Hi Thomas,
This is a question of QTVR format. I added "horizonposition" parameter to define the horizon in a cylindrical pano, in the same way that PTViewer. This value is 50% if the camera was leveled and the cylinder is not cut in the top or botton, but this value can change if the stitched cylinder is cut. I saw that QT reads this value from the MOV file, but I don't know where is this value to read it in DevalVR. Does Pano2QTVR support this feature?
Horizon Position value
oh.... you mean you can create shifted cylinders like PTViewer? Never tried this but it sounds logical..... the values should be different tilt-min and tilt-max values, so that tilt-min!=tilt-max. Do you have a demo image + PTViewer file at hand? If so, can you drop me an email or send me the link because then I should be able to create the same parameter as for PTViewer.
MfG, Thomas
Hi Thomas,
Yes, this makes sense.
I don't have any example, but you can create a demo. Cut a cylindrical pano in the top or in the bottom and the cylinder will show with a curvature. If you cut in the top, the new horizon position must be less than 50% of the new image.
Thank you Thomas!
Yes, this makes sense.
I don't have any example, but you can create a demo. Cut a cylindrical pano in the top or in the bottom and the cylinder will show with a curvature. If you cut in the top, the new horizon position must be less than 50% of the new image.
Thank you Thomas!
I discovered the exact formula used by QuickTime to calculate "horizonposition" value:
horizonposition = 50.0 + (( maxTilt + minTilt ) * 100.0 ) / ( defaultFieldOfView + maxTilt - minTilt );
I found another pano made with Pano2qtvr 1.6 that has some black pixel lines in the bottom of cylinder. In this case, the minTilt and maxTilt values are equal, but QT player cuts some degrees in the bottom to never show the black pixels. Where Pano2qtvr saves this info? (I can send you an example if you want)
regards!
horizonposition = 50.0 + (( maxTilt + minTilt ) * 100.0 ) / ( defaultFieldOfView + maxTilt - minTilt );
I found another pano made with Pano2qtvr 1.6 that has some black pixel lines in the bottom of cylinder. In this case, the minTilt and maxTilt values are equal, but QT player cuts some degrees in the bottom to never show the black pixels. Where Pano2qtvr saves this info? (I can send you an example if you want)
regards!
There is an additional atom "tcon" (for tilt constrain) where you can further limit the viewing area.
There are also "pcon" and "fcon" atoms that are evaluated on top of the limits in the "pdat" atom. As I was thinking that tilt-min and tilt-max need to be symmetric I used "tcon" to limit the view. The unsymmetrical approach would save memory of course...
There are also "pcon" and "fcon" atoms that are evaluated on top of the limits in the "pdat" atom. As I was thinking that tilt-min and tilt-max need to be symmetric I used "tcon" to limit the view. The unsymmetrical approach would save memory of course...
MfG, Thomas
Thank you for the info
I can't find any info about 'tcon, 'pcon' and 'fcon' atoms, I have the "QT file format" and "QT API reference" documents, but there is not any info about the fields of these atoms. Where do you find the info about QT format?
I searched in Apple page too, but without success
I can't find any info about 'tcon, 'pcon' and 'fcon' atoms, I have the "QT file format" and "QT API reference" documents, but there is not any info about the fields of these atoms. Where do you find the info about QT format?
I searched in Apple page too, but without success
Yeah.... this is Apple style. The only reference I found is a little sample code from Apple. If you look into the file you should see the structure. It's a QTAtom with 2 float values: Min and Max.
MfG, Thomas