为什么虚幻引擎有时会以不同的方式查看fga文件？

Question

我发现虚幻引擎有一些不一致之处，无法弄清楚它是如何工作的。我的设置是我试图在虚幻引擎中可视化预制的Fluid Grid ASCII（.fga）文件。在某些情况下，结果不是预期的结果，并且向量略有错误。让我举个例子：

使用这个简单的.fga文件：

2.0, 2.0, 2.0,
-1.0, -1.0, -1.0,
1.0, 1.0, 1.0,
1.0, 1.0, 1.0,
-1.0, 1.0, 1.0,
1.0, -1.0, 1.0,
-1.0, -1.0, 1.0,
1.0, 1.0, -1.0,
-1.0, 1.0, -1.0,
1.0, -1.0, -1.0,
-1.0, -1.0, -1.0

在Blender中（借助于this add-on（感谢Github用户isathar）），此字段具有向内指向原点的所有8个矢量。每个黄点代表相应向量的尾巴：

在虚幻引擎中，该字段看起来与预期的一样（抱歉，低质量的虚幻引擎未显示矢量的实际大小）：

x，y和z的正轴分别被着色为红色，绿色和蓝色。

但是，此字段稍大：

4.0000000,4.0000000,4.0000000,
-5.0000000,-5.0000000,-5.0000000,
5.0000000,5.0000000,5.0000000,
-0.0000000,0.0000000,5.0000000,
-0.0000000,5.0000000,0.0000000,
-0.0000000,0.0000000,-5.0000000,
-0.0000000,-5.0000000,0.0000000,
-0.0000000,0.0000000,5.0000000,
-0.0000000,5.0000000,0.0000000,
-0.0000000,0.0000000,-5.0000000,
-0.0000000,-5.0000000,0.0000000,
-0.0000000,0.0000000,5.0000000,
-0.0000000,5.0000000,0.0000000,
-0.0000000,0.0000000,-5.0000000,
-0.0000000,-5.0000000,0.0000000,
-0.0000000,0.0000000,5.0000000,
-0.0000000,5.0000000,0.0000000,
-0.0000000,0.0000000,-5.0000000,
-0.0000000,-5.0000000,0.0000000,
-0.0000000,0.0000000,5.0000000,
-0.0000000,5.0000000,0.0000000,
-0.0000000,0.0000000,-5.0000000,
-0.0000000,-5.0000000,0.0000000,
-0.0000000,0.0000000,5.0000000,
-0.0000000,5.0000000,0.0000000,
-0.0000000,0.0000000,-5.0000000,
-0.0000000,-5.0000000,0.0000000,
-0.0000000,0.0000000,5.0000000,
-0.0000000,5.0000000,0.0000000,
-0.0000000,0.0000000,-5.0000000,
-0.0000000,-5.0000000,0.0000000,
-0.0000000,0.0000000,5.0000000,
-0.0000000,5.0000000,0.0000000,
-0.0000000,0.0000000,-5.0000000,
-0.0000000,-5.0000000,0.0000000,
-0.0000000,0.0000000,5.0000000,
-0.0000000,5.0000000,0.0000000,
-0.0000000,0.0000000,-5.0000000,
-0.0000000,-5.0000000,0.0000000,
-0.0000000,0.0000000,5.0000000,
-0.0000000,5.0000000,0.0000000,
-0.0000000,0.0000000,-5.0000000,
-0.0000000,-5.0000000,0.0000000,
-0.0000000,0.0000000,5.0000000,
-0.0000000,5.0000000,0.0000000,
-0.0000000,0.0000000,-5.0000000,
-0.0000000,-5.0000000,0.0000000,
-0.0000000,0.0000000,5.0000000,
-0.0000000,5.0000000,0.0000000,
-0.0000000,0.0000000,-5.0000000,
-0.0000000,-5.0000000,0.0000000,
-0.0000000,0.0000000,5.0000000,
-0.0000000,5.0000000,0.0000000,
-0.0000000,0.0000000,-5.0000000,
-0.0000000,-5.0000000,0.0000000,
-0.0000000,0.0000000,5.0000000,
-0.0000000,5.0000000,0.0000000,
-0.0000000,0.0000000,-5.0000000,
-0.0000000,-5.0000000,0.0000000,
-0.0000000,0.0000000,5.0000000,
-0.0000000,5.0000000,0.0000000,
-0.0000000,0.0000000,-5.0000000,
-0.0000000,-5.0000000,0.0000000,
-0.0000000,0.0000000,5.0000000,
-0.0000000,5.0000000,0.0000000,
-0.0000000,0.0000000,-5.0000000,
-0.0000000,-5.0000000,0.0000000,

在Blender中，每个yz平面切片中每个矢量的场方向都相同，如下所示：

但是，在虚幻中，方向似乎有所改变，并且具有恒定方向的切片已移动为xz平面。方向已标记为更加清晰：

我注意到的一件事是轴本身似乎在Blender和Unreal之间交换了。因此，我尝试在xz和yz平面上进行镜像。但是，这不能解决问题，实际上导致第一个示例不正确。因此，我的核心问题是为什么在导入.fga文件时会出现这种不一致的情况，并且这与虚幻引擎在显示之前如何预处理这些文件有关？如果需要的话，文件是使用Python 3生成的。

谢谢！