The Gizmo3D Replacement IMM Workflow allows you to quickly swap a model with different models chosen from IMM brushes. By isolating individual elements, this workflow streamlines the process of modifying or replacing repeated assets, such as bolts, screws, or mechanical parts, without manually repositioning or realigning them.
This approach is beneficial for maintaining design consistency, refining details, and iterating on complex models efficiently. Since Gizmo3D aligns replacements automatically, artists can swap components while preserving orientation, making it a powerful tool for precise part replacement and rapid model adjustments.
Instructions to replace a single model with a single IMM brush component.
1. Select an IMM brush and choose a component from the IMM menu near the top of the screen.
2. Drag your pen on the model's surface and release to apply an insert component.
After step 2 is applied, ZBrush masks all other geometry except the inserted component after inserting a mesh component. This masking configuration is necessary for the following actions to work as intended.
3. Activate Gizmo3D, then select a different component from the active IMM brush menu or a different IMM brush.
Gizmo3D must be active for the replacement action to function.
The replacement IMM component aligns with Gizmo3D. If you haven't adjusted Gizmo3D's orientation after Step 1, the replacement component will maintain the same orientation in Step 3.
Instructions to replace multiple instances of the same model with a single IMM brush component.
This workflow applies only to objects within the same subtool.
1. Select an IMM brush that contains multiple components.
2. Apply a mix of unique IMM brush components, and duplicates of the same IMM brush component.
ZBrush masks all other geometry except the inserted component after inserting a mesh component.
3. Clear the Mask.
4. Open the Undo History menu, and tap the Marker (orange ribbon) to store essential model data for synchronicity.
5. Mask all but a model component that has duplicates with the same topology.
6. Activate Gizmo3D, and ensure its orientation is ideal for the replacement model.
For step 5, there are multiple ways to perform this action. Here is the most direct method:
Activate Gizmo3D, hold the Ctrl/Cmd modifier, and tap the desired target model to replace. ZBrush identifies the selected element for mask isolation by its polygroup. Most IMM brush components have unique polygroup colors, making them easy to isolate with Ctrl/Cmd selection.
Holding Ctrl/Cmd and tapping a point on the surface aligns Gizmo3D to the tapped polygon's surface. Since this affects orientation, expect Gizmo3D's alignment to change when performing these steps.
For step 6, there are multiple methods to modify Gizmo3D's orientation before replacing an IMM component. Adjust Gizmo3D's alignment using the following methods:
Snap Gizmo3D to the object's center – Hold the Alt/Option modifier to unlock Gizmo3D from the object, then tap the Go To Unmasked Center icon.
Refine Gizmo3D's orientation manually – Hold Alt/Option to unlock Gizmo3D, then drag the Move or Rotate controls to reposition Gizmo3D relative to the model before replacing components.
Snap Gizmo3D to a polygon's surface normal – Hold Alt/Option and tap a polygon to align Gizmo3D to its normal direction.
7. Select any IMM brush and choose a component from the IMM brush menu to replace it.
Gizmo3D must be active to replace a model successfully. The replacement model aligns with Gizmo3D based on the original orientation set when the brush was created. Orientation results may vary when using default ZBrush IMM brushes.
8. Clear the Mask.
9. Tap Apply To Similar model to repeat the replacement operation to all instances of the target model, based on the Apply To Similar settings.
Learn more about the Apply to Similar functions in the Repeat To Similar Parts section provided in this guide.