ID3DXMATRIXStack::LoadIdentity method (D3DX10.h)
Loads identity in the current matrix.
This method has no parameters.
If the method succeeds, the return value is D3D_OK. If the method fails, the return value can be D3DERR_INVALIDCALL.
The identity matrix is a matrix in which all coefficients are 0.0 except the [1,1][2,2][3,3][4,4] coefficients, which are set to 1.0. The identity matrix is special in that when it is applied to vertices, they are unchanged. The identity matrix is used as the starting point for matrices that will modify vertex values to create rotations, translations, and any other transformations that can be represented by a 4x4 matrix.