D3DXComputeNormals function

Article
03/15/2021

Computes unit normals for each vertex in a mesh. Provided to support legacy applications. Use D3DXComputeTangentFrameEx for better results.

Syntax

HRESULT D3DXComputeNormals(
  _Inout_       LPD3DXBASEMESH pMesh,
  _In_    const DWORD          *pAdjacency
);

Parameters

pMesh [in, out]

Type: LPD3DXBASEMESH

Pointer to an ID3DXBaseMesh interface, representing the normalized mesh object.

pAdjacency [in]

Type: const DWORD*

Pointer to an array of three DWORDs per face that specify the three neighbors for each face in the created progressive mesh. This parameter is optional and should be set to NULL if it is unused.

Return value

Type: HRESULT

If the function succeeds, the return value is S_OK. If the function fails, the return value can be one of the following: D3DERR_INVALIDCALL, D3DXERR_INVALIDDATA, E_OUTOFMEMORY.

Remarks

The input mesh must have the D3DFVF_NORMAL flag specified in its flexible vertex format (FVF).

A normal for a vertex is generated by averaging the normals of all faces that share that vertex.

If adjacency is provided, replicated vertices are ignored and "smoothed" over. If adjacency is not provided, replicated vertices will have normals averaged in from only the faces explicitly referencing them.

This function simply calls D3DXComputeTangentFrameEx with the following input parameters:

D3DXComputeTangentFrameEx( pMesh,
                           D3DX_DEFAULT,
                           0,
                           D3DX_DEFAULT,
                           0,
                           D3DX_DEFAULT,
                           0,
                           D3DDECLUSAGE_NORMAL,
                           0,
                           D3DXTANGENT_GENERATE_IN_PLACE | D3DXTANGENT_CALCULATE_NORMALS,
                           pAdjacency,
                           -1.01f,
                           -0.01f,
                           -1.01f,
                           NULL,
                           NULL);

Requirements

Requirement	Value
Header	D3DX9Mesh.h
Library	D3dx9.lib