GPU accelerated cloth and rope simulations

Back in April of this year Maxon updated Cinema 4D with a new selection of tools to improve the simulation of rope and cloth. The main selling point over competing software such as SideFX's Vellum, is an incredibly fast GPU-based dynamics system. This promises significantly faster calculation resulting in a smoother user experience.

The company have continued to improve the feature throughout the year, and I've been keen to see how it stands up.

Soft, folded ribbons, simulated in Cinema 4D.

Cinema 4D's cloth system is highly multi-threaded, and it is easy to see and feel that in use. Even very basic tasks such as a cloth sliding across an object are visibly multiple times faster than an equivalent setup in Vellum. This makes content creation and artistic experimentation a genuinely fun process. Iterating on concepts or simply trying out a new idea becomes effortless.

One area that really stands out is viewport interaction. The ability to manipulate objects directly while a simulation is running seems crazy to me. Cinema 4D allows input actions to be recorded and replayed, making even the most random of manual gestures easy to repeat.

Arguably Vellum still offers more finite and accurate control over a simulation, and it is a more mature product, but the speed of Cinema 4D here really sets it apart. Throw any number of ropes into a complex animation and the results will be stable, predicable, and perhaps even more importantly, art directable.

Cinema 4D rope simulation with multiple wires intertwined and entangled.

I have only begun to scratch the surface so far, there is so much more to look into - including cloth tearing, ballooning and interaction with soft body meshes.

Rendering performance made a huge leap forward when it moved from CPU to the GPU and now we're seeing similar things in the area of simulation. I continue to be excited by the progress of EmberGen, the GPU based real-time fluid simulation tool, while plugin developers Insydium recently migrated their particle simulation framework Nexus on to the GPU.

This kind of technological innovation enables artists to tackle projects that previously might have required additional hardware or considerably more patience.

A vibrant red and gold cloth material, simulated using Cinema 4D.

Credit to Mohamed Daoui for the gorgeous dress fabric material that's doing most of the heavy lifting here. Notably, this simple cloth took seconds to create using a single object and a rotational force effect. Five minutes setup and, boom, out pops a plausible cloth model. There is so much creative potential here.