In Modeler, the retopology tools are based on Houdini’s standard TopoBuild tool, but with a key difference in how the modes are activated. In Houdini, TopoBuild modes are triggered using the Shift+1...6 hotkeys. In Modeler, all retopology modes are conveniently grouped in the Topo radial menu. This allows you to activate any mode directly from the menu without needing to first activate TopoBuild and then select a mode. If the TopoBuild node hasn’t been created yet, activating one of the Build, Slide, Split, Brush, or Smooth modes from the menu will automatically create the node.

How to Retopologize in Modeler:

• Open the Topo radial menu using Alt+W and check the Topo checkbox.
  • The tool will prompt you to select a high-poly object. After selecting, it will temporarily hide the object and ask you to choose the object in which you want to continue retopology.
  • If you need to create a new object for retopology, simply press Enter without selecting anything.
  • The viewport settings will adjust to better display polygons over the high-poly model.
• Use the tools from the Topo menu: Build, Split, Slide, Brush, Smooth, and Draw Patch.
• You can also use other modeling tools, and to project the result onto the high-poly model, use the Project tool from the Topo menu.
• To finish retopology, activate the Topo tool again. This will reset the viewport settings, display the high-poly object, and the tools will no longer consider the retopology mode.

Tools in the Topo Menu:

• Topo — Activates retopology mode.
• Project — Projects all current geometry onto the high-poly object.
• Build, Slide, Split, Brush, Smooth — Standard retopology tools using the TopoBuild node.
• Draw Patch — A tool for creating patches, allowing you to intuitively wrap the high-poly model with polygons, saving time and eliminating the need to manually create multiple polygons.

Draw Patch

The Draw Patch tool allows you to create patches by drawing contours. Automatic snapping of the cursor during drawing makes it easy to connect patches together. By hovering the cursor over the drawn curve and using the mouse wheel or pressing keys 1 or 2, you can control the number of subdivisions on the patch's side.