If you do not own an OKM detector but have a .3d or .gps file you want to view, the official software might be locked. You can try generic 3D viewing apps, though they may not interpret the metal detector data correctly:
Suddenly, the screen flickered. The 3D model began to shift, the shapes morphing from geometric cubes into something resembling a seated figure. His Bluetooth headset crackled with a sound like a heavy door scraping against stone. Elias looked down at the ground, then back at the screen. The figure on the visualizer had stood up. OKM Android Apps okm visualizer 3d for android free download link
If you simply want to explore 3D visualization or ground scanning concepts: If you do not own an OKM detector but have a