|  | The spherical lens computes equirectangular images. These 
                  images with a strange look have always a height equal to the 
                  half of their width (2/1 proportions) and are useful to generate 
                  a panorama viewable with Quicktime VR, JavaScript tools 
                  like Panolens or Three.js,... | 
             
              |  | In the Lights category of the catalog, there are 
                  some special lights called Light source and represented 
                  by a light bulb icon. These light sources have no physical 3D 
                  representation and can be seen in the 3D view only when selected, 
                  for feedback purpose. They are used only to enlighten the 3D 
                  view at the two best quality levels. Enlarging them will produce 
                  softer shadows. | 
             
              |  | At the two best quality levels, the color of the sun rays 
                  depends on the elevation of the sun in the sky at day time, 
                  and the sun doesn't produce light at night time. If you selected 
                  a color for the sky in the 3D view 
                  pane or if the current mode is Aerial view, a sky image 
                  computed according to the hour of the day is used for the rendering 
                  of the sky. If you chose a texture for the sky, that texture 
                  will always be used in Virtual visit mode whatever the 
                  selected hour. | 
             
              |  | If the computed image is all black, check whether the virtual 
                  observer is in a wall or not, and at night time, if there are 
                  some visible lights with a power greater than zero or if Add 
                  ceiling lights check box is selected. If the hour you entered 
                  is an hour of the day, check 
                  also if the geographical location and the time zone are consistent. 
                  Remember that when it's midday in Central European Time zone, 
                  it's still night time in California. | 
             
              |  | In Aerial view mode, the ceilings of the rooms are 
                  not seen. If you want to see them at the best two quality levels, 
                  you should use Virtual visit mode and elevate the point 
                  of view of the virtual visitor. | 
             
              |  | At a given quality level, you can still improve the image 
                  quality by choosing a bigger size for your image, then reducing 
                  the size of the computed image in an editor like The Gimp. | 
             
              |  | At the two best quality levels, the Renderer
                  dropdown list lets you choose the rendering engine that will compute the
                  image (not available on all systems). If you want to render images more quickly, 
                  try YafaRay and / or turn off some useless lights. An image of larger
                  dimensions will also take more time to be computed. | 
             
              |  | The Create photo and Create photos at points of view dialog boxes aren't modal. This means 
                  that it doesn't block the input in other windows and lets you 
                  modify your home or your point of view in the main window, while one of 
                  these dialog boxes is opened.  | 
             
              |  |  While a photo a is computed, changes made in your home 
                  won't affect the current rendering. |