rotary control knob 3d model

Create a photorealistic 3D rotary control knob matching the reference: a large circular brushed dark-gunmetal aluminum knob, viewed straight from the front with a very slight top-down perspective. The face is gently convex with fine radial brushed-metal grain, subtle anisotropic reflections, and a soft central highlight. Add a narrow polished metallic bevel around the outer edge, surrounded by a thick black knurled/ridged grip ring with many small evenly spaced tactile teeth. Include a short, thick, rounded white indicator line near the lower-left edge of the knob face, slightly inset from the rim. The knob should feel heavy, precision-machined, premium medical/industrial equipment quality. Mount it flush into a dark charcoal brushed-metal control panel. Realistic PBR materials, accurate metallic roughness, soft studio lighting, subtle contact shadow and ambient occlusion, realistic depth and edge reflections, no text, no numbers, no scale markings, no extra controls.