thanks Guys, thing is- viewing the motion vector layers (positive and negative space) and checking the values with my values indicates it's all normal- no extreme values as we're seeing. It really seems like a bug or a glitch. I'm a comp TD and have been working with Nuke for a few years, so I can say that with a fair degree of certainty. No unpremult operations happening on the motion vectors- only a two stage erode setup. I'll keep trying different things to see what I can do.
cheers, Jordan On Sat, Jul 7, 2012 at 12:56 AM, Ryan O'Phelan <[email protected]> wrote: > I would try eroding the motion vectors a pixel or two less than your color > and alpha, then comping it back in using a smaller and slightly blurred > alpha. > > Hope that helps. > > Ryan > > On Jul 6, 2012 3:25 AM, "Joe Laude" <[email protected]> wrote: >> >> Off the top of my head, first thing I'd check is if your vector channel is >> antialiased and getting unpremulted somewhere. That could give you really >> high values along the edges where it's getting divided by the alpha. >> >> Joe Laude >> Sent from my iPhone >> >> On Jul 5, 2012, at 11:05 PM, Jordan Olson <[email protected]> wrote: >> >> > Hey guys! >> > I'm compositing a CG character at the moment with DOF (using depth >> > channel) and also plugging in motion vectors into a nuke Vector Blur >> > node. As I'm applying DOF first, (relatively soft)- I like to expand >> > the motion vector channels outside the character's initial alpha using >> > an erode (both in positive and negative space). This usually works >> > fine for us, but THIS time I'm getting a really strange spikey >> > artifact. Clamping has no effect on it. >> > >> > Now I've attached an image (100kb), not sure if it'll stay attached to >> > this email through the mailing list, but it's a screenshot of the >> > issue in question. >> > If I toggle the erode/expand gizmo I have on the motion vectors, >> > turning it off does solve the spikey issue, but then I'm back to >> > square one! I need to expand the motion vectors and this has always >> > worked before. >> > >> > Any ideas what could be causing the vector blur to freak out on the >> > alpha edges and give random spikey anomalies? >> > cheers, >> > Jordan >> > <vectorblur_artifact.jpg> >> > _______________________________________________ >> > Nuke-users mailing list >> > [email protected], http://forums.thefoundry.co.uk/ >> > http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users >> _______________________________________________ >> Nuke-users mailing list >> [email protected], http://forums.thefoundry.co.uk/ >> http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users > > > _______________________________________________ > Nuke-users mailing list > [email protected], http://forums.thefoundry.co.uk/ > http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users _______________________________________________ Nuke-users mailing list [email protected], http://forums.thefoundry.co.uk/ http://support.thefoundry.co.uk/cgi-bin/mailman/listinfo/nuke-users
