[Bf-cycles] Shading tangents patch (for the ward anisotropic closure)

[Mike Farnsworth]

I forgot to respond to the other issue.

On Wed, Mar 21, 2012 at 11:54 PM, Michael Fox <mfoxdogg at gmail.com> wrote:
> Thank you so much for working on this, there is some issues though
>
> http://mfoxdogg.com/development/cycles_ward_test.png
>
> firstly, it should not be darker then regular gloss

You're right...the darkness seems a little much.  I didn't actually
write the BRDF implementation; that was already there (Brecht adopted
it from the OSL Ward implementation I think).  The Ward BRDF may not
be properly energy-conserving.  If I had my choice, I think I would
implement Ashikhmin-Shirley or a D-BRDF variant of it instead of Ward,
as I know that one is pretty solid.

-Mike