One of the final pieces of the puzzle regarding Dreamcast mipmapping was finally solved! Dreamcast had a feature called “Mipmap D-Adjust” which in practice is nearly identical to mipmap LOD bias, with the only difference being that it works with a factor (* d-adjust) instead of a bias (+ lod bias).

Flyinghead came up with the implementation, it has been merged and should be in the nightlies later today.

We made two comparisons here – one with Daytona USA 2001, the other with V-Rally 2 –

Daytona USA 2001

Please check the link down below so you can see the difference –

http://www.framecompare.com/image-compare/screenshotcomparison/JCBBCNNU

The tree on the left is more detailed now in the far distance, same for the public next to it.

V-Rally 2

Here the difference is even more pronounced – please check the link down below so you can see the difference –

http://www.framecompare.com/image-compare/screenshotcomparison/DZLDLNNX

The road looks a bit blocky and low-detailed with mipmap D-Adjust off, while it looks normally with it turned on.