Home Forums Software Development Finding the Depth for the Active Display Area Calculator Reply To: Finding the Depth for the Active Display Area Calculator


I’m sorry to post here from an old post, I actually haven’t found how to set up a new topic, and maybe it’s just better to do it here.

I try to understand the content of the paremeters of the tools (the html page referred above) but I just dont get it. Actually, one of them is really unclear to me: the vertical distance optical center to mid front.

I wanted to test it a bit, and to do so, I have made as if the eye tracker’s front face was parallal to the display and aligned with the middle and bottom of the display. Therefore, in that case, all offset values in step 2 and 3 are 0.
Then, I only change the default value (using EyeX for instance) of the mounting angle, in the step 4, to 0 since it’s parralal.
If the display were 200*50 (it is just an example), then I would expect to get the following values:
Top left: (-100.0, 60.0, 0) mm
Top right: (100.0, 60.0, 0) mm
Bottom left: (-100.0, 10.0, 0) mm
because it is clearly said in the SDK documentation that the active display coordinates are to be expressed in the UCS, which has an origine at the centre of the front face of the eye tracker.

But, instead, I have :
Top left: (-100.0, 60.0, 10.3) mm
Top right: (100.0, 60.0, 10.3) mm
Bottom left: (-100.0, 10.0, 10.3) mm.
I can see here the effect of the vertical distance optical center to mid front on the depth, but I just dont understand what it can be. If it is a depth, why it’s not “included” in the the value of the depth in step 3 ?

As far as I can understand, only the display dimensions, offsets from step 2 and 3, the distance between the top edge of the eye tracker and the centre (“distance mid from to top front” in step 4) and the mounting angle should be needed… Where do I get it wrong ?

Thanks a lot for your help,

Best regards,