---
title: "Modify Topology"
url: "https://help.maxon.net/zbp/en-us/Content/html/4_palettes_tool-3-geometry-modify-topology.html"
section_path: "Palettes > Tool Palette > Geometry > Modify Topology"
description: "Features dedicated to modifying geometry for the selected object."
---

# Modify Topology

Features dedicated to modifying geometry for the selected object.

### ![Image: 2024-4-tool-palette-geometry-modify-topology.png](https://help.maxon.net/zbp/en-us/Content/Resources/Images/2024-4-tool-palette-geometry-modify-topology.png)

Geometry > Modify Topology > Mirror And Weld

### Mirror And Weld

Mirrors and welds the selected subtools topology across the selected axes assigned in the XYZ menu.

> **Note:** Geometry welds along the selected axes to create a perfect edge loop around the model.

> **Tip:** If a model's symmetry breaks, resulting in asymmetrical brush strokes, this is a solution correcting the asymmetry.

#### XYZ

Selects the desired axes to mirror and weld a model's topology.

> **Important:** **Mirror And Weld** is directly affected by **Local Symmetry**.
>
> **Local Symmetry** off tells ZBrush to use the world origin (floor grid center) as the symmetry source for the mirror and weld effect.
>
> **Local Symmetry** on tells ZBrush to use the model's center origin as the symmetry source for the mirror and weld effect.
>
> **Local Symmetry** + Dynamic mode tells ZBrush to use the Gizmo3D position relative to the model as the source for the mirror and weld effect.

> **Tip:** Local symmetry is commonly needed when using **Mirror And Weld** to make a model symmetrical when it's not sitting at the world origin.\
> After applying **Mirror And Weld**, keeping **Local Symmetry** active in the desired axes ensures that sculpting and painting symmetrically off world center remains functional.
>
> Where **Local Symmetry** Dynamic mode is active, symmetry dependents on Gizmo3D orientation relative to the model. Realign Gizmo3D to the model to realign symmetry.

### Delete by Symmetry

All geometry on the opposite side of the selected axes is deleted.

### ![Image: 2024-4-tool-palette-geometry-modify-topology-delete-by-symmetry.PNG](https://help.maxon.net/zbp/en-us/Content/Resources/Images/2024-4-tool-palette-geometry-modify-topology-delete-by-symmetry.PNG)

### Delete Hidden

Any hidden geometry on the currently selected subtool is deleted.

> **Note:** Geometry can be hidden by using the selection brushes and tools. Learn more in this guide's [Selection Brush Essentials](https://help.maxon.net/zbp/en-us/Content/html/5_sculpting-and-painting_selection-brush-essentials.html.md) section.

### Weld Points

All unmerged points from the selected Subtool are merged.

> **Important:** Unwelded vertex points results in surface holes that are generally undesirable and unsuitable for sculpting and painting.

> **Tip:** Unwelded points commonly occur either when 3D models are not natively exported with weld vertex options activated.

#### WeldDist

Defines the distance between vertex points to weld. Lower values welds points that are very close together, and higher values weld points at greater distances.

### Close Holes

Closes any holes in your geometry.

> **Important:** This feature does not work when geometry is hidden for the currently selected subtool. Press Ctrl/Cmd and tap on the canvas to **Show All** hidden geometry.

> **Tip:** If you have hidden geometry blocking your ability to close a hole, try using the **Modify Topology > Delete Hidden** option to remove it completely. Then use **Modify Topology > Close Holes** to seal the hole for further sculpting and modeling.