FreeCAD's usual geometry tools do not naturally handle signed distance fields, and that is the gap this project addresses. The maker has built a workbench that brings SDF shapes into FreeCAD, using analytic signed distance fields for base geometry while rendering lower resolution voxel based fields to keep things fast. For anyone curious about SDF modeling, having it live inside a familiar CAD environment seems like a very welcome development.
The way it is put together stands out. A 3D grid is stored on the graphics card, and every cell in that grid holds the distance to the nearest surface. A full-screen square, or billboard, sits in the Coin3D scene, and for each pixel a ray is sent through the grid to find a surface hit. The billboard carries a callback so drawing happens during each frame, plus real 3D depth so the shapes sit correctly against the rest of the scene. Shading uses a matcap, ambient occlusion, and selection highlights.
The demonstrated workflow is a nice sequence. A spherical SDF primitive is created with a radius near 26.15 mm, then a noise tool is applied in 'Waves' type and 'Additive' mode with an amplitude of 5.00 and a wavelength of 11.00 mm, with the 3D gizmo rotated about 51.3 degrees along the Y axis. A box primitive spanning the sphere surface, sized 16.04 by 15.22 by over 50 mm, is toggled to 'Make Subtractive' and run through the Boolean Subtract tool. The transform gizmo then scales and repositions the box deeper through the sphere, leaving a deep rectangular trench cut cleanly through the rippled result.
Notably, the internal FreeCAD renderer is not replaced; SDF shapes are drawn alongside normal FreeCAD geometry. Converting brep to sdf is still in progress, and the stated goal is generating 3D cam toolpaths from signed distance fields.