sebkaine Posted February 9, 2015 Share Posted February 9, 2015 (edited) Hi Guys, I would like to achieve this kind of effects inside H. http://roberthodgin.com/additionsubtraction/ http://roberthodgin.com/wired-magazine/ Basically it looks that it is a Vector Field Visualisation using LIC Methods + Color remapping. The concept is describe here : http://en.wikipedia.org/wiki/Line_integral_convolution http://web.mit.edu/viz/EM/visualizations/resources/cabral.pdf I would be curious to get some expert POV on the most efficient and straightforward way to achieve this in H. - Full VEX ? - POP ? - DOP ? Any input or previous Hip reference of something similar would be great ! Thanks for your lights ! Cheers E Edited February 9, 2015 by sebkaine Quote Link to comment Share on other sites More sharing options...
Guest mantragora Posted February 9, 2015 Share Posted February 9, 2015 There was a guy couple years ago that used Fields from DOPS. I can't find it right now and to be fair I don't remember who it was but they looked exactly like what you want. But you can check this topic for ideas => http://forums.odforce.net/topic/10928-hair-system/ 1 Quote Link to comment Share on other sites More sharing options...
sebkaine Posted February 9, 2015 Author Share Posted February 9, 2015 Thanks a lot for your very quick feedback Mantragora , the link is very interesting ! Quote Link to comment Share on other sites More sharing options...
Guest mantragora Posted February 9, 2015 Share Posted February 9, 2015 There was even article about this. It was around the time when Houdini got first Volume DOPS, so around 2010. I remember him because he had one of the first websites that used this cool Microsoft Labs technique for zooming big images (you all know it probably from Google Earth). I exchanged couple words with him so I now that he used OpenZoom project for displaying his gallery. Maybe someone remembers him? Quote Link to comment Share on other sites More sharing options...
Guest mantragora Posted February 9, 2015 Share Posted February 9, 2015 Found him => http://forums.odforce.net/user/4062-0rr/ Take a look at his Flickr => https://www.flickr.com/photos/deskriptiv/ 1 Quote Link to comment Share on other sites More sharing options...
icarus Posted February 9, 2015 Share Posted February 9, 2015 (edited) I did similar technique to generate thesehttp://www.popkafx.com/wp/?cat=6 I originally tried to advect many particles through a static velocity field and made connected trails but ended up using the volume trail sop to generate the lines in a cheaper fashion. To get the high fidelity output I would resample these trails and stamp them to a volume. Some of the volumes were over 2k resolution so I would iteratively generate new lines and add them to the high-res volume at small particle scale. At render time I would use a ramp based on density to create color variety and tweak the values post-render. Edited February 9, 2015 by icarus 3 Quote Link to comment Share on other sites More sharing options...
mawi Posted February 9, 2015 Share Posted February 9, 2015 (edited) You can get rather cool patterns by drawing vectors on a plane, convert it to a volume, smooth it out and then volume trail points in it. velField.hipnc Edited February 9, 2015 by mawi 3 1 Quote Link to comment Share on other sites More sharing options...
sebkaine Posted February 9, 2015 Author Share Posted February 9, 2015 (edited) Thanks a lot for all your feedback guys ! @Raymond very cool result @Martin your setup is extremely cool ! very light, no computation, very beautiful result ... i love it ! @Mantragora the occluded rendering are extremely elegant ... great ref I think i will try to mix an hybrid approach with particles and curves. If you have any other ideas or tricks i am still curious. I think one important aspect is to be able to - create animated force field that evolve throw time , with expension / retraction / vorticity of the several fields - normalise the vectors of the field generated - generate curves that follow those vectors - generate particles that propagate along those vectors - keep simulation time very low / very fast A mix of cv+point could be cool for the rendering ! some cool links : http://web.cse.ohio-state.edu/~hwshen/hwshen/FlowVis.html http://www.paraview.org/Wiki/ParaView/Line_Integral_Convolution http://www.zhanpingliu.org/research/flowvis/flowvis.htm Edited February 9, 2015 by sebkaine Quote Link to comment Share on other sites More sharing options...
eetu Posted February 9, 2015 Share Posted February 9, 2015 Deskriptiv is the awesomest ever. I dunno how many tabs of their stuff I have open on my work computer at the moment, but it's not a small number.. Quote Link to comment Share on other sites More sharing options...
sebkaine Posted February 9, 2015 Author Share Posted February 9, 2015 I find that those 3 types of pass are pretty cool : // cv streamline http://www.zhanpingliu.org/research/flowvis/Streamlines/ActiveFLOVE03.bmp // advected point http://www.zhanpingliu.org/research/flowvis/LIC/LIC_Variations/Flow4z_ELIC_CW.GIF // volumetric ghosting http://www.zhanpingliu.org/research/flowvis/VAUFLIC/Snapshots/Cut04__299_311.JPG Quote Link to comment Share on other sites More sharing options...
0rr Posted February 9, 2015 Share Posted February 9, 2015 Deskriptiv is the awesomest ever. I dunno how many tabs of their stuff I have open on my work computer at the moment, but it's not a small number.. Thanks man . Glad you like my stuff. Quote Link to comment Share on other sites More sharing options...
ranxerox Posted February 9, 2015 Share Posted February 9, 2015 you might also want to look into the vdb advect points sop. There is a pretty good example of how to use it on the open vdb site. under "examples.zip" : http://www.openvdb.org/download/ -G Thanks a lot for all your feedback guys ! @Raymond very cool result @Martin your setup is extremely cool ! very light, no computation, very beautiful result ... i love it ! @Mantragora the occluded rendering are extremely elegant ... great ref I think i will try to mix an hybrid approach with particles and curves. If you have any other ideas or tricks i am still curious. I think one important aspect is to be able to - create animated force field that evolve throw time , with expension / retraction / vorticity of the several fields - normalise the vectors of the field generated - generate curves that follow those vectors - generate particles that propagate along those vectors - keep simulation time very low / very fast A mix of cv+point could be cool for the rendering ! some cool links : http://web.cse.ohio-state.edu/~hwshen/hwshen/FlowVis.html http://www.paraview.org/Wiki/ParaView/Line_Integral_Convolution http://www.zhanpingliu.org/research/flowvis/flowvis.htm 2 Quote Link to comment Share on other sites More sharing options...
sebkaine Posted February 9, 2015 Author Share Posted February 9, 2015 Thanks for the input gregory , i'm gonna check this. VDB could also offer me the possibility to get my volumetric ghosting pass. i have play with Martin idea in simple cube , it already give fun result. test_001.hipnc Quote Link to comment Share on other sites More sharing options...
sebkaine Posted February 9, 2015 Author Share Posted February 9, 2015 VDB give very good stuff ! Thanks again for the idea Gregory , very fast , very light , i love the idea ! a second test with VDB : test_002.hipnc 1 Quote Link to comment Share on other sites More sharing options...
ranxerox Posted February 11, 2015 Share Posted February 11, 2015 yes VDB is pretty incredible. -G VDB give very good stuff ! Thanks again for the idea Gregory , very fast , very light , i love the idea ! a second test with VDB : Quote Link to comment Share on other sites More sharing options...
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