线段和空间三角形交点请另外判断

线段和空间三角形交点请另外判断 //线段和空间三角形交点请另外判断 point3 intersection(line3 l,plane3 s){ point3 ret=pvec(s); double t=(ret.x*(s.a.x-l.a.x)+ret.y*(s.a.y-l.a.y)+ret.z*(s.a.z-l.a.z))/ (ret.x*(l.b.x-l.a.x)+ret.y*(l.b.y-l.a.y)+ret.z*(l.b.z-l.a.z)); ret.x=l.a.x+(l.b.x-l.a.x)*t; ret.y=l.a.y+(l.b.y-l.a.y)*t; ret.z=l.a.z+(l.b.z-l.a.z)*t; return ret; } point3 intersection(point3 l1,point3 l2,point3 s1,point3 s2,point3 s3){ point3 ret=pvec(s1,s2,s3); double t=(ret.x*(s1.x-l1.x)+ret.y*(s1.y-l1.y)+ret.z*(s1.z-l1.z))/ (ret.x*(l2.x-l1.x)+ret.y*(l2.y-l1.y)+ret.z*(l2.z-l1.z)); ret.x=l1.x+(l2.x-l1.x)*t; ret.y=l1.y+(l2.y-l1.y)*t; ret.z=l1.z+(l2.z-l1.z)*t; return ret; } //计算两平面交线,注意事先判断是否平行,并保证三点不共线! line3 intersection(plane3 u,plane3 v){ line3 ret; ret.a=parallel(v.a,v.b,u.a,u.b,u.c)?intersection(v.b,v.c,u.a,u.b,u.c):intersection(v.a,v.b,u.a,u.b,u.c); ret.b=parallel(v.c,v.a,u.a,u.b,u.c)?intersection(v.b,v.c,u.a,u.b,u.c):intersection(v.c,v.a,u.a,u.b,u.c); return ret; } line3 intersection(point3 u1,point3 u2,point3 u3,point3 v1,point3 v2,point3 v3){ line3 ret; ret.a=parallel(v1,v2,u1,u2,u3)?intersection(v2,v3,u1,u2,u3):intersection(v1,v2,u1,u2,u3); ret.b=parallel(v3,v1,u1,u2,u3)?intersection(v2,v3,u1,u2,u3):intersection(v3,v1,u1,u2,u3); return ret; } //点到直线距离 double ptoline(point3 p,line3 l){ return vlen(xmult(subt(p,l.a),subt(l.b,l.a)))/distance(l.a,l.b); } double ptoline(point3 p,point3 l1,point3 l2){ return vlen(xmult(subt(p,l1),subt(l2,l1)))/distance(l1,l2); } //点到平面距离 double ptoplane(point3 p,plane3 s){ return fabs(dmult(pvec(s),subt(p,s.a)))/vlen(pvec(s)); } double ptoplane(point3 p,point3 s1,point3 s2,point3 s3){ return fabs(dmult(pvec(s1,s2,s3),subt(p,s1)))/vlen(pvec(s1,s2,s3)); }