lovely tip by mr Rowell :) On Sun, May 13, 2012 at 9:57 PM, Paul Schoen <[email protected]>wrote:
> Hey, > > thanks for the useful input using the curve tool as well as the "blurring > the rectangle"-trick. I messed around with the curve tool with something > like this > "CurveTool1.intensitydata.r/CurveTool1.intensitydata.r(start_frame)(in > my case 1)" and put in the gain of the grade node. > > But because the shadows are wandering and do not darken the picture > uniformally, I had no luck with that. So I tried the tip by James Rowell > which works absolutely magnificent because you can adjust the crop > according to the area to be covered and minor local changes are reflected > as well depending on the strength of the blur applied to the crop. You can > even mix different area with aligning several crops together I found out. > > Of course it still needed fine tuning because shadows do not only darken > certain areas but also make them more blue (=cooler)... > > Thanks a lot! > > Paul, Vienna > > > > 2012/5/12 Eetu Martola <[email protected]> > >> >> ------------------------------ >> >> From : James Rowell** >> Subject : Re: [Nuke-users] Analyze Brightness in a Region of Pixels to >> drive Grade Node >> >> >> Hi Paul, >> >> There may be a tool that already does what I'm about to describe, but >> I've done something like what (I think) you want in the past by cropping to >> the small area that you want to analyse then put a sufficient blur on that >> small area to smooth it all out, then reformat the small crop up to a full >> size image. Then, take a "frameHold" on that image on some reference >> frame, then divide the one by the other and you now have a full frame image >> that you can use to multiply against anything else to CC it in a way that >> will mimic the frame by frame difference of your little sampled area over >> the course of the shot, so you can (for example) reproduce flickering, or >> even remove flickering if you flip the order of the inputs on the "divide". >> Anyway, this may give you other ideas too. >> >> Regards, >> James Rowell >> >> ------------------------------ >> *From:* Paul Schoen <[email protected]> >> *To:* [email protected] >> *Sent:* Saturday, May 12, 2012 5:26 AM >> *Subject:* [Nuke-users] Analyze Brightness in a Region of Pixels to >> drive Grade Node >> >> Hello, >> >> this is my first post to the mailing list, so I hopefully get everything >> right in explaining my particular problem: >> >> I have a composite of a Background in which feet are moving over a >> pavement. As they move they make shadows on the pavement. The foreground is >> moving spider that was filmed on the same pavement later on. Now I want the >> brightness of my foreground to change exactly like the shadows of the >> moving feet change the brightness of the pavement in the background. >> >> Long time ago, there was a node in Shake called AnalysePixel or something >> like that which could read out a certain area of pixel over the whole >> length of a shot. With this data one could drive the ColorCorrect-node to >> automatically change the the brightness or any other value. I used it once >> to match a non-flickering shot to a flickering one (NOT FLICKER REMOVAL!!!). >> >> I found nothing similar in Nuke except the Spotmeter-function in the >> Viewer. But I found no hint to read its values and use it in an expression. >> I need something to constantly analyze the brightness over a given range of >> frames in a certain region of pixels and to drive a Grade or >> ColorCorrect-Node with this values via an expression. >> >> Does anyone have any hints on this? I'm using Nuke 6.2v1. >> >> For convenience I uploaded the comp layout: >> http://dl.dropbox.com/u/1891745/dpadb_022_lay_v01.mov >> >> Thanks, >> >> Paul Schoen, Vienna >> >> _______________________________________________ >> 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 > -- __________________________________________________ *Fredrik Pihl - **visual effects supervisor - digital compositor* *UNITED IMAGE CREATORS AB* rönnvägen 11, se-14144 huddinge, sweden +46-708-559 559
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