Okay, so I've got a heightmap yadda yadda, and I've been trying all day to get the bloody normal generations to work. I'm not doing anything fancy - just trying to calculate normals per surface (triangle primitives) and everything goes bonkers:
The problem is the normals are ending up skewed for one reason or another, and I can't seem to figure out for the life of me why. The dark patches are areas that the normals are pointing away from the light (they aren't culled or anything). All the vertices are ordered clock-wise properly. All the vector math is hand-coded and checked.
Here's the code in question, since there's no way you'll be able to work anything out without it:
for (int ix = 0; ix != x; ix++) {
for (int iz = 0; iz != z; iz++) {
{
cVector v[3];
v[0].set( ix *w+xOff,func->call(ix, iz) +yOff, iz *h+zOff);
v[1].set((ix+1)*w+xOff,func->call(ix+1,iz) +yOff, iz *h+zOff);
v[2].set( ix *w+xOff,func->call(ix, iz+1)+yOff,(iz+1)*h+zOff);
cVector v01 = v[0] - v[1];
cVector v02 = v[1] - v[2];
cVector vn;
vn.p_x = v01.p_y * v02.p_z - v01.p_z * v02.p_y;
vn.p_y = v01.p_z * v02.p_x - v01.p_x * v02.p_z;
vn.p_z = v01.p_x * v02.p_y - v01.p_y * v02.p_x;
float L = sqrtf(vn.p_x*vn.p_x + vn.p_y*vn.p_y + vn.p_z*vn.p_z);
vn.p_x /= L;
vn.p_y /= L;
vn.p_z /= L;
glNormal3f(v01.p_x,v01.p_y,v01.p_z);
glTexCoord2f(0,0); glVertex3f(v[0].p_x,v[0].p_y,v[0].p_z);
glTexCoord2f(1,0); glVertex3f(v[1].p_x,v[1].p_y,v[1].p_z);
glTexCoord2f(0,1); glVertex3f(v[2].p_x,v[2].p_y,v[2].p_z);
}
{
cVector v[3];
v[0].set((ix+1)*w+xOff,func->call(ix+1,iz) +yOff, iz *h+zOff);
v[1].set((ix+1)*w+xOff,func->call(ix+1,iz+1)+yOff,(iz+1)*h+zOff);
v[2].set( ix *w+xOff,func->call(ix, iz+1)+yOff,(iz+1)*h+zOff);
cVector v01 = v[0] - v[1];
cVector v02 = v[1] - v[2];
cVector vn;
vn.p_x = v01.p_y * v02.p_z - v01.p_z * v02.p_y;
vn.p_y = v01.p_z * v02.p_x - v01.p_x * v02.p_z;
vn.p_z = v01.p_x * v02.p_y - v01.p_y * v02.p_x;
float L = sqrtf(vn.p_x*vn.p_x + vn.p_y*vn.p_y + vn.p_z*vn.p_z);
vn.p_x /= L;
vn.p_y /= L;
vn.p_z /= L;
glNormal3f(v01.p_x,v01.p_y,v01.p_z);
glTexCoord2f(1,0); glVertex3f(v[0].p_x,v[0].p_y,v[0].p_z);
glTexCoord2f(1,1); glVertex3f(v[1].p_x,v[1].p_y,v[1].p_z);
glTexCoord2f(0,1); glVertex3f(v[2].p_x,v[2].p_y,v[2].p_z);
}
}
}
We can assume that the coordinates generated are correct, since the terrain renders correctly (superimposed sinusoidal waves). The problem lies in the normal calculations, somewhere.
If there's anything else that you need to help me, just ask and I'll post it up. No point in me posting up everything, as this (it seems to me) is the only relevant code.
Thanks [sad]
