Bump mapping

[haggi]

Hi,

for my maya-houdini shader translation tools I need to implement bump mapping.

I had a look at the way houdini does its bump mapping and it seems it simply uses a vop_displaceAlongNormal without moving the point.

My code looks like this:

#include <voptype.h>
#include <voplib.h>

surface testSurface()
{
// ------------------- checker ---------------------------
        vector checkerCol = {0,0,0};
        float contrast = 1.0;
        float count = 8;
        float sTile = floor(s * count);
        float tTile = floor(t * count);
        float res = (sTile+tTile) % 2;
        if( res == 0)
                checkerCol = set(0,0,0);
        else
                checkerCol = set(1,1,1);
// ------------------- bump -------------------------------------
        float sshear = 0;
        float tshear = 0;
        int for_poly = 1;
        int obj_space = 0;
        int bump_only = 1;
        float bumpValue = luminance(checkerCol);
        float bumpDepth = 1.0;
        vector outPoint;
        vector displacedN;
        vop_displaceAlongNormal( P, normalize(N), bumpValue, bumpDepth, sshear, tshear, for_poly, obj_space, bump_only, outPoint, displacedN);

        N = displacedN;
        Cf = displacedN;
}

The checker seems to be okay but the normals are not modified.

Any ideas?

Thanks.

[haggi]

Problem solved. Seems I forgot to include:

#define VOP_SHADING