B样条曲线正算反算贝塞尔曲线拼接曲面车身CAD作业答案.doc

B样条曲线的正算 function Byt8(p0,p1,p2,p3,p4,p5,p6,p7) t=0:0.001:1; %m=[-1 3 -3 1;3 -6 3 0;-3 0 3 0;1 4 1 0]; x=p0(1)*(1/6)*(-t.^3+3*t.^2-3*t+1)+p1(1)*(1/6)*(3*t.^3-6*t.^2+4)... +p2(1)*(1/6)*(-3*t.^3+3*t.^2+3*t+1)+p3(1)*(1/6)*t.^3; y=p0(2)*(1/6)*(-t.^3+3*t.^2-3*t+1)+p1(2)*(1/6)*(3*t.^3-6*t.^2+4)... +p2(2)*(1/6)*(-3*t.^3+3*t.^2+3*t+1)+p3(2)*(1/6)*t.^3; %plot([p0(1) p1(1) p2(1) p3(1)],[p0(2) p1(2) p2(2) p3(2)]); hold on; plot(x,y,r); x=p1(1)*(1/6)*(-t.^3+3*t.^2-3*t+1)+p2(1)*(1/6)*(3*t.^3-6*t.^2+4)... +p3(1)*(1/6)*(-3*t.^3+3*t.^2+3*t+1)+p4(1)*(1/6)*t.^3; y=p1(2)*(1/6)*(-t.^3+3*t.^2-3*t+1)+p2(2)*(1/6)*(3*t.^3-6*t.^2+4)... +p3(2)*(1/6)*(-3*t.^3+3*t.^2+3*t+1)+p4(2)*(1/6)*t.^3; %plot([p0(1) p1(1) p2(1) p3(1)],[p0(2) p1(2) p2(2) p3(2)]); hold on; plot(x,y,r); x=p2(1)*(1/6)*(-t.^3+3*t.^2-3*t+1)+p3(1)*(1/6)*(3*t.^3-6*t.^2+4)... +p4(1)*(1/6)*(-3*t.^3+3*t.^2+3*t+1)+p5(1)*(1/6)*t.^3; y=p2(2)*(1/6)*(-t.^3+3*t.^2-3*t+1)+p3(2)*(1/6)*(3*t.^3-6*t.^2+4)... +p4(2)*(1/6)*(-3*t.^3+3*t.^2+3*t+1)+p5(2)*(1/6)*t.^3; %plot([p0(1) p1(1) p2(1) p3(1)],[p0(2) p1(2) p2(2) p3(2)]); hold on; plot(x,y,r); x=p3(1)*(1/6)*(-t.^3+3*t.^2-3*t+1)+p4(1)*(1/6)*(3*t.^3-6*t.^2+4)... +p5(1)*(1/6)*(-3*t.^3+3*t.^2+3*t+1)+p6(1)*(1/6)*t.^3; y=p3(2)*(1/6)*(-t.^3+3*t.^2-3*t+1)+p4(2)*(1/6)*(3*t.^3-6*t.^2+4)... +p5(2)*(1/6)*(-3*t.^3+3*t.^2+3*t+1)+p6(2)*(1/6)*t.^3; %plot([p0(1) p1(1) p2(1) p3(1)],[p0(2) p1(2) p2(2) p3(2)]); hold on; plot(x,y,r); x=p4(1)*(1/6)*(-t.^3+3*t.^2-3*t+1)+p5(1)*(1/6)*(3*t.^3-6*t.^2+4)... +p6(1)*(1/6)*(-3*t.^3+3*t.^2+3*t+1)+p7(1)*(1/6)*t.^3; y=p4(2)*(1/6)*(-t.^3+3*t.^2-3*t+1)+p5(2)*(1/6)*(3*t.^3-6*t.^2+4)... +p6(2)*(1/6)*(-3*t.^3+3*t.^2+3*t+1)+p7(2)*(1/6)*t.^3; %plot([p0(1) p1(1) p2(1) p3(1)],[p0(2) p1(2) p2(2) p3(2)]); hold on; plot(x,y,r); plot([p0(1) p1(1) p2(1) p3(1) p4(1) p5(1) p6(1) p7(1)],[p0(2) p1(2) p2(2) p3(2) p4(2) p5(2) p6(2) p7(2)]); 执行： Byt8([0,0],[1,4],[3,9],[5,7],[6,2],[7,6],[9,5],[11,3]) B样条曲线的反算 function Byangtiao8(p) t=0:0.005:1; hold on fo