【Realflow】Domain 节点翻译

Domain - Grid
This parameter set is used to specify a Hybrido domain's properties.
这个参数设置用于指定一个 Hybrido 域的属性。


Cell size
The Hybrido domain can be seen as bounded space that is subdivided into cells. Since RealFlow's HyFLIP solver uses an adaptive grid, the given “Cell size” value represents the length of the smallest voxel and is also shown in the form of small boxes at the domain's viewport icon. The size of the other grid elements is determined by RealFlow automatically.

Hybrido 域可以看作是被细分为细胞的有界空间。由于 RealFlow 的 HyFLIP 规划求解使用自适应网格，给定的"单元格大小"值表示的最小像素长度，也显示在域的视区图标的小框的形式。其他网格元素的大小由 RealFlow 自动确定。

Small values increase the number of cells and create more detail, but also take longer to simulate. Higher values are often used for previews, distant fluids or very large scenes. The number of cells is also responsible for the number of particles, because each volume element contains a certain amount of particles.

小值增加细胞数量和创建更多的细节，但还需要更长时间模拟。较高的值通常用于预览、 遥远液或非常大的场景。细胞的数量也是负责粒子，数目的因为卷的每个元素包含一定数目的粒子。

The value given here is directly connected to the project's scene scale settings. With RealFlow's standard scale of 1.0, one square of the viewport's grid measures exactly 1.0 m x 1.0 m. With the parameter's default value of 0.3, the smallest volume element of the domain is 0.3 m x 0.3 x 0.3 m. A value of 0.01 represents a voxel size of 0.01 m x 0.01 m x 0.01 m – that is just 1 cm per side. With such a tiny voxel size, the number of particles can easily reach several millions – depending on the size of the emitter. "Cell size" is measured in metres[m].

这里给出的值直接连接到该项目的场景规模设置。随着 RealFlow 的标准规模的 1.0，一个正方形的视区的网格措施正好 1.0 m x 1.0 m。与该参数的默认值为 0.3，最小的体积元素是域的 0.3 米 × 0.3 × 0.3 米。值为 0.01 表示体素大小为 0.01 m x x 0.01 0.01 m m — — 即每边只是 1 厘米。与这种小素尺寸、 粒子数目可以动辄达几个上百万 — — 大小的发射器。"单元格大小"被衡量米 [m]。

When you work with “Cell size” and objects you also have to take the object's “Volume” panel into consideration. There you will find another “Cell size” value, but this time for the rasterization of the colliding/interacting object.

当您使用"单元格大小"和对象你还要考虑对象的"音量"面板。那里你会发现另一个"单元格大小"的值，但这一次的光栅化的碰撞进行交互的对象。

Creation mode
You can choose from three different modes. “Adaptive” provides a very good compromise between speed and memory usage and is suitable for most situations. To make use of the “Dense” and “Sparse” options you have to know a few things about them:

你可以选择从三种不同模式。"自适应"提供速度和内存使用情况很好的折衷，是适用于大多数情况。要使用的"密集"和"疏"的选项，你要知道他们的一些事情:

When a domain with grid cells is added, RealFlow allocates a certain amount of memory. There are two fundamental ways to store the grid. In a so-called dense grid, all volume elements are stored, regardless whether they contain information or not. In a sparse grid, the situation is different: in this case, the grid is again subdivided into blocks of cells and memory will only be allocated when at least one cell within such a block contains information. The following parameter, “Block granularity” is used to adjust the size of these blocks.

当添加了域的网格单元时，RealFlow 分配一定数量的内存。有两种基本方法来存储网格。在所谓的密网格中，所有卷元素都存储，无论是否或不包含的信息。在稀疏网格中，情况是不同的: 在这种情况下，网格再划分为块的细胞和时至少一个单元格，这样一个块内的包含的信息，只会分配内存。下面的参数，"块粒度"用来调整这些区块的大小。

@ threshold
This parameter is exclusively connected to the “Adaptive” simulation mode. In a dense grid, all voxels are mapped inside the memory throughout the entire simulation. This results in a faster simulation and it is also more GPU-friendly. If the grid is very sparse, the amount of used memory can be reduced and you can simulate with higher resolutions (= smaller “Cell length”). 

此参数仅连接到"自适应"模拟模式。在密集的网格中，所有体素内整个的模拟内存映射。这将导致更快的仿真，它也是更多的 GPU 友好。如果网格是很稀疏，可以减少使用的内存，您可以模拟与更高的分辨率 (= 较小的"细胞长度")。

The parameter's value ranges between 0.0 and 1.0 and tells the solver how dense or sparse the grid will finally be. With 0.0 you have a perfectly sparse grid, while values around 1.0 are used for a completely dense domain. The entered number describes the ratio between cells with and without particles. This value is dimensionless and ranges between 0.0 and 1.0.

参数的值范围介于 0.0 和 1.0 之间，告诉规划求解如何密或稀疏网格将最后是。你有 0.0 完全稀疏网格，同时约为 1.0 用于完全致密的域的值。输入的数字描述细胞和无颗粒之间的比率。此值是无量纲的范围介于 0.0 和 1.0 之间。

@ block granularity
As explained above, a sparse grid is subdivided into blocks of cells to reduce the amount of memory for simulation. The size of these blocks can be adjusted with this parameter and a simple formula:

如上所述，稀疏网格划分为块的牢房，以减少内存的模拟量。这些块的大小可以调整此参数与一个简单的公式:

Total number of cells per block = @ block granularity 3

With the default value of 8, the total number of voxels per block is 83 = 512. The less voxels per block you have, the more memory-efficient the simulation will finally be, but with a side-effect: it will be less efficient in terms of computation and the simulation becomes slower. This value accepts integers and is dimensionless.

默认值为 8，每个块体素的总数是 83 = 512。每个块可以记忆效率越高仿真最后会但副作用更少素: 这将是的计算效率更低，模拟变慢。此值接受整数，并且是无量纲的。
 

Domain - Fluid Dynamics


Here you will find parameters to configure the fluid's physical properties.
在这里您将找到参数配置流体的物理属性。

Viscosity
Here you can enter the desired value to create different substances. You can find detailed information about this feature here; the table under "HyFLIP - Viscosity Values" provides several viscosity values for various fluids.
在这里您可以输入所需的值来创建不同的物质。你可以找到有关在这里; 此功能的详细的信息"HyFLIP-粘度值"下的表提供各种流体粘度的几个值。

Density
If you want to simulate highly viscous substances like chocolate or honey you can also enter the fluid's appropriate density value to get a complete material definition. Please bear in mind that it is currently not possible in Hybrido to simulate fluids with different “Density” values, for example oil and water. In most cases, this parameter can be left untouched.

如果你想要模拟高粘性的物质，如巧克力或亲爱的你也可以输入要获取完整的材料定义的流体的适当密度值。请牢记一点，它是目前不可能在 Hybrido 来模拟流体在不同的"密度"值，例如石油和水。在大多数情况下，此参数可以保持不变。

Conserve volume
A common problem with FLIP solvers is a loss of volume, caused by large time steps, which are used to decrease simulation time. One side effect of these large time steps are precision errors in the solver's advection step. Another issue can be observed in combination with fast moving objects: in this case, such an object is not able to displace the fluid, because it simply goes through the fluid without interaction and literally “eats up” the fluid's volume.

翻转解决常见的问题是体积的引起的大时间步长，用来减少仿真时间损失。这些大时间步长的一个副作用是在规划求解的平流步精度误差。另一个问题可以在快速移动的物体结合观察到: 在这种情况下，这种对象是不能够取代液，因为它只是穿过无交互作用的流体，从字面上"吃掉"的流体体积。

With “Conserve Volume” set to “Yes”, the solver will try to conserve the volume. Please bear in mind that this method has its limit and when the loss of volume is considerable (approx. 50% or more) then it is very difficult to recover the original volume. On the other hand, you might notice an increase of volume in some situations. As a rule of thumb, we can say that “Conserve Volume” works best when the loss of volume is not higher than 10-20% per second. In cases where the loss is higher it is likely that you will see artefacts. This problem can be addressed with a more restricted time step (= higher “MIN substeps” value of the “Hybrido Main Solver”).

与"节约量"设置为"Yes"，规划求解会尽量以保存该卷。请牢记此方法有其极限和丢失卷时相当大 (约50%或更多) 那么就很难恢复原始卷。另一方面，你可能会注意到在某些情况下量的增长。作为一个经验法则，我们可以说"保护卷"适合当丢失卷不大于每秒 10-20%。在损失较高的情况下很可能你会看到的文物。这个问题可以解决更多的限制的时间步长

You can read more about the influence of time steps and the interaction between objects and fluids here.

你可以阅读更多关于时间步骤和对象与这里的流体之间的相互作用的影响。

Vorticity boost
To get a more turbulent fluid, it is possible to increase the particles' spin with this factor. Please try to avoid very high values (unless necessary), because they can completely distort the fluid. "Vorticity boost" is an implementation of the better-known "Vorticity Confinement" technique which can often be found in smoke simulation tools.This value accepts floats and is dimensionless. In many cases, values between 0.0 and 2.0 produce satisfying results. Please bear in mind that "Vorticity boost" is verysensitive.

若要获取更多湍流流体，是可能增加粒子的自旋与这一因素。请尽量避免很高的价值 (除非必要)，因为他们可以完全扭曲的流体。"涡度提升"是名气更大的"涡监禁"技术可以经常被发现在烟雾模拟工具的实现。此值接受花车和是无量纲的。在许多情况下，值 0.0 到 2.0 之间产生令人满意的结果。请牢记"涡度提升"是我国。

 Track lonely particles
Hybrido fluid particles can leave the main fluid body. These isolated particles can cause a huge deformation when they hit the grid fluid's surface. To avoid this unwanted behaviour, it is possible to tag the isolated particles as “lonely”. Then, the particles merge again with the remaining fluid, but do not cause any visible interaction. This is the default mode and uses the lifetime parameters below.

Hybrido 流体粒子可以离开流体主体。这些孤立的粒子可以引起巨大的变形，当他们击中网格流体表面。为了避免这种不必要的行为，就可以标记分离的颗粒作为"孤独"。然后，粒子与剩余的液体中，再一次合并，但不是会导致任何可见的交互。这是默认的模式，并使用寿命参数下面。

@ min lifetime/@ max lifetime
Both describe the isolated particles’ lifespan. When you use different values (“@ min lifetime” must be smaller than “@ max lifetime”), the actual lifespan lies somewhere between both values. This can help to achieve more randombehavior. The lifetime parameters accept floats given in seconds[s].

两个描述孤立的粒子的寿命。当您使用不同的值 ("@ min 一生"必须小于"@ 最大寿命")，实际使用寿命介于两个值之间。这可以帮助实现更多的 randombehavior。寿命参数接受花车给出了在几秒钟内 [s]。