Hi list, I’m trying to produce figures like this, showing motion as a series of snap-shots, with the earlier moments more faint.
PastedGraphic-1.pdf
Description: Adobe PDF document
Here are three examples of metafun code using transparency and “decorated".
\startMPinclusions
picture ball;
ball := image(
draw fullcircle scaled 1cm
withshademethod "circular"
withshadecenter (.25,.25)
withcolor "lightgray" shadedinto black;
draw fullcircle scaled 1cm withpen pencircle scaled 0.8pt;);
\stopMPinclusions
\starttext
\startMPpage
draw decorated (draw ball) withtransparency (1,.2);
draw decorated (draw ball shifted (1cm, 0cm)) withtransparency (1,.4);
draw decorated (draw ball shifted (4cm, 0cm)) withtransparency (1,.6);
draw ball shifted (9cm, 0cm);
\stopMPpage
\startMPpage
draw decorated (draw ball) withtransparency (1,.2);
draw decorated (draw ball shifted (0.25cm, 0cm)) withtransparency (1,.4);
draw decorated (draw ball shifted (1cm, 0cm)) withtransparency (1,.6);
draw ball shifted (2.25cm, 0cm);
\stopMPpage
\startMPpage
draw decorated (draw ball) withtransparency (1,.2);
filldraw fullcircle scaled 1cm withcolor white withpen pencircle scaled 0.8pt
shifted (0.25cm, 0cm);
draw decorated (draw ball shifted (0.25cm, 0cm)) withtransparency (1,.4);
filldraw fullcircle scaled 1cm withcolor white withpen pencircle scaled 0.8pt
shifted (1cm, 0cm);
draw decorated (draw ball shifted (1cm, 0cm)) withtransparency (1,.6);
draw ball shifted (2.25cm, 0cm);
\stopMPpage
\stoptext
Transparency alone does a good job if the objects don’t overlap (first
example). If they do overlap, it’s kind of a mess (second example). I get a
much better result if I put a white circle behind each transparent ball so that
they look lighter without showing the earlier objects through them (third
example). However, that solution is going to be difficult for more complex
shapes. I tried drawing the shape using “redecorated () withcolor white", to
draw the white background object, but only the outline appears white. The
circular shading disappears altogether, leaving the ball fill area transparent.
I also tried to use something like “softened .8” but could not get that to
produce any output.
Any ideas?
Thanks!
Gavin___________________________________________________________________________________ If your question is of interest to others as well, please add an entry to the Wiki! maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context webpage : http://www.pragma-ade.nl / http://context.aanhet.net archive : https://bitbucket.org/phg/context-mirror/commits/ wiki : http://contextgarden.net ___________________________________________________________________________________
