1.已知三维空间一点P(x1,y1,z1),将其沿向量n(x,y,z)方向,移动距离d,求移动后P'的坐标(x2,y2,z2)?
2.如果不止一个点P,而是三维空间点集Mi(xi,yi,zi),i=0,1,2……n,每个点都有自己的法向量ni(xi,yi,zi),将每个M,沿每个对应的n,移动距离d,则移动后Mi'的坐标是多少?
单点情况
x1 = 1;
y1 = 1;
z1 = -1;
x = 1;
y = 0;
z = 1;
d = 2;
P = [x1;y1;z1];
N = [x;y;z];
Pp = P + d*N/norm(N)
结果:
Pp =
2.4142
1.0000
0.4142
点集情况
M = [1 2 3 4 5
1 2 3 4 5
1 2 3 4 5];
N = [1 -1 0 2 3
0 1 2 0 1
0 0 1 0 1 ];
Mp = M + d*N/sqrt(sum(N.^2))
结果:
Mp =
2.1770 3.1770 4.1770 5.1770 6.1770
1.8003 2.8003 3.8003 4.8003 5.8003
1.4828 2.4828 3.4828 4.4828 5.4828