Hi all,
Anyone working with photogrammetry city meshes has probably hit this: the textures look great, but up close the geometry doesn’t hold up. Walls ripple, roof facets are full of triangle noise, ridges saw-tooth and building corners come out rounded. It’s fine from a distance, but it breaks down for close-up renders, lighting studies, measurement, or anything that goes into a CAD/BIM workflow.
The usual fixes all cost you something:
- Remeshing/retopo loses the UV mapping, so you have to re-bake the texture atlas.
- Laplacian-style smoothing softens everything, including the edges you wanted to keep.
- Manual cleanup doesn’t scale beyond a couple of buildings.
I built a Blender add-on called Planer to handle this for the digital twin work I do. It takes a different approach:
- Detects planar regions in the mesh (walls, roof facets).
- Classifies each vertex by how many regions it belongs to:
- One plane: it’s projected onto that plane.
- Two planes: it’s snapped onto their intersection line, so ridges and eaves come out mathematically straight.
- Three planes: it’s snapped to the three-plane intersection point, so corners come out sharp.
- Moves vertices only. Topology connectivity, UVs and materials are left alone, so the photo texture stays correctly mapped with no re-bake.
Every run also reports how far the result sits from the source surface, so you can check that it stayed faithful:
Refined: 195184->195184 faces, 812 planes, 96431 verts snapped
(4210 edge, 388 corner) | deviation mean 0.072m p95 0.275m max 0.864m
[before/after image, rendered untextured so the geometry change is visible]
Practical notes:
- A city block of about 195k faces takes around 4 minutes on a desktop CPU.
- The output is always a new object. The source mesh is never modified.
- It doesn’t fill holes or make meshes watertight. Open photogrammetry shells stay open.
- It needs Blender 4.2 or newer.
I’d like to hear how others here handle geometry clean-up on reality-mesh data before it goes into visualization or analysis pipelines. And if you have a problem mesh, I’m happy to run it through and share the result.
Product :- Search for PLANER – Photogrammetry mesh refiner