agent-tools/mesh-tool/mesh/transform.go

package mesh

// Apply transforms every vertex by mat. Mirroring transforms (negative
// determinant) flip triangle winding, so it is corrected here to keep
// normals pointing the same way relative to the surface.
func (m *Mesh) Apply(mat Mat4) {
	for i := range m.Verts {
		m.Verts[i] = mat.Apply(m.Verts[i])
	}
	if mat.Det3() < 0 {
		m.FlipWinding()
	}
}

// ApplyAll transforms a set of meshes.
func ApplyAll(meshes []*Mesh, mat Mat4) {
	for _, m := range meshes {
		m.Apply(mat)
	}
}