bool tri::intersect(ray & _r, float & t) {
//calculate t first
t = inner_product(p[0] - _r.origin, nrml) / inner_product(_r.dir, nrml);
if (t < 0)
return false;
//check inside the tri
point x = _r.get_t(t);
vect v2_1 = p[1] - p[0];
vect v3_2 = p[2] - p[1];
vect v1_3 = p[0] - p[2];
vect vx_1 = x - p[0];
vect vx_2 = x - p[1];
vect vx_3 = x - p[2];
/*special judge for debug
if(abs(x.x) > 500 || abs(x.z) > 500)
return false;
return true;
*/
if (inner_product(cross_product(v2_1, vx_1), nrml) > 0
&& inner_product(cross_product(v3_2, vx_2), nrml) > 0
&& inner_product(cross_product(v1_3, vx_3), nrml) > 0) {
return true;
}
return false;
}
