Re: [Pipmak-Users] Hotspot maps

[Christian W. <cwa...@gm...>]

> Right now I can't figure out how the hotspot maps map to a cubic  
> panorama.
> As far as I can tell, the hotspot is a single image file.
> Does this image somehow map to an unwrapped cube?

That's a good question, and the answer unfortunately isn't in the  
documentation shipped with 0.2.0 yet. Here's what I wrote about it in  
the current CVS version of the documentation:

> Hotspot maps are 256-color (indexed) images. Color index 0 means  
> background, color index 1 is the first hotspot, index 2 the second  
> etc. The actual colors don’t matter, so you can use any color palette.  
> A particularly suitable palette with easily distinguishable colors is  
> included in the source distribution of Pipmak in hotspot-palette.gif  
> in the extras folder.
> For slide nodes, the image is stretched to cover the whole slide (it  
> need not have the same size or aspect ratio).
> For panoramic nodes, the hotspot maps are equirectangular, that means  
> that azimuth (0..360°) and elevation (-90°..90°) in the panorama are  
> mapped to the horizontal and vertical axes in the image. The horizon  
> in the panorama is mapped to the vertically centered horizontal line  
> in the image, the point directly above the viewer (zenith) is  
> stretched out along the whole top edge of the image, and  
> correspondingly the point directly below (nadir) along the bottom  
> edge. For example, if your hotspot map is 360 × 180 pixels, then the  
> pixel at (68, 52) is what you see 38° (= 90° − 52°) above the horizon  
> after you turn 68° to the right from the initial orientation. See the  
> pipmak.saveequirect function in section 3.2.8 for a preliminary hack  
> to help you draw equirectangular hotspot maps.

Does that help? (If not, please tell me what points are not clear, so  
that I can improve the documentation.)

Here's how I answered this question before (and maybe other useful  
hints):  
<http://www.mystcommunity.com/board/index.php? 
showtopic=15120&view=findpost&p=241469>

Equirectangular hotspot maps have the advantage of consisting of only  
one file. Cubic hotspot maps, i.e. six images that coincide with the  
face images, are on the to-do list, but aren't implemented yet.

I don't have time for preparing a full release that would include the  
updated documentation right now, but I'll probably post just the  
documentation somewhere on the Pipmak home page in a few days. I'll  
announce that here.

  -Christian