- I have a Pano2VR project with input of six cube faces of 2000x2000

pixels each.

I want to create a transformation to an angular map "little planet"

(circular).

How do I calculate the maximum resolution possible given the size of the

cube faces?

Many thanks,

Robert

--

Robert Slade, Photographer

Manor Photography 07890 564889

http://www.manor-photography.com - Robert Slade wrote:

> I have a Pano2VR project with input of six cube faces of 2000x2000

Just an estimate: 2000px cube face width has the same resolution as

> pixels each.

>

> I want to create a transformation to an angular map "little planet"

> (circular).

>

> How do I calculate the maximum resolution possible given the size of the

> cube faces?

6282px equirectangular width. You can do "little planet" with a 360°

fisheye mapping which would be the same width as the equirect. It very

much looks as if Pano2VR uses this mapping.

However, the better mapping for "little planet" is stereographic, which

stretches the outer regions. PTGui f.e. suggest 300° for "little planet"

with about 14000px for a 6000px wide input equirect...

Perhaps you find some more info following the links on

http://wiki.panotools.org/Stereographic_Projection.

best regards

--

Erik Krause

http://www.erik-krause.de - Erik Krause wrote:

> However, the better mapping for "little planet" is stereographic, which

The formula is quite simple:

> stretches the outer regions. PTGui f.e. suggest 300° for "little planet"

> with about 14000px for a 6000px wide input equirect...

2 * equirect width * tan(FoV/4) / pi

The result is the stereographic image width and "FoV" is the angle of

the desired field of view of the stereographic image.

However, Pano2VR most likely doesn't use this mapping but the fisheye

one, where the output image width is the same as the equirect image width.

best regards

--

Erik Krause

http://www.erik-krause.de