Hello, To be honest, I think you're both right : it's probably not worth the time, especially considering I don't even have a month to setup everything properly in each scene and then render it. And only a handful of frames would actually benefit from that. I barely tried the dynamic framework solution, as, as you mention Stefan, it seems to only really work on fixed-length strands, as well as setting up some flex/stretch I don't really want. And devling deeper into the system looked time-consuming.
However I believe I was quite near the result I wanted, going back to the simple Closest Location to strandposition compound. Maybe I could find the middle solution and smooth the strands whenever they leave the volume to fix the little dents appearing here and there. I have no idea how to smooth a strand, though... Olivier 2015-01-02 15:14 GMT+01:00 [email protected] <[email protected]>: > > > > On 2 Jan 2015, at 12:39, Stefan Kubicek <[email protected] > > <mailto:[email protected]> > wrote: > > > > > > PS: If the runners trails are meant as a graphical element rather > than an > > actual physical element in your picture I doubt I will look nice when it > > collides with the runner. > > > > > > Agreed. I doubt it would give you a look that you want and probably isn’t > worth > spending too much time trying to make a robust system to make it work. Do > a few > quick tests first to see if it’s going to take you in the right direction. > > As a quick alternative, why not try setting the StrandColor to black for > any > strand points that fall inside your collision geometry, and then > incorporate > that as a multiply operation into your shader? That'll hide any parts of > the > strand that go inside your character. > > A > > > > On 02 January 2015 at 12:39 Stefan Kubicek <[email protected]> wrote: > > > > Hi Olivier, > > > > I think there are example scenes for strand collision that ship with > XSI. No > > friction between strands and geo is modeled as far as I can remember, > but it > > might get you started. > > > > Then there is also the strand collision framework for more accurate > > collisions, but I don't know how it reacts to changing point counts and > strand > > length: http://softimage.tv/strand-collision-framework/ > > > > PS: If the runners trails are meant as a graphical element rather than > an > > actual physical element in your picture I doubt I will look nice when it > > collides with the runner. Maybe you could solve this in comp and get > around > > explaining collisions entirely? > > Here is a nice example in a recent Glassworks spot that might be > similar to > > what you to try to achieve: > > http://softimage.tv/lycra-moves-you/ > > > > Good luck, > > > > Stefan > > > > > > > > > > > > Hello, long time reader, first time poster here! > > > > > > > > > So I have a bit of a problem on my hands. > > > > > > > > > We are doing a very simple concept, a sportsman whose back is leaving > > > strand trails as he goes. This is child's play so far. > > > My issue is that we would like the trails to interact with the mesh > when, > > > for various reasons, he cuts through them again. > > > IE : at some point he falls to the ground and stands back up. The > unwanted > > > behaviour is that the strands generated from the back of his head will > > > simply go through his head as he rises up, resulting in a somehow > vertical > > > strands column masking his face and fore-body. The desired behaviour > is that > > > the strands will flow around his cranium, maybe along his back, > effectively > > > leaving at least his face apparent. > > > > > > > > > Animation is done in Maya and transfered over via geocache. > > > > > > I tried to operate with tools like 'closest location' or 'get > location by > > > raycast' applied to the strandpositions when inside the volume to > simulate > > > collision, but these were all lacking. The raycast solution may be > > > promising, but I don't know how to set the correct direction vector. > And > > > sometimes the animation I'm working with may "skip" a strandposition, > > > effectively not triggering the 'inside volume' condition. > > > > > > > > > So yeah basically I don't know how to do that in a visually pleasing > way. > > > If anyone had some pointers, I'd be very grateful ! > > > > > > Thanks, > > > Olivier > > > > > > > > > > > > > > > > > -- > > > > ----------------------------------------------------- > > Stefan Kubicek <a href="mailto:"[email protected]"; > > <[email protected]>">[email protected] > > ----------------------------------------------------- > > Alfred Feierfeilstraße 3 > > A-2380 Perchtoldsdorf bei Wien > > Phone: +43 (0) 699 12614231 > > www.keyvis.at <http://www.keyvis.at> > > This email and its attachments are > > confidential and for the recipient only > > > > > > >
