Join Andy Needham for an in-depth discussion in this video Making fluids, part of X-Particles 3 for Cinema 4D Essential Training.
- Introduced in X-Particles Version 3, the Flips Over builds on the SPH fluids from X-Particles 2.5. Let's take a look at how we go about creating Fluid Simulation. First, we'll need a system and an emitter. I'm going to change this to be a sphere. And I'm going to make some changes to the visual. So, we'll have some blue squares. Something like so. Just reduce this down a bit.
To make fluid sims, we need somewhere to hold them. For this we use the Domain object. In Dynamics, we can add the FLIP Domain. And this is what we see. We need to make sure the emitter, or Emission Object, is inside the domain to have any effect. And, currently as is, so that's fine. If we press "play," we can see the fluids being generated.
But, it's not really what we're after. Let's add some Gravity so the particles can fall down and fill the domain. Just add a Gravity modifier here and we'll give ourselves a bit more time. What's nice is that you can immediately see the effect that we're having. Now we're getting fluid falling down and filling the container.
Let's discuss the main settings. Currently, we've got it set to "Liquid," which is exactly what we want. We're not concerned with any of these modes at this point. The "Weak Spring" is a way of distributing the particles and in the third sims it can keep the liquid volume. We have a "Strength" slider to control that. It does add to the calculation, but we can leave it checked for now. Vorticity adds more turbulent motion to the sim. It's great for fire and smoke. This setting is linked to the grid resolution.
More on that in a moment. You can add a vorticity modifier or a turbulent modifier to increase the effect. Viscosity of the fluid is how thick or sticky it is. Increasing this value will result in the particles sticking together, it will give them like an internal friction producing a gooey, syrupy-like quality. I mention the Grid Resolution and you can see the grid here in the view port. It's that yellow box. These represent the Voxel size and the lower the Voxel size, the more accurate and detailed the sim will be.
But it will be slower to calculate, of course. It's all relative to the bounds we give the domain. If we reduce the bounds, you can see the memory needed, this figure here, that's going to change. If I just reduce this down, you can see that's changed. If we reduce the Voxel size, you can see this jumped right up. This is because we have more Voxels and more detail so more memory is needed. See that the grid has got more concentrated here as well.
With more Voxels, you'll need more particles. With fluid sims, you're going to need a lot of particles, especially if you use the Skinner. With a lot of particles, the Skinner won't flicker as much. Let's increase the number by quite a lot. We'll do this in the Emitter. We're going to change the display setting to "Dots" there in the View Port. Let's rewind and play through that. There we are.
Having the capability to create these kinds of effects, inside C4D by via X-Particles is a real bonus. I think it fits into the C4D philosophy of making complex tasks approachable. In just a few steps, we've built a fluid sim and we didn't even have to go into all the settings to get a decent-looking result. We're getting pretty slow playback and it is impossible to see how this sim looks in real time. In the next movie, we'll discuss an important workflow technique when working with simulations and that is caching.
- Working with the Emitter tabs
- Adjusting particles with modifiers
- Creating visible particles
- Using sprites
- Colliding, freezing, and lighting particles
- Caching in X-Particles
- Applying constraints
- Adjusting materials settings
- Sculpting particles
- Saving and loading presets