ID3DXPRTEngine::ComputeDirectLightingSH

Computes the direct lighting contribution to 3D objects where the source radiance is represented by a spherical harmonic (SH) approximation.

HRESULT ComputeDirectLightingSH(
  UINT Order,
  LPD3DXPRTBUFFER pDataOut
);

Parameters

Order

[in] Order of the SH evaluation. Must be in the range of D3DXSH_MINORDER to D3DXSH_MAXORDER, inclusive. The evaluation generates Order² coefficients. The degree of the evaluation is Order - 1.

pDataOut

[in, out] Pointer to an output ID3DXPRTBuffer object that models the direct lighting contribution with the SH approximation. This buffer must have the proper number of color channels allocated for the simulation.

Return Values

If the method succeeds, the return value is D3D_OK. If the method fails, the return value can be one of the following: D3DERR_INVALIDCALL, E_OUTOFMEMORY.

Remarks

The output does not include albedo, and only incoming light is integrated in the simulator. By not multiplying the albedo, you can model albedo variation at a finer scale than the source radiance, thereby yielding more accurate results from compression.

Call ID3DXPRTEngine::MultiplyAlbedo to multiply each precomputed radiance transfer (PRT) vector by the albedo.

Requirements

Header: Declared in D3dx9mesh.h.