Hi, I’d like a presentation progress indicator that looks like a boat on waves – and if it works, it can also become a bike on hills or a mars rover on dunes. But my math skills are lacking. Below’s a mostly working draft. * I find the waves not yet very convincing. Would it make sense to use a randomized sinus? (How?) * The boat should sit on the middle wave and be rotated by the current slope. I know I need the “time” of the upper curve and get the 1st derivation, but how? """ \setuppapersize[SW] \startuseMPgraphic{Waves} numeric height,stops,yoffset; stops := 10; height := OverlayHeight/10; path wave; draw (0,0)--(OverlayWidth,0)--(OverlayWidth,OverlayHeight) withcolor white withpen pencircle scaled 0.01; for j=1 upto 3: definecolor [name="Sea", y=(j/20), c=2*(j/10), m=(j/20)]; yoffset := height/(j*2); wave := (0,0)--(0,yoffset)... for i=1 upto stops: (OverlayWidth*i/(stops+1), (yoffset) randomized (height/2)) ... endfor (OverlayWidth,yoffset)--(OverlayWidth,0)--cycle; fill wave withcolor "Sea"; endfor; pair pos; pos := (OverlayWidth * RealPageNumber/NOfPages, height/2 randomized 2); path ship; ship := (0,10)---(70,10)...(60,0)---(10,0)...cycle; fill ship xysized (10,5) shifted pos rotatedaround (pos, 15) withcolor red; \stopuseMPgraphic \defineoverlay[Waves][\useMPgraphic{Waves}] \setupbackgrounds[state=repeat] \setupbackgrounds[page][background={Waves}] \starttext \dorecurse{10}{\recurselevel\page} \stoptext """ Hraban