} else {
xinc = 1;
t = -1 / (ray[0][0] - ray[1][0]);
yinc = (ray[1][1] - ray[0][1]) * t;
zinc = (ray[1][2] - ray[0][2]) * t;
min = w.minPxcor();
max = w.maxPxcor();
xi = min;
yi -= yinc * ray[0][0] * scale - (min * yinc);
zi -= zinc * ray[0][0] * scale - (min * zinc);
}