centre of bottom

[studi...@iol.it]

Ciao, 

I shot a pano inside, I'm trying to reposition the camera as close as possible to the previous position.

Find attached the screenshot from P2Vr bottom view:

Can I assume the centre of the cross is the centre of the bottom? Can I use that point to try to reposition the camera close to the previous one?

Otherwise, any other suggestion?

Thnkx

roberto

[John Houghton]

On Tuesday, September 5, 2023 at 4:05:11 PM UTC+1 studi...@iol.it wrote:

Can I assume the centre of the cross is the centre of the bottom? Can I use that point to try to reposition the camera close to the previous one?

Roberto, Yes, your assumption is correct, provided the panorama has been levelled to get all the vertical features properly vertical.  The entrance pupil of the lens (aka no-parallax point) should be positioned directly above that cross.

John

[studi...@iol.it]

thank you so much, John.....

If I can ask....

Also finding the correct point on the floor, maybe I'm not sure of the highness of the camera:

I made a test but, of course, using the offset filter, I can fix the horizontal shift, not the vertical one.

Is there a way to decide if the camera must be higher or lower compared to the original one?

 

thnkx

roberto

 

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[John Houghton]

Roberto,  I presume you have access to the room in question, in which case you could measure accurately the distance taken up by a row of tiles.  Then load your equirectangular image into PTGui and apply pitch -90 with the numerical transform option.  Rotate the image to get the measured strip of tiles horizontal in the window (rectilinear projection. Then measure the angle of view in the panorama editor window  by adjusting the width of the window to the measured strip and read off the hfov from the Projection option on the fly-out menu of the Panorama Editor window. (NB. click on the width parameter to see the accurate value including the decimal point etc).  Then it's just simple trigonometry to work out the height.  Your guess is as good as mine as to the accuracy this might deliver.  Otherwise, there may be vertical parallax visible in the panorama between near and far features, which you could attempt to replicate.

John