//a.bvr\na=parametricSurface\na.setMinMax=s,-3,3\na.setMinMax=t,-3,3\na.setEquation=x,(s)\na.setEquation=y,(t)\na.setEquation=z,(1+s+t)\na.setSegmentCount=20\na.color=yellow\na.spawn\n\n//b.bvr\nb=parametricSurface\nb.setMinMax=s,-3,3\nb.setMinMax=t,-3,3\nb.setEquation=x,(s)\nb.setEquation=y,(t)\nb.setEquation=z,(1-s)\nb.setSegmentCount=20\nb.color=blue\nb.spawn\n\n//c.bvr\nc=parametricCurve\nc.setMinMax=t,-3,3\nc.setEquation=x,(-0.5*t)\nc.setEquation=y,(t)\nc.setEquation=z,(1+0.5*t)\nc.setSegmentCount=20\nc.setWidth=0.15,0.15\nc.color=red\nc.spawn\n\n\n\n\n\n