PreonLab 3.3 represents the final 3.x release and we are very excited to share it with you. Here is a selection of the most notable new features and improvements:

• Non-Newtonian fluids: For the first time, the Preon Solver supports the simulation of non-Newtonian fluids.
• Improved car suspension model: The improved car suspension model now simulates vehicle suspension due to fluid interaction more accurately and supports user-defined spring constants.
• Improved efficiency: PreonLab 3.3 includes an optimized geometry handling that improves performance, cuts down loading times and reduces memory consumption
• “Experimental” mode: The experimental mode exposes selected features currently in development to all users who wish to try them out

We will publish videos showcasing some of the new features in the coming weeks. Make sure to follow us on LinkedIn so that you don’t miss them!

Non-Newtonian fluids

The implicit viscosity solver introduced in PreonLab 3.2 greatly increased the capability of the Preon Solver in terms of viscosity modeling. However, the solver was still strictly limited to Newtonian fluids. PreonLab 3.3 removes this limitation by introducing the power law viscosity model. The power law model can be used to simulate a wide range of both Newtonian and non-Newtonian fluids like polymer solutions and suspensions. While it can be used with the explicit viscosity solver, it also supports semi-implicit integration and therefore allows for the fast simulation of highly viscous flows. PreonLab 3.3 also improves the existing model for Newtonian fluids by introducing decoupled parameters for bulk and shear viscosity.

Improved car suspension model

Modeling car suspension due to fluid pressure is an important component of every car wading simulation. For PreonLab 3.3, we improved the car suspension model according to your feedback and also implemented some changes that simplify the overall workflow when setting up a wading simulation. Firstly, the suspension model now supports user-defined spring constants and damper coefficients. Secondly, we created a more flexible interface to specify the weight distribution and the resulting center of mass. Both changes allow for a more accurate simulation of car suspension in a range of different scenarios.
We also updated our tutorial and the auxiliary python script used to set up the car kinematics. The new tutorial and the script make it simpler and more intuitive to move from our generic example to your specific wading application.

Improved efficiency

The ability to handle any geometry without manual pre-processing has always been one of the key strengths of PreonLab. However, in some cases the purely particle-based approach used by PreonLab requires a significant amount of solid particles in order to represent geometries. Consider a single rain drop falling down on a huge geometry – in the past, PreonLab would sample the entire geometry with particles in order to compute interactions between the rain drop and the geometry. To reduce memory consumption and improve performance, PreonLab 3.3 introduces a new feature that we call dynamic sampling. In a nutshell, dynamic sampling will generate solid particles only where they are required and when they are required. The two images below show an example in which only a fraction of the geometry surface is sampled without compromising on simulation quality. Additionally, we also optimized the scheduling of solid particles to CPU cores, which can improve performance regardless of whether dynamic sampling is used or not. Combined, these changes can add up to significant performance gains in many setups, including raining simulations, rigid body simulations and MPI simulations with moving geometries. In PreonLab 3.3, dynamic sampling must be activated explicitly in the property editor. It will become the default in PreonLab 4.0 later this year.

New “experimental” mode

At FIFTY2, we try to fully embrace agile software development – PreonLab is undergoing constant evolution to meet your high standards and expectations. This process works best if we get feedback from our users as fast as possible, which is why we release multiple updates with new features each year. However, balancing the desire for early feedback and providing a stable and reliable software is sometimes challenging. We therefore decided to introduce a new “experimental” mode, that exposes selected upcoming features to users who want to try them out. These are features that we consider usable, but that are not yet fully evaluated and optimized. As part of this new mode, PreonLab 3.3 includes the new snow solver that is scheduled for PreonLab 4.0.