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Wednesday, September 19th 2018, 3:26pm

"Hotspot-image" following sphere of pano. How to do this?


As we know, pano has a apperance of a sphere: in fact we have spherical coordinates when insert some vectored hotspots in pano : Atv, Ath (If you put an hotspot in every degree of that coordinate system you'll see exatly a sphere...)
But I expect that when I insert a large image as hotspot, that image follows the skin of this sphere too. But not.
Actualy in the "hotspot-image" exists only a "lead point" that is linked with that coordinates: a corner or the center according with our choose.
Surely, "hotspot-image" appears distorced, with a good perspective effects, but that distortion is not exactly the distortion of the image covering sphere surface (look at examples, at bottom).

I expect that "every pixel of that hotspot image" follow the spherical skin of pano but it doesn't happen.
Does exist a method that allows the hotpot image having the same apearence of "the portion of spherical layer"?

Hotspot image, as is possible to do now by editors

Hotspot image as I would to create. As you can see, image is following the sphere.

Thank you in advance


This post has been edited 1 times, last edit by "AntNuz" (Sep 19th 2018, 8:47pm)


Monday, September 24th 2018, 6:36pm


sorry, but krpano currently supports only rectilinear/flat hotspot images.

Hotspots with spherical or cylindrical projection are very uncommon...
What would be usage case?
Using crops from a spherical image as hotspots?

Best regards,


Wednesday, September 26th 2018, 4:55pm

Editing Code fo Make an HotSpot Image "part of sphere"

Dear Klaus, thanks for your answer. When the inserted image as hotspot is a "small" image, it appears relatevely as a part of pano. But, in some cases, image that we need to insert is very large. Large as 1/3 of max circunference of sphere, or larger, for example.In that case, should be interesting that image follow the geometry of sphere, as something painted on the concave skin of sphere ("Sistina Chapel", or Dome effect).Till now, allowed images are only flat or linear . It means that a large image crosses the sphere as a chord and not as part of concave skin (Look at link Does exist a metod to images gain the effect of being part of a sphere (look at simulation ) ?Actualy, exist a way to control this (apparent) sphere, and this is the coordinate spherical system of krpano ambient (Atv, Ath, Depth etc..). Theorically, it should be enought transfer every pixels of image in his relative shperical coordinate.... But how it is possible do this in KRPANO? Perhaps, editing code?We know the mathematic behind this conversion, but we don't know how to apply this in KRPANO. Is it possible by editing code?
Thanks a lot, againAntonio



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Location: Lisbon

Occupation: Programmer/analyst

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Wednesday, September 26th 2018, 10:14pm

i've seen this around here

dynamically changing cubefaces while rotating

if i can find it i'll post a link


Friday, September 28th 2018, 4:29pm

very interesting.
But we need to add an image that is not a sphere on another sphere, but "a part of a sphere" on the pano sphere.
Imagine, for example, if we can insert a PNG, representing numbs, on sky of pano and we want this png covering the skin curve of sphere...

or some others examples
(we would have this effect on desktop version pano too)


This post has been edited 1 times, last edit by "AntNuz" (Sep 28th 2018, 4:42pm)


Thursday, October 4th 2018, 10:44am

dynamically changing cubefaces while rotating

Here an old example for such:
720 degree pano


Monday, June 22nd 2020, 3:30pm

Has been any developments in this matter?

I'd like to make a map visible in VR and it would be much more natural if the map appeared as if it followed the curvature of krpano's sphere
But images in hotspots appear as if they were just planes tangent to the point of the sphere defined by the coordinates of the hotspot

Anyone has figured out how to this?
Or maybe krpano has developed a way to handle this?

Thanks in advance