Seasonal display of objects

[rhumbaflappy]

Currently, we can alter the display object textures via a lua script for object models according to month of the year. And we can control the visibility of objects in a similar manner, using the modeldef.xml file during compilation.

What we do not have is a method to control either the texture or appearance of a model according to the seasons.bgl, which defines spring, summer, fall, winter and hard winter. Adding this capability to the model or texturing would greatly simplify the ability of an object to be displayed anywhere in the world with the correct appearance, for the correct season.

[rhumbaflappy]

And would not autogen definitions be greatly simplified if one object is needed for seasonal display, rather than 5 objects currently needed?