knife handle 3d model

Create a 3D model of a premium custom knife handle only, no blade. Size: 150 mm long, 40 mm high, 36 mm wide. The handle is straight, symmetrical, clean and elegant, designed for SLA resin printing. Use an octagonal cross section along the whole length. If possible, gradually transition from octagonal at the front to hexagonal at the rear. Add a detailed organic relief inspired by dark wood grain struck by lightning: flowing grain lines, branching cracks, carved channels and layered ridges running mainly along the length. The texture should be dramatic but controlled, deep enough to be visible after printing, without random spikes or fantasy shapes. Include a front tang slot, closed rear end, and make the model a single solid watertight printable object. Dark ebony/resin appearance, premium custom knife style.