11

I constructed the technical figure embedded below. I wonder how to draw red arc to denote angle $\alpha$ between two blue vectors. (Actually, I add the desired output using Inkscape.)

enter image description here

The Asymptote code is pasted below.

import three;
import graph3;
size(200);

pen solid=linetype(new real[]);
pen longdashed=linetype(new real[] {10,8});
pen dashed=linetype(new real[] {3,8});

currentprojection=perspective(1/2,-1/4,1/4.4);

pen bg=gray(0.9)+opacity(0.1);
draw(surface((0,0,0.5)--(1,0,0.5)--(1,1,0.5)--(0,1,0.5)--cycle),bg);

draw((0,0,0)--(1,0,0), solid);
draw((0,0,0)--(0,1,0), longdashed);
draw((1,0,0)--(1,1,0), solid);
draw((0,1,0)--(1,1,0), longdashed);
draw((0,0,1)--(1,0,1), solid);
draw((0,0,1)--(0,1,1), solid);
draw((1,0,1)--(1,1,1), solid);
draw((0,1,1)--(1,1,1), solid);
draw((0,0,0)--(0,0,1), solid);
draw((1,0,0)--(1,0,1), solid);
draw((1,1,0)--(1,1,1), solid);
draw((0,1,0)--(0,1,1), longdashed);
draw((0.5,0,0.5)--(0.5,1,0.5));
draw((0,0.5,0.5)--(1,0.5,0.5));
draw((0,0,0)--(1,1,1),dashed);
draw((1,0,0)--(0,1,1),dashed);

// Blue vectors
draw((0.5,0.5,0.5)--(1,1,1),blue,Arrow3);
draw((0.5,0.5,0.5)--(1,0.5,0.5),blue, Arrow3);
10

enter image description here

Change the end of your MWE to

// Blue vectors
guide3 v1=(0.5,0.5,0.5)--(1,0.5,0.5);
guide3 v2=(0.5,0.5,0.5)--(1,1,1);
draw(v1,blue,Arrow3);
draw(v2,blue,Arrow3);
guide3 alphaArc=arc(point(v1,0),point(v1,0.5),point(v2,0.5));
draw(alphaArc,red,Arrows3);

label("$\alpha$",alphaArc,SE);
label("$e_1$",point(v1,1),SE);
label("$e_2$",point(v2,1),SE);

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.