Pretty much the mist doesn’t work, and any texture with alpha enabled turn s blackish and there are white lines around areas with other objects. Such as the lines surrounded the tree’s bark, where the leaves are overlaying the ground, and otherwise.
Are you using BI or cycles?
Internal, I haven’t done much with cycles. Is there a way to fix it with internal?
Are you using a different texture for the alpha or are you using a texture with an alpha channel.
If the former, you should make sure to uncheck the ‘color’ field in the texture panels since you only want it to determine the alpha.
Will that fix the white boarders?
I believe the white borders are a different issue. If you’re making any use of the compositor here, make sure you have the premul option checked when combining layers.
The leaves are pretty basic, like using the alpha slider in the properties/textures, and enabling transparency int eh materials. Is there a better way to do this? That may fix the issue?
Are the color channel pixels that are supposed to be in alpha white by any chance?
The white doesn’t show on every border, it could be a mismatch between the desired alpha fringes and the actual map.
How can I fix it?
You might try to generate a new alpha map for it (either extracting from color information or by manual alpha painting).
Another thing might be to extend the margins of the color map.