Import and export >
Import a model from ZBrush

You can import models sculpted using Pixologic™ ZBrush® into Mudbox. This approach requires that the ZBrush model have UV texture coordinates and that you export two .obj files from ZBrush: One from the base subdivision level, and the second from the highest subdivision level containing the high resolution sculpted detail. You import these two files into Mudbox after first recreating the same subdivision level structure as your ZBrush file.

NoteRecreating the subdivision level structure when importing models from other sculpting applications such as ZBrush is the recommended technique for recreating the model in Mudbox. This approach lets you create multiple subdivision levels and sculpt layers and provides improved interactive performance compared to importing only the high resolution ZBrush model as the base level in Mudbox.

1. Launch ZBrush and open the file you want to export to Mudbox.
   NoteThe model must have UVs prior to being exported to Mudbox. If the ZBrush model does not have UV texture coordinates, you can create them in ZBrush using the Tool:Texture subpalette and selecting the AUVTiles button while displaying the lowest subdivision level (Level 1). For further information on exporting from ZBrush, refer to the ZBrush online documentation.
2. In the Tool:Geometry subpalette, click the Lower Res button (Hotkey: Shift + D) until ZBrush displays the lowest subdivision level for the model (Level 1).
3. In the Tool:Export subpalette ensure that the following options are turned on, then click Export.
   - Txr: Ensures that UV texture coordinates are exported.
   - Qud: Ensures that existing quads (four-sided polygons) do not get triangulated during export.
   - Mrg: Ensures any non-welded UVs are merged (critical if you plan to paint on the model in Mudbox).
4. Type a name for the model then press Enter (for example, <filename_level1.obj>).
5. In the Tool:Geometry subpalette, click the Higher Res button (Hotkey:D) until you display the highest subdivision level for the model.
6. Using the Tool:Export subpalette, export the high resolution model using the same export settings described earlier.
7. Type a name for the second file that differentiates it from the low res file you output for the base subdivision level (for example, <filename_level5.obj>).
8. Exit ZBrush.
9. Launch Mudbox and open the low res file you saved from the base subdivision level in ZBrush. For example, <filename_level1.obj>.
10. Using Mesh > Add New Subdivision Level (Hotkey: Shift + D), create the same number of subdivision levels as the original model contained in ZBrush. (In this example, four additional levels.)

    Keep the highest subdivision level selected for the next step.

    NoteZBrush and Mudbox use a different layer numbering start point. That is, the base subdivision level in Mudbox is named Level 0, while in ZBrush it is named Level 1. Keep this in mind when recreating subdivision levels when importing from ZBrush or keep track of the number of polygon faces as you subdivide.
11. With the highest subdivision level selected, select File > Import As Layer
12. Select the high resolution file for import (for example, filename_level5.obj), then set the following options in the Import Options window that appears, and then click OK.
    - Match by: UV Position
    - Tolerance: 0.0001
      NoteIf there are noticeable differences between the original ZBrush model and what appears in Mudbox after import (small holes or protruding spikes on the model) it indicates there isn’t an accurate correlation between the models. You may want to experiment by importing the model again and further reducing the UV import tolerance.

    This imports the higher subdivision level model and recreates the highest subdivision level of the ZBrush model in Mudbox. When you step down using the Page Down key, you will have all of the sculpted information on the lower subdivision levels.