ZBrush is a powerful tool for 3D modeling, and sometimes you may need to create a symmetrical model by mirroring a copy of the OBJ file. Here's how you can easily mirror copy ZBrush OBJ files:

Step 1: Open the OBJ file in ZBrush. You can import your OBJ file by clicking on the 'Tool' palette and selecting 'Import'.

Step 2: Once the OBJ file is loaded, go to the 'Geometry' sub-palette and select the 'Modify Topology' section.

Step 3: In the 'Modify Topology' section, find the 'Mirror and Weld' button and click on it. This action will create a mirrored copy of the OBJ file, making it symmetrical along the specified axis.

Step 4: You can choose the axis for mirroring by selecting the 'X', 'Y', or 'Z' option in the 'Mirror and Weld' settings.

Step 5: Once the mirroring process is completed, you can then make further adjustments to the mirrored copy as needed.

By following these simple steps, you can easily mirror copy ZBrush OBJ files for symmetrical 3D modeling. This technique can be incredibly useful for creating balanced and precise 3D models for various projects. Happy modeling!