Hi David, here is my suggestion: http://owl3d.com/tests/svg-developers/notknot.svg
For smooth movement of the car, mpath is a copy of the highway, same d attribute without the internal M jumps. 2 clipped copies of the highway are used as bridges and their opacity is synchronized with the car travel. Do I get an extra credit for this? :) BTW, the Celtic knot is a Tubefy demo in the normalGradient article: http://owl3d.com/svg/tubefy/articles/article3.html#poi Warmest regards, Israel --- In [email protected], "ddailey" <ddai...@...> wrote: > > In this example: http://srufaculty.sru.edu/david.dailey/svg/notknot2.svg > I see the following results: > IE/ASV and FF4 agree with me about the timing... > Opera seems to synchronize the declarative animation differently between the > application of the mask and the vehicles... > Safari and Chrome do not seem to activate the animation of the mask. > > Background story can be seen here: > http://srufaculty.sru.edu/david.dailey/svg/knots.html, it leads into the > above experiment and to some of the following concerns: > Let's limit our consideration to the FF4 and IE+ASV version (since they did > what I intended -- not that that is right of course -- I think one could > simply change the timing and make it work in Opera instead) > > 1. I was pleased to be able to simulate a knot using a single path, since the > semantics makes sense. My previous forays into the subject (at above link) > had various problems associated with both semantics and the size of the DOM. > I was also pleased with how a couple of simple re-uses of that path (like > some of the vector effects techniques I suppose) suffice to simulate a fill > and a texture to the road. > > 2. The blue car goes under the underpass and over the overpass as it should, > though the red car doesn't. This is due to a trick: I gave the bridge magical > properties and put the car under its spell. Specifically, the car has a mask > applied (as a sort of inverse clipPath -- Doug Schepers says he's opened a WG > issue on the issue of inverse clipPaths) based on a "subpath"* of the road > and the mask animates between white and black in a way planned to synchronize > with the car's approach to the bridge. The bridge doesn't know that the car > is approaching**, it is just synchronized through a common time interval on > the SMIL loop. The red car is under the same influence of the mask, but the > mask has not been programmed for the red car's arrival. > > 3. Can anyone think of an easier way to do this? What if the cars are all > moving at different speeds that have perhaps been randomized? > > 4. One could build the road as a series of segments and then have the car > leap from segment to segment, and change its stacking order within the DOM as > it goes -- but that would be rather script heavy, semantically inaccessible > and distinctly inelegant. > > 5. Is Opera or FF and ASV right on the timing? I hope for the latter simply > since I don't want to have to rethink my bridges. > > cheers > David > > * One can think of subpaths as unioned into a "superpath". Vector effects in > SVG 1.2 covers a part of this. > ** Though it might be nice to be able to determine that without have to > calculate it through script or paper and pencil but to expose the animated > values. > > [Non-text portions of this message have been removed] > ------------------------------------ ----- To unsubscribe send a message to: [email protected] -or- visit http://groups.yahoo.com/group/svg-developers and click "edit my membership" ----Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/svg-developers/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/svg-developers/join (Yahoo! ID required) <*> To change settings via email: [email protected] [email protected] <*> To unsubscribe from this group, send an email to: [email protected] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
