rock wall panel 3d model

Create a 3D model of a side wall panel for the inside of a display case. Size: 12 cm wide and 20 cm high. The panel should look like a natural cave wall made of rough rock, shaped by erosion over time. Keep the top, bottom, left, and right edge areas relatively flat and shallow, with only subtle texture near the borders. Do not create a raised frame or thick protruding edges around the panel. Concentrate most of the rocky relief, cracks, layered stone, and uneven natural formations in the central area. The center may have moderate bumps, shallow recesses, and organic rock variation, but the transitions should feel smooth and natural. Avoid symmetry, repeated patterns, sharp isolated spikes, or artificial shapes. The back surface should be flat. Keep the outer shape a clean vertical rectangle. Make it a single solid object suitable for 3D printing. Style: realistic dark gray and brown cave rock. No characters, swords, text, or extra objects.