Draw Xray
Addon for Blender 4.2+, that will show retopology overlay on top of your mesh. The paid version comes with custom snap engine and retopo stroke tool.
Free Version (add-on):
Video guide from Jayanam- showing the retopo Xray overlay (feature in both free and $ version)
Pros compared to build-in Blender retopo overlay:
This tool allows for clearer visualization of how your retopo mesh interacts with your high-poly model. You can easily identify which areas of the retopo mesh protrude beyond the high-poly surface and which areas lie beneath it (unlike built-in retopo overlay, which obscure this information)
customizable: faces overlay color, opacity,
supports drawing in: Sculpt, Edit, Paint, Object modes
option draw with-or without modifiers applied
Cons:
slower - it is coded in python, so it wont be as fast as native C++ code.
How to use:
Install DrawXray like any other Blender add-on - see Blender docs
In 3D View Top Bar > Viewport Overlays > 'Enable Xray' - if you go to mesh edit mode, you will se new overlay rendered on top of your mesh
Xray Overlay can be enabled in following modes: Edit, Sculpt, Paint, Object (Shift+Click to select multiple modes).
Paid version has Snapping section, where you can set snap target (All scene objects, single target or collection)
Paid version (extension)
comes with custom snapping engine and retopo tool:
Xray snap engine takes into account mesh curvature: sink lowpoly mesh into valleys, push outside on peaks. See this YouTube video below for details
Xray will negate mesh shrinking effect caused by subdivision modifier (see same video above),
Quad stroke - draw and extrude single edge strip (new in 4.0)
Strip Wrap around joints feature (new in 4.1)
Strip Stroke - draw and extrude multiple edges at once (new in 4.2)
paid version comes with built-in auto-updater (new in 4.0)
Video above focuses mostly on retopo Quad tools. At the very end I show demo retopology of character head.
Second video where I show improved snapping algorithm for: concave vs convex mesh parts, and subdivided vs non-subdivided mesh.
Studio vs Standard license: if you are company with above 180k $ income, please purchase Studio version. Both licenses (Studio and Standard) can be used commercially
Note: I included fixed version of F2 add-on (mesh_f2_xray.py) - which wont crash when using F2 together with DrawXray. To use patched F2 addon: disable the build-in F2 version and replace it with fixed version (it is named 'F2 Xray Fix'). For your information, I provided patch to blender devs, with the fix, but it got ignored...
Updates History
Update 2.3 Blender 2.8 only (23.08.2019)
fixed crashes on scripts reload, and other bugs.
by default per object snapping is now set to 'Global' . Saves few clicks: when you enable global snapping, all objects will use now global target. You can still change it per object in: 'Object Viewport' panel to: Disabled or Local (different snap target for each object)
Update 2.7 Blender 2.8 and 2.9 (19.11.2020)
addon draws more uniform edges now
more snapping options (based on shrink wrap modifier)
Simplified UI (there is no longer separate panel in object properties)
Update 2.8 for Blender 2.93 and 3.0 (01.12.2021)
Added compatibility with Blender 3.0
Update 2.9 for Blender 2.93 and 3.x (12.09.2022)
Added compatibility with Blender 3.3
remade snapping - only selected vertices will snap (in past - whole mesh would be snapped to high-poly obj)
Update 3.0 for Blender 2.93 and 3.x (17.02.2023)
Code refactor. Hopefully it will fix some random issues people are experiencing
Update 3.1for Blender 2.93 and 3.x (1.04.2023)
added compatibility with blender 3.5
Update 3.3 for Blender 3.5 and up only! (1.04.2023)
moved whole open-gl drawing to new GPU module in blender 3.5
Update 3.4 for Blender 3.6 and up only! (8.08.2023)
option to draw in Edit mode and/or Sculpt Mode and/or Object Mode and/or Paint Mode
Xray will show now shapekeys on object correctly
Update ver 3.6 (for version with snapping (24.11.2023) :
improved snapping behavior on concave areas
nicer results when using subdivision modifier on your retopo mesh,
ability to snap to any object (not just mesh types)
new - snap to: selected object, collection of objects, all objects
ability to affect neighbors of selected geometry, for nicer retopo mesh interpolation
added new - projected snapping method
Update ver 3.8 (for version with snapping (2.3.2024):
Fixed 'Projected snapping' method when using Orthographic view
fixed not being able to snap in mesh edit mode, when Xray overlay Mode was set to Sculpt only display method,
other fixes and tweaks
Update 4.0.0 for Blender 4.2+ (version with snapping only - Released 9.10.2024)
Added Draw Quad Strips option,
addon converted to extension,
Update 4.1.0 for Blender 4.2+ (version with snapping only - Released 21.10.2024)
Added Wrap Limbs - Shift+W,
improved searching for adjacent snap edges,
Update 4.1.1 for Blender 4.2+ - Released 24.10.2024,
Added 'Screen Space' Wrap option,
improve generation of last quad face (support more cases),
smoother first quad generation (thanks to introduced warmup period - help in calculating smoother stroke tangent)
Update 4.2.0 for Blender 4.2+ - Released 12.1.2025 (for version with snapping)
You can resample drawn quads with MMB+Scroll,
you can extrude multiple edges now,
added '2d Matching' for screen space calculations and detection of valid face edges,
Wrap Strip - you can resample it now in both directions,
Shift+Q - is used now for smoothing selected geometry,
undo is broken into stroke welded/non-welded segments now,
Brush uses multiple samples to pick smoother normal from highpoly mesh,
Update 4.2.1 for Blender 4.2+ - Released 13.1.2025 (for version with snapping only)
Fix: prevent snapping on Undo/Redo,
Fix for extending wire edges in Wrap Strip tool,
Fix for finding closest edge not always working,
added button to manually reload snap cache,
Update 4.2.2 - for Blender 4.2+ - Released 23.3.2025,
Blender 4.4 compatibility fixes,