No More Cracks
A feature added to DirectX 7 is vertex blending, which is hadware accelerated via the GeForce 256. Vertex blending is a technique used to smooth out the appearance of two adjoining pieces of geometry.
Vertex blending has a variety of uses in the 3D world, one of which is creating characters whose body parts are seamlessly joined together, such as arms and legs.
Developers no longer have to create objects that have cracked seams as depicted in the left image. By using DirectX 7, they will now be able to provide seamless surfaces such as those shown in the right image.