Specular map

[batonrye]

I'd like to make a material that has varied brightness of specular highlights, determined by a texture. (Note: i don't need to change the degree of specularity, just its color, or brightness) an example would be, say, shiny metal with dull rusty spots.

Not knowing too much about shaders yet, what would be the best (most efficient) way to achieve this?

It would be neat to a have method of generally filtering effects like specular highlighs and reflections (ie: only puddles in a road reflecting) I've searched the net, and gone through many example shaders, but have not seen effects like these (except in published games )

[RyanN]

right here:
http://www.ogre3d.org/phpBB2/viewtopic.php?t=8914

[batonrye]

awesome -just what i was looking for! thanks a ton - i had searched but was unable to find