Retopoflow

by Orange Turbine

Retopoflow Mode

In previous versions, Retopoflow tools were only accessable in a special mode that was completely separated from the rest of Blender. Since Retopoflow 4, these tools have been integrated tightly into Edit Mode. However, switching to one of the Retopoflow tools does still enter you into a type of mode that is specifically set up for retopology.

Entering a Retopoflow tool will adjust Blender’s settings for:

While that is a big list, you should never have to think about any of those things and the tools should ‘just work’, which is why they are automatic.

Switching out of a Retopoflow tool will restore all of your previous settings. You can enable or disable any of these automatic behaviors in Retopoflow’s preferences.

Terminology

Source Object(s) : The original object(s) that you are re-creating. These meshes typically have a high polygon count with poor topology and edge flow (ex: result of Dyntopo in Sculpt Mode)
Retopology Object : The new object that stores the retopologized surface. This mesh typically has a low polygon count with good topology and edge flow.

You must have at least one source object to draw on for the Retopoflow tools to function.

Any mesh object that is visible and not the active retopolgoy object is considered a source object by default. This means that you can hide or move objects to different scenes to change which source objects will be retopologized.

Overlay

Retopoflow uses Blender’s native retopology overlay.

If you are seeing the retopology object poke too far through the source object, decrease the retopology offset distance. Choosing an appropriate distance is important not just for visual clarity but also for not accidentally grabbing or snapping to the wrong verts. This setting has been added to the tool settings header for convenience.

Snapping

You can be more specific about which objects are considered sources in the Snapping menu. There, you can set a specific object, specific collection, filter to only selected objects, or filter to objects marked as selectable in the outliner.

Retopoflow does not snap the same way as Blender, since Blender’s snapping is not great for retopology. In Blender, you cannot snap to a vertex of the low poly without also allowing snapping to all of the high poly vertices. In Retopoflow, that’s no issue! Retopoflow also helps by recalculating the normals when needed, merging verts by pixel distance so object scale isn’t an issue, allowing source filtering, and switching between screen space and world space snapping methods automatically.

But, if you would prefer to snap to the verts or other components of the high poly, you can do so in in the snapping menu. Enabling source vertex snapping switches Retopoflow to use Blender’s native snapping. Blender’s snapping does not allow for source filtering, so those options disappear when the native transform is being used.

There is a section in the Snapping panel called Source Feature Detection, which is currently experimental (feedback encouraged!). When you enable detection of any of the features, Retopoflow will process all the source objects and allow you to snap to whichever edges are included. This snapping works across tools whenever moving or creating geometry, and helps with retopologizing hard surface objects, especially those created in CAD programs. It is not available when using Blender’s native transform.

Selection

Selection in Retopoflow tools follows Blender’s selection paradigm as much as possible.

The main difference is when using the brush-based tools like Tweak and Relax. In those, selection cannot be done with LMB (left mouse button) because that action is already used to apply the brush. Instead, you can use other Blender hotkeys like Shift LMB to toggle select, B to box select, or Ctrl RMB drag to lasso select.

Also, since Ctrl LMB is already used for creating new geometry in the other tools, Blender’s Pick Shortest Path operator is not accessable with that hotkey. However, you can still use Shift Ctrl LMB to the same effect. The Fill Region option is disabled by default for Shift Ctrl LMB in Retopoflow to make it behave like Ctrl LMB.

Loop selection in Retopoflow in Blender 5.1+ will end at inner corners by default. You can disable this and the above shortest path tweak by turning off Selection Adjustments in the Tool Switching preferences.

The tools in Retopoflow can be used in any selection mode, but are generally more useful in some than others. For example, PolyPen expects to connect to edges and verts but not faces, so switching to PolyPen enables both edge and vert selection and disables face selection by default. All tools have a preferred selection mode that is set automatically when switching to the tool.

Tip: In Blender, you can always enable multiple selection modes by holding Shift while choosing them.

Blender’s default shortcut for loop selection is Alt Left Click or Double Click depending on your preferences. In Retopoflow, you can always use both!

A LMB Drag that is not near any geometry will perform a box, lasso, or paint selection based on whichever selection tool is active at the top of the toolbar. This fallback tool can also be changed using Blender’s Alt W hotkey. You can turn this selection fallback off in the Tweaking menu. It is only available when Mouse Auto Selection is on, which it is by default.

A LMB click away from geometry in any tool will clear the selection.

Common Settings

All settings for the Retopoflow tools can be found in the 3D View tool header, the sidebar in the Tool tab, or the Tool tab of the Properties Editor when the tool is active in the 3D View toolbar.

The insert tools share the same Tweaking settings for how big the selection hitbox is, whether vertices are auto-merged, and how big the auto-merge threshold is while using LMB Drag on geometry to tweak it. These settings are not the same as the Tweak Brush tool settings.

The non-brush tools have a Tweak Loops mode that replaces edge grab with a loop select and slide. It is off by default in all tools except Contours.

Brush tools have the same Brush settings, though they are not shared across the tools. That way, you can use a small Tweak brush with a large Relax brush if you prefer.

Brush tools share the same Masking settings, so masking seams for Tweak will also mask seams for Relax.

General Options

The far right side of the tool settings in any Retopoflow tool is the General Options dropdown. In it, you can:

Switching Tools

You can quickly switch between Retopoflow tools and access some of their common settings by using the Retopoflow pie menu. It is currently mapped to the hotkey W while a Retopoflow tool is active.

You can add a custom hotkey for any tool by right clicking and choosing Assign Shortcut.