Thanks for all the replies. I've got my head around the format, but I cannot seem to get a 1D prelut for lin2log. If anyone is willing to share a generic prelut for lin2log that would be much appreciated. I would love a way via something similar to the GenerateLUT node to write out a 1024 prelut with our own lin2log if anyone has some cool ideas for that.
thx Dan On Wed, Jun 26, 2013 at 11:26 PM, Torax Unga <[email protected]> wrote: > It is actually similar to a .csp lut. > Here is a made up lut: > > Version 3 > Format any > Type 3D+1D > From 0 10 > To 0 1 > Black 0 > White 1 > Length 2 11 > LUT: > Pre { > 0.0 > 0.1 > 0.2 > 0.3 > 0.4 > 0.5 > 0.6 > 0.7 > 0.8 > 0.9 > 1.0 > } > 3D { > 0.000000 0.000000 0.000000 > 0.212500 0.212500 0.212500 > 0.715400 0.715400 0.715400 > 0.927900 0.927900 0.927900 > 0.072100 0.072100 0.072100 > 0.284600 0.284600 0.284600 > 0.787500 0.787500 0.787500 > 1.000000 1.000000 1.000000 > } > Basically it takes a linear input with values from 0 to 10, remaps it to 0 > to 1 with a curve made out of 11 steps, then applies a 2x2 cube (3d lut) > that takes all the saturation out. > Don't have Mplay here, so can not test. > ------------------------------ > *From:* Ben Dickson <[email protected]> > *To:* Nuke user discussion <[email protected]> > *Sent:* Wednesday, 26 June 2013, 21:23 > *Subject:* Re: [Nuke-users] Re: Houdini preLUTs > > The HDK docs should explain the format of the prelut: > > http://www.sidefx.com/docs/hdk11.0/hdk_io_lut.html > > Additionally, OCIO's FileFormatHDL.cpp might be of use to clarify some > things. It is quite heavily commented, and has some test cases at the > end of the file which contain small example LUT's: > > > https://github.com/imageworks/OpenColorIO/blob/master/src/core/FileFormatHDL.cpp > > > On 27/06/13 13:42, Dan Rosen wrote: > > I don't have an OCIO environment set up. So I'd like to feed in a custom > > shaper lut file or simply copy and paste it in. Is there a command line > > way to feed a shaper lut file vs setting it in an OCIO environment? I > > don't think there is. I"ll send an example of what I've got tomorrow as > > I'm not currently in the office. It's just a matter of format in the > > shaper lut values. > > > > I'm sure it would benefit me in the log run to set up the OCIO > > environment. One small thing is that we have a custom lin2log at our > > facility. Do you have a generic Houdini lut, with a lin2log in the pre > > lut, that you could share so I could look at the formatting? > > > > Thanks, > > Dan > > > > On Wednesday, June 26, 2013, Alex - wrote: > > > > What sort of problem are you having? > > We have been using ociobakelut to create houdini.lut files with > > working 1D shapers/preluts without any issues. > > > > Your example looks pretty correct. > > > > > > On Thu, Jun 27, 2013 at 8:57 AM, Dan Rosen <[email protected] > > <javascript:_e({}, 'cvml', '[email protected]');>> wrote: > > > > Hello there, > > > > I'm looking for some help to generate Houdini linear LUTs. We > > are using ociobakelut a bit and can convert luts to Houdini > > format, but the header, specifically the log2lin Pre (LUT) is > > proving difficult. If anyone has any insight and or python that > > might be useful to share that would be much appreciated. > > > > I know that the header is something like this, but with the > > format of the Pre (LUT) part is where I'm getting tripped up. > > > > Version 3 > > Format any > > Type 3D+1D > > > From 0 10 > > To 0 1 > > Black 0 > > White 1 > > Length [cube_size] [prelut_size] > > LUT: > > Pre { > > [val] > > [val] > > : > > [val] > > } > > 3D { > > [r] [g] [b < > http://www.sidefx.com/docs/hdk10.0/_r_e___o_g_l_8h.html#0f71581a41fd2264c8944126dabbd010 > >] > > [r] [g] [b < > http://www.sidefx.com/docs/hdk10.0/_r_e___o_g_l_8h.html#0f71581a41fd2264c8944126dabbd010 > >] > > : > > [r] [g] [b < > http://www.sidefx.com/docs/hdk10.0/_r_e___o_g_l_8h.html#0f71581a41fd2264c8944126dabbd010 > >] > > } > > > > > > _______________________________________________ > > Nuke-users mailing list > > [email protected] <javascript:_e({}, 'cvml', > > '[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 > > -- > ben dickson > 2D TD | [email protected] > rising sun pictures | www.rsp.com.au > _______________________________________________ > 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 >
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