arrowheads

Alphabetical index

After having provided an elementary arrowhead for use in 3^d in ..Shapes..Graphics / arrowheads, we now turn to the considerably trickier 3^d arrowheads. The reason things become tricky is that flat arrowheads in 3^d must have the surface normal pointing more or less towards the viewer in order for the arrowhead to be visible, and it is not always that easy to see what is a good normal direction, possibly after the objects has been transformed. Sometimes, the same object will be drawn from different angles, and then it may even be impossible to find a normal direction that suits both viewing angles. In these situations one can either use multiple arrowheads with different normals, or more general non-flat arrowheads, or resort to using facing (see related documentation for examples).

twoCirclesArrow
p::§Path3D ahLength:void::§Length ahAngle:30°::§Float → (> picture::§Drawable3D cut::§Length <)
Dynamic references:	none
This arrowhead is the only attempt so far to make an arrowhead in 3^d completely without need to specify a normal direction. The arrowhead will be constructed as two circles to remind of a cone.

triangleArrow
p::§Path3D normal:(0,0,1)::§FloatTriple ahLength:void::§Length ahAngle:30°::§Float fillAsStrokeing:true::§Boolean → (> picture::§Drawable3D cut::§Length <)
Dynamic references:	none
The arguments have similar interpretation to their meaning in MetaPostArrow. The arrowhead will not bend with the path, compare ..Shapes..Graphics..triangleArrow, but another important difference to MetaPostArrow is that this arrowhead consists of two perpendicular flat arrowheads instead of just one. This makes it less important to find a good normal direction, but the result will often not look as clean.