Question

JavaScript => public var tangents: Vector4[];
C# => public Vector4[] tangents;

Description 描述

The tangents of the mesh.

网格的切线。

Tangents are mostly used in bump-mapped shaders. A tangent is a unit length vector that follows mesh surface along horizontal (U) texture direction. Tangents in Unity are represented as Vector4, with x,y,z components defining the vector, and w used to flip the binormal if needed.

切线主要用于带法线着色器。切线是一个有方向的单位长度向量，沿着网格表面指向水平（U）纹理方向。在Unity中切线被描述为Vector4，x,y,z组件定义的向量，如果需要，及w用来翻转副法线。

Unity calculates the other surface vector (binormal) by taking a cross product between normal and tangent, and multiplying result by tangent.w. Thus w should always be 1 or -1.

Unity通过计算向量和法线的叉乘来计算其他表面的向量（副法线），并乘以tangent.w。因此w应该总是1或者-1。

You should calculate tangents yourself if you plan to use bump-mapped shaders on the mesh. Assign tangents after assigning normals or using RecalculateNormals.

如果你计划在网格上用凹凸贴图着色器，你应该自己计算切线。在赋值法线或者用RecalculateNormals之后再赋值切线。

Mesh