Fog & Masking

Hi all,

I’m working on an OpenGL game with 2D and 3D graphics, I use 2D
sprites in a 3D environment.
To render the 2D sprites I use masking (using blended textures).
Now I want to add fog to the scenery with the OpenGl std. fog.
When I blend the sprites with the fogged landscape I see the bounding
box of the initialy blended textures, I mean with this that the
transparency of the sprite disappears and give very ugly results.

Does anyone know howto get around this problem?

Thanx in advance,

Daniel Palomo van Es.

you could “cut out” parts of your sprites,i.e. making parts of it totally transparent(alpha value),i think the technique is called color-keying