COLLADA Exporter for Unity Developers in the Unity Asset Store - Game Development Tool Essentials - page 92

The COLLADA Exporter in Depth
From the top, here is the exporter explained. The first parameter, the export choice, may be either “Entire Scene”
(the default when nothing is selected by the user), or you may select one or several objects to export by choosing
“Selection Only.” The “Selection Only” option only appears in this dialog box if you have selected an object to export
from your scene or project window.
Header Information
The first set of options is the header information, where you can fill in the names of the authors, comments, and
copyright information; all these are optional. This comprises the header of the COLLADA header <asset> information.
Then you have the length unit name and length unit size in meters, which default to “meter” and “1,” respectively.
To change the unit, just type over these values. If you want to use inches, for example, you can enter “inch” in the unit
name box and “0.0254” in the unit size box. No actual conversion is performed by the exporter, as the application
importing the COLLADA document uses that information to conform all imported files to the same dimensions.
Texture Options
In the copy textures option, if you select “Copy Images,” all the images used by the exported Asset will be stored in
subdirectories provided in the Texture folder. The default name for the Texture folder is “textures,” but you can
change that to whatever you want.
The default conversion choice for images is “Convert All Images To PNG.” The exporter will create either RGB
(24) or RGBA (32) textures (see an example of “texture” in Figure 8-5 , taken from the well-known COLLADA Duck)
depending on whether the internal format in Unity has transparency. Another option is “Convert Images To
PNG 24;” this will convert all images to RGB (24) .png , thus removing the alpha/transparency information. This
option is useful for preventing undesired transparency information from being transferred when the alpha channel
is not used for transparency.
Figure 8-5. COLLADA Duck “texture”
The last option is “Do Not Convert Images.” In this case, the original images will be copied into the Texture
folder directly. The issue with this option is that most COLLADA importers may not recognize formats such as .psd .
Whichever choice is made, the COLLADA document will reference the image file that was copied or converted. If
“Texture copy” is set to “Do Not Copy Images,” the images won't be copied, but the conversion choice parameter