Ask : Simulation

Owned by thomas (Unlicensed)
Last updated: 19 Jun, 2018
3 min read
There is no significant boost in simulation speed with enabled GPU support. Why?

Dyverso is optimized for multi-core and many-core CPUs, but some GPU cards do not have enough computational power to outperform a modern 8 core or 12 core processor.

Gaming cards like the GeForce GTX 10 series or comparable AMD boards are perfectly suited for Dyverso and perform very good. The typical speed boost is around 4x compared to CPU simulations.

For more information visit → "GPU-Acceleration" or "→ "Ask : GPU-Acceleration".

Particles are not influenced through daemons or other fluid containers. What's happening?

In many cases, the links are established automatically by RealFlow | Maya, but there are also occasions where you have to connect interacting nodes.

Take a look the "Scene" and "Linked Domains" fields of the nodes involved:

  • If "Scene" and/or "Linked Domains" are empty the node will not be affected by other scene elements.
  • Specify the interacting nodes and "Scene" object.
I have applied an object to the "Object" emitter, but there is no emission. What's wrong?

When the body's polygons are very small it might happen that you will not get any particle emission. To fix this, increase the "Fluid" container's "Resolution" to create more particles. You may need very high settings (> 100 or more).

I only have a few particles in the scene, but I need more. What can I do?

The number of particles depends on several factors:

  • Resolution. Every fluid, rigid, and elastic container has its own → "Resolution" parameter. Higher values create more particles.
  • Emission area. Particles are created within a certain area or volume define by the emitter. If this area is very small the amount of particles will low as well.
  • Emission speed. Many emitters have a "Speed" value to control the particles' initial velocity. With 0, the emission stops and the higher the "Speed" value, the more particles you will get.
  • Scale. When the global scene scale is very small the emission are will shrink accordingly.
How many particles are enough for a simulation?

This question cannot be answered globally, because the amount of particles strongly depends on the scene. A general rule is: the more, the better. More particles mean more detail, better splashes, and a believable fluid behaviour.

Several hundreds of thousands of particles are absolutely normal and can be simulated very fast with Dyverso's → GPU options. Even several millions of particles are not problematic and often required for mid-scale scenes.

Is it possible to influence Bifrost through RealFlow | Maya and vice versa?

No, both technologies are completely different and cannot be connected.

I see exploding particles when they interact with objects, for example when I try to fill a glass. What's going on?

RealFlow | Maya works with adaptive substeps by default and this means that RealFlow determines the actual number of substeps.

When particles settle, the number of substeps decreases, and this means less precision. As a consequence physical effects inside the fluid start to accumulate until a "pop" occurs. After the explosion the particles settle again, and RealFlow increases the number of substeps - the beginning of a new cycle. To avoid this effect increase the number of → "Min Substeps" and/or → "Min Iterations".

Some deamons don't have a falloff function. Why?

Yes, the "Crown", "Drag", "Magic", and "Surface Tension" do not offer a falloff function. The reason is that the force fields of these daemons depend on hte particles' positions and velocities - properties which change over time. In such a case it is not possible to calculate an adequate falloff and the falloff's borders would change with every simulation step.