A problem with project?

[mauvia]

In the following .asy file if I uncomment line A I no longer get the "tube" otherwise created by the last line. Can anyone tell me what the problem is? Is there some incompatibility?

Thanks
Maurizio

import three;
import tube;
import graph3;

currentpicture=new picture;
unitsize(10cm);
currentlight=White;

triple P(real t){return (0,t,0);}
path3 segment=graph(P,-1,1);

path segmentprojected=project(segment);

draw(segment,linewidth(.2));

//draw(segmentprojected); //A

draw(surface(tube(segment,scale(0.05)*unitcircle)),lightgray);

[John Bowman]

You are trying to output 2D graphics to the same file as your 3D graphics. Since version 2.71, Asymptote separates 2D and 3D graphics. If you want both 2D and 3D output, you should shipout to separate fles like this:

~~~unitsize(10cm);
currentlight=White;

triple P(real t){return (0,t,0);}
path3 segment=graph(P,-1,1);

path segmentprojected=project(segment);

draw(segment,linewidth(.2));

picture pic;
unitsize(pic,10cm);;
draw(pic,segmentprojected);
shipout("2D");

draw(surface(tube(segment,scale(0.05)*unitcircle)),lightgray);

~~~