common">
    	<lens resolutionX="1928" resolutionY="1208" ccdWidth="5.784" ccdHeight="3.624" focalLength="2.09" hFOV=190" vFOV="100" >
    		<position x="0.13" y="0.0" z="0"/>
    		<orientation w="1.0" x="0.0" y="0.0" z="0.0"/>
    	</lens>
    </sensor>
    

    Is there something I'm doing wrong with the definition of the vFOV and hFOV? If not is there a formula for the camera model that's implemented in Anvel that I can use to calculate the focal length for a 190 degree camera?

    Also, on the Sensor Definitions wiki page it says the focal length is defined in meters but based on the default sensor definition it looks like it's defined in millimeters.

    Thanks



  • @zen_perception,

    Currently, the Sample Camera and API Camera are able to achieve a wide-angle view, similar to a fisheye lens but without the distortion. We were able to get it up to about 180 degrees horizontal, which is unfortunately the limitation of the rendering engine. As you noticed, there is an issue with setting the hFOV and vFOV properties directly, but the ccdWidth, ccdHeight, and FocalLength combine to determine the FOV. If you define the camera as so:

    <sensor name="API Fisheye Camera" sensorType="APICameraSensor" preview="CameraBig.png" 
    	objectAsset="CameraObject" sampleRate="30" portNumber="0" quality="15" tags="ANVEL_Common">
    	<lens resolutionX="1928" resolutionY="1208" ccdWidth="200" ccdHeight="4.99" focalLength="2.09" >
    		<position x="0.13" y="0.0" z="0"/>
    		<orientation w="1.0" x="0.0" y="0.0" z="0.0"/>
    	</lens>
    </sensor>	
    

    This screen capture includes a standard SampleCamera aligned with a FisheyeCamera to show the same scene from two different lens views.

    0_1522435852579_fisheye_demo.png

    Click on the image to view the properties of the camera.

    Thank you for your question, and hopefully this gets you closer to what you're looking for. True fisheye lenses would be a great addition to a future version of ANVEL, so we'll keep it in mind!

    Regards,
    The ANVEL Team


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