Simulating sand behavior realistically

Hi All,
I’ve been working to initiate a project. The goal is to create a free teaching tool for beginning trackers (as in tracking animals), one that can be used to illustrate sand and foot behavior during formation of a track. It takes experienced trackers years to build these internal mental models. Creating a learning tool has merit because 3D visualization can drastically shorten the learning time required for beginners.

Realistic behavior is a paramount consideration for this project. Though I’ve come to enjoy creating with Blender, I’m afraid I may have nudged Blender as far as it will go in this direction, ie. I think I’ve reached a cross roads where the need for realism exceeds what Blender can do.

One thing I’ve learned is a healthy respect for the limitations one finds when trying to model reality!

I hope I’m wrong, and am asking for advice.

Can anyone point me towards ways to realistically model sand behavior?

So far I’ve used rigid bodies, and the particle system (with Molecular addon), and gotten useful results with both. Rigid Body seems to produce the most realistic action, but it lacks one important quality of sand behavior…clumping.

Take damp sand in your hand and squeeze … you’ll see what I mean.

To illustrate some aspects of track formation clumping is an essential quality. I used the Molecular addon because it offers this quality. It works well, but as the author described, it is not meant for precise realism.

If I’m right, and Blender just can’t do this level of reality yet, can anyone point me towards open source software that might?

I’d attach a clip but .mp4 files aren’t allowed?

The clip demonstrates a bit of where I’m trying to go. It’s a canine claw leaving it’s track as the animal decides to turn left. It’s not polished by any means, but I was just trying to get the concept going.


not sure what your after, keep in mind that Blender is a animation movie tool, not some kind of ocrrect physicss simulator.
Ea, people fake things to get things looking as real.
If you want the real thing, then do the real thing, take sand and shoes / animal feet , and film it.

If its more for like introducing yourself and a cool animation, maybe go for weight painted bump maps.

This seems… ambitious. Almost all software for simulating this kind of thing for VFX (rather than scientific purposes) will have shortcuts to save on compute time whilst keeping a realistic looking result. Blender is certainly not up for the job you describe, closest VFX software I can think of that would get as close as possible (endlessly configurable, you could create a realistic-ish setup with a bit of work I’m sure) is Houdini, but it’s not free and its tricky to learn.

Other than that you might want to look to more scientific tools but you wont get particularly visually pleasing results.

Take a look at houdini sand simulation here:

That first link is close to the direction I’m trying to head.
Got a call into Houdini to discuss this with them, see if cheap version will do what I want.
Learning Blender wasn’t easy, got the gears now though.
Thanks again.