gn-sdf-remesh

Geometry Nodes SDF Remesh

A runnable example that remeshes an input mesh through an OpenVDB SDF grid using the build_remesh_via_sdf pattern from the geometry-nodes-python skill: GeometryNodeMeshToSDFGrid → GeometryNodeGridToMesh at the SDF zero-level, attached as a NODES modifier and evaluated via the depsgraph.

Which fix it witnesses: an SDF grid is meshed with Grid to Mesh, not Volume to Mesh (the Mesh to SDF Grid output is a grid socket; Volume to Mesh takes a volume-geometry socket, so wiring the grid there is an invalid link that yields no geometry). Grid to Mesh has the matching grid input.

Materials gotcha: geometry generated by Geometry Nodes carries no material, so the input mesh's material is dropped on remesh (the result renders with the default white). Re-apply it inside the tree with a Set Material node (GeometryNodeSetMaterial) on the remeshed output — this example does that and asserts the material survives onto the evaluated mesh.

Run

# Cheap correctness check only (no render) — the CI smoke check:
blender --background --python gn_sdf_remesh.py --

# Also render the remeshed result (EEVEE on a GPU host; --engine cycles on GPU-less hosts):
blender --background --python gn_sdf_remesh.py -- --output remesh.png
blender --background --python gn_sdf_remesh.py -- --output remesh.png --engine cycles

By default it runs only the frame-independent correctness check: the depsgraph-evaluated vertex count must be > 0 AND differ from the base mesh (the remesh produced geometry). It exits non-zero on failure — the same check the blender-smoke workflow runs on Blender 4.5 LTS and 5.1.