SurfSmoothNormal

Calculates the smooth surface normals.

Syntax

IppStatus ipprSurfSmoothNormal_32f(const Ipp32f* pVertNorm, const Ipp32s* pIndexNorm, const Ipp32s* pTrngl, const Ipp32f* const pHit[2], Ipp32f* pSurfNorm[3], int len, IpprIndexType ippInd);

Parameters

pVertNorm

Pointer to the vertex normals.

pIndexNorm

Pointer to the normals' indexes.

pTrngl

Pointer to the triangles' indexes.

pHit

Pointer to the array of pointers to the local surface parameter (u, v) planes at the hit point if the intersection is found.

pSurfNorm

Pointer to the array of pointers to separate coordinate (x, y, z) planes of surface normals at intersections points.

len

Number of rays in the block.

ippInd

Specifies the type of indexing; the following values are possible:

ippNormInd	using an array of normals indexes;
ippTriInd	using an array of the triangles' indexes.

Description

The function ipprSurfSmoothNormal is declared in the ippr.h file. This function calculates the surface's smooth normals in the points of intersection of rays with triangles. The function used the linear interpolation of per vertex normal in the intersection point according to the following formulas (in vector representation):

If for triangle ABC, aN, bN, cN are per vertex normals, and u, v are barycentric coordinates, then

uN = aN *u + (1- u) *cN;

vN = bN *v + (1- v) *cN;

uvN = aN *u + bN *v + (1-(u + v )) *cN

Return Values

ippStsNoErr	Indicates no error. Any other value indicates an error or a warning.
ippStsNullPtrErr	Indicates an error condition if one of the specified pointers is `NULL`.