Mesh.RecalculateTangents

Parameters

Description

Recalculates the tangents of the Mesh from the normals and texture coordinates.

After modifying the vertices and the normals of the Mesh, tangents need to be updated if the Mesh is rendered using Shaders that reference normal maps. Unity calculates tangents using the vertex positions, normals and texture coordinates of the Mesh.

RecalculateTangents adds a tangent attribute to the vertex, or changes the tangent attribute to the correct format. The attribute has a dimension of 4 and uses the VertexAttributeFormat.Float32 format. RecalculateTangents adds the attribute even if the Mesh doesn't have any vertices.

using UnityEngine;

public class Example : MonoBehaviour
{
    void Start()
    {
        Mesh mesh = GetComponent<MeshFilter>().mesh;
        mesh.RecalculateTangents();
    }
}

RecalculateTangents converts Mesh vertex position, normal and UV0 data to VertexAttributeFormat.Float32 format, if the format is different.

If the Mesh does not have normals, texture coordinates or triangles, then the tangents are all set to a (1,0,0,1) vector.

Additional resources: RecalculateNormals.