Export STEP file?

Hey there I have a client who wants a 10M triangle count mesh of a seamless pebble displacement model exported out as a STEP file.

Has anyone had any success exporting this file format from Blender or through any other process?

Thanks in advance.

The problem is that in blender you create a mesh with vertices, edges and faces with a finite resolution and STEP is used to store parametric surfaces (so called NURBs) with therefore almost infinite precision. These are two fundamentaly different things.

But I found a thread about a free workflow to achieve a relative good conversion: From Blender Subdivision To N.U.R.B.S. (IGES) for free

Direct conversion of mesh to NURBS generates a NURBS surface for every triangle.
CAD systems are limited by the number of surfaces, at best you might get a mesh with 20,000 triangles converted to NURBS via a direct conversion that will successfully read in to a CAD application.
One NURBS surface per triangle is needed because an interpolated surface that some reverse engineering software can generate will smooth out all the “noise”, which exactly what you want to keep.

If the desired output is for CNC that will use a rotating cutting tool (ie. milling machine, router) the best option for your client is to use a system that can import a mesh.
Many CNC machines used in signage will accept meshes for cutting in soft materials like wood and foam.

Alternatively, some laser machining systems can now use greyscale images instead of 3D files