栅格散度

栅格散度 节点计算存储于体素栅格中的矢量场的 散度。散度衡量场在每个点处的 “扩散” 或 “收敛” 程度，代表进入或离开体素的净流量。

A positive divergence value indicates that the field is expanding outward from that voxel (acting as a source), while a negative value indicates that the field is converging inward (acting as a sink). A divergence near zero means the field is locally balanced, with equal flow in and out.

该运算常用于流体与烟雾模拟流程中，其功能包括强制实现不可压缩性条件，或对速度栅格等矢量场的流动行为进行可视化呈现。

从数学角度而言，对于三维矢量场 \(\mathbf{F} = (F_x, F_y, F_z)\)，其散度定义为：

\[\nabla \cdot \mathbf{F} = \frac{\partial F_x}{\partial x} + \frac{\partial F_y}{\partial y} + \frac{\partial F_z}{\partial z}\]

输入

栅格

待计算散度的输入矢量栅格。该栅格必须存储三维矢量值，例如速度场或方向场。

输出

散度

表示输入场散度的浮点栅格。

Positive values correspond to regions where vectors spread apart (sources), while negative values represent regions where vectors converge (sinks).