APT v1.0 Notions
A virtual tour is an immersive and interactive image presentation. This kind of presentation is particularly adapted for displaying panoramas covering a very large field of view.
This allows the user to visualize the panoramas using a more realistic projection mode and enables him to interact with graphical elements and/or information.
Most image formats are accepted by Autopano Tour.
The panorama must be a spherical projection (also called equirectangular). When added to the project every panorama is by default treated as a 360 degree image by Autopano Tour. For partial panoramas, it is necessary to set the correct FOVs covered by the panorama. If the panorama was generated using Autopano Pro or Autopano Giga and assuming that the image format used can carry EXIF data (JPEG or TIFF or example) this information will automatically be inserted into Autopano Tour.
If you wish to import non stitched images you can use the tool described on the following web page to calculate the FOV of you equipment. http://www.bobatkins.com/photography/technical/field_of_view.html
Just as described in the Understanding Projecting Modes page, the Spherical projection tends to lead to some degree of image distortion (straight lines tend to get bents for example). When creating a Virtual Tour the panoramas are re-projected in a 3D environment in order to mimic the original shooting environment. The user is relocated at the center of the scene in order to eliminate (to the best possible extend) the distortions coming from 2D flattening.
Two main approaches are then possible: locate the user at the center of a sphere or at the center of a cube. The 3D modeling of a sphere being less accurate that the one of a cube we tend to prefer the cube method for full 360 degrees panoramas. From a technical stand point, a Planar re-projection (maintains straight lines) is performed for each face of the cube. Re-projecting on a sphere is used for partial panoramas in order to avoid storing useless data (cube faces with few data).
Hotspots are graphical areas allowing for user interactivity.
Two types of hotspots are available:
- Polygonal hotspots: represented by a polygonal area within the panorama.
- Point hotspots: represented by a graphical object (image or animation) centered around a punctual location within the panorama.
Four interactions are possible:
- Open another panorama.
- Open a web page (in a web browser, outside the Virtual Tour).
- Display an HTML page (inside the Virtual Tour).
- Display a graphical object (image or animation).
Other graphical element can also be added to the final Virtual Tour:
- Logo: to sign your work.
- Menu: to simplify the navigation within the Virtual Tour.
- Drop down List: to quickly switch between views (panoramas) available within the Virtual Tour
(it is necessary to purchase a KRPano license in order to use this option).
- Lens Flare: lets you graphically, and dynamically, simulate a lens flare effect.