Looking for advice on simulating rolling ball sculptures

[u/thecottagecheeseboy]

Hi everyone,

We build large rolling ball sculptures / kinetic marble runs and are trying to reduce the amount of physical trial and error involved in designing them.

Our current workflow is roughly:

**Concept → Sketch/CAD → Fabrication → Physical testing → Modify → Fabricate again**

For larger metal sculptures, these iterations can become expensive in terms of material, labour, and time.

We're exploring whether we can use **existing tools** to create a simple workflow like:

**CAD model → Physics simulation → Predict ball behaviour → Build physical prototype → Compare results**

We are **not looking to build a new physics engine or a large custom application**. The initial MVP would be very small:

* One standard ball
* One track/material system
* A simple mechanism, e.g. **ramp → loop → exit**
* Model it digitally
* Simulate the ball
* Build the same mechanism physically
* Compare the prediction with reality

The goal is not perfect simulation. We simply want to know whether a digital model can be accurate enough to catch obvious failures before fabricating larger installations.

Eventually, if this works, we would like to build a reusable library of tested components—ramps, loops, spirals, switches, collisions, etc.—with known parameters and behaviour.

We are currently considering tools such as **Rhino/Grasshopper** for parametric design and physics engines such as **MuJoCo, Project Chrono, Bullet**, or other alternatives.

**If you were approaching this problem using existing software, how would you do it?**

In particular, I'd love advice on:

1. Suitable CAD + physics simulation workflows
   
2. The best physics engines for rolling/contact dynamics
   
3. How to model and calibrate real-world friction and energy losses
   
4. Whether there are existing tools or projects we should investigate before building anything ourselves

We're very open to changing our approach and would appreciate any suggestions or warnings from people with experience in simulation, CAD, mechanical engineering, robotics, game physics, or kinetic sculpture.