Rough Surface Generator

I made this OpenSCAD generator because I wanted an easy way to create rough, low-poly stone surfaces without having to model every detail by hand. I used ChatGPT to help me.

The generator creates a solid base with a randomly faceted top surface. It works well for things like terrain pieces, bases, walls, ruins, decorative parts, or anywhere you want a simple carved-stone / rock-like texture.

After importing to CAD program, you can use it as a part of different models.

There are two versions included. The Regular Mesh version uses a cleaner, more structured mesh, while the Randomized Mesh version also shifts the points sideways and randomizes the triangulation, so the result looks less like a grid and more natural. I personally prefer the randomized version for most stone surfaces.

You can choose between three base shapes:

• Rectangle / square

• Circle

• Ellipse / oval

The main parameters are easy to change directly at the top of the OpenSCAD file. You can adjust the overall size, mesh density, surface roughness, base thickness, random seed, and in the randomized version also the amount of XY point variation.

Changing the seed gives you a completely different surface while keeping the same dimensions.

For example, if you want larger and more visible stone facets, use fewer divisions and increase the roughness a little. If you want a finer surface, increase the number of divisions and reduce the roughness.

The model is generated as one closed polyhedron, so it is much lighter and easier to work with than a version made from hundreds of hull() operations.

Exporting

For 3D printing, simply render the model in OpenSCAD with F6 and export it as STL.

If you need a STEP file, the easiest workflow is:

OpenSCAD → export STL → open the STL in FreeCAD → convert the mesh to a shape/solid → export as STEP.

Keep in mind that the stone surface is intentionally faceted, so the STEP file will still contain the low-poly stone geometry rather than becoming a smooth CAD surface.

I included both generator versions so you can experiment and choose the style that works best for your model.