cw85353741 Posted April 25, 2012 Share Posted April 25, 2012 (edited) HI,gays!This effect in Green Lantern,How can make this light effect in houdini , I use particle for this effect ,but my effect was less filiform and details.Who can help me to fix this problem!Thank you This is my work Edited April 25, 2012 by cw85353741 2 Quote Link to comment Share on other sites More sharing options...
cw85353741 Posted April 25, 2012 Author Share Posted April 25, 2012 sorry,pic upload Green Lantern.bmp this is reference (lighteffect3.mov)00.00.01.486.bmp this is my Quote Link to comment Share on other sites More sharing options...
pclaes Posted April 25, 2012 Share Posted April 25, 2012 Looks like you could do that fairly easily with a few stretched out (scaled) fluid sims. Quote Link to comment Share on other sites More sharing options...
cw85353741 Posted April 26, 2012 Author Share Posted April 26, 2012 Hi pclaes,can you tell me more flow about ueing fluid sims!Thank you! Quote Link to comment Share on other sites More sharing options...
pclaes Posted April 26, 2012 Share Posted April 26, 2012 Go to the shelf called Pyro FX, click on the billowy smoke tool, create a container. - It will drop down some nodes. run the sim, scale up the obj in the y direction by 10. It needs 100 frames or so of preroll. Play with the source and, buoyancy and source temperature scale to get desired taste. See scene file. fluidstream_v001.hip Quote Link to comment Share on other sites More sharing options...
tallen Posted April 27, 2012 Share Posted April 27, 2012 oh hey... I was there at Imageworks doing dev on Green Lantern at Sony. The green energy was made three different ways: The light beam was created using a shader, although early tests were created via a myriad of techniques. One of them using volumetric splines common to both Sony (Svea) and DD (Storm). (That's something I'd like to see Sesi begin to embrace. It's been years overdue) The green energy balls fx (surrounding hal) were created predominately with particles and sprites (and instancing) - quite ram intensive (the still you provided had a ton of motion blur in there) And finally, Hal's fast and slow energy was done with geo tricks using facing (camera) ratio fade method. (Think 'trail sop' with 'connect as mesh' option, then 'alpha para' & 'alpha perp' in shading) Fun thing about Green Lantern is that much of the fx can be done with houdini (because most of it was!) But anyone who went to DD or Sony (or R&H) knows about volumetric splining. We could use that in the Sesi repertoire. Quote Link to comment Share on other sites More sharing options...
cw85353741 Posted April 28, 2012 Author Share Posted April 28, 2012 thank you very much! by the way!happy International Workers' Day!! Quote Link to comment Share on other sites More sharing options...
dyei nightmare Posted April 28, 2012 Share Posted April 28, 2012 (edited) no but that light beam is not the most interesting thing in the movie... but this effect is: Edited April 28, 2012 by dyei nightmare 1 Quote Link to comment Share on other sites More sharing options...
Marc Posted May 1, 2012 Share Posted May 1, 2012 But anyone who went to DD or Sony (or R&H) knows about volumetric splining. We could use that in the Sesi repertoire. Yes we could... that would be awesome. Quote Link to comment Share on other sites More sharing options...
eetu Posted May 2, 2012 Share Posted May 2, 2012 (edited) Tell us more Is it "just" a spline curve, rasterized to a voxel grid, or something more ..interesting? Edited May 2, 2012 by eetu Quote Link to comment Share on other sites More sharing options...
sly Posted May 12, 2012 Share Posted May 12, 2012 Tell us more Is it "just" a spline curve, rasterized to a voxel grid, or something more ..interesting? yep ,would like to know too Quote Link to comment Share on other sites More sharing options...
pclaes Posted May 14, 2012 Share Posted May 14, 2012 I don't know the internal details of the way storm works as I have never used it, but as far as I understood it was a rendertime procedural that deforms and samples curves based on noise patterns, I'm not sure any voxelization is happening at all. It seems more similar to that technique where you create a volume through "motion blur". Also the strength of this lies in using curves rather than points so you can interpolate both over time as well as over the parametric coordinates of the curve. I always thought the results looked similar to the "noise puff" you could get with a power noise on a fog sphere. Also, I don't think that technique is really fluid driven. Much closer to advected particles that then have those curve balls applied to them for rendering (still creating tons of extra detail) - I think I saw this in a making of for The day after tomorrow in that tornado sequence by dd. Please elaborate more on how it actually works as I'm curious as well and there are most likely some incorrect assumptions in the way I think it works. Quote Link to comment Share on other sites More sharing options...
Guest xionmark Posted May 15, 2012 Share Posted May 15, 2012 But anyone who went to DD or Sony (or R&H) knows about volumetric splining. We could use that in the Sesi repertoire. Hi Tom, There's a distinction between the "Voxel Bitch" and "Storm", no? Not just historical but evolved tech. The first time I rendered a vb volume in the viewport, and then swing the camera around only to find, a grid! Ah HA! Damn, there's serious optimizations going on in there! --Mark Quote Link to comment Share on other sites More sharing options...
theviolator Posted August 4, 2012 Share Posted August 4, 2012 I have also worked on Green Lantern, and I had to match closely what was done at Sony imageworks. I did several shots matching the green energy using my own rig done in Maya, with blend shaped curves animated with a cluster of them on top of the blendshape animation, emitting millions of particles with tons of turbulence and very little conserve. Quote Link to comment Share on other sites More sharing options...
koen Posted August 5, 2012 Share Posted August 5, 2012 (edited) Magnus and Nafees did a great presentation on some of the techniques behind svea and storm, you can find the pdf here: http://magnuswrenninge.com/volumetricmethods And hopefully his book will be out soon: http://magnuswrenninge.com/volume-rendering/book-soon-to-be-released Cheers, Koen Edited August 5, 2012 by koen Quote Link to comment Share on other sites More sharing options...
jwolverton Posted August 6, 2012 Share Posted August 6, 2012 THANKS!! Nice to be appreciated! Jeff Wolverton no but that light beam is not the most interesting thing in the movie... but this effect is: Quote Link to comment Share on other sites More sharing options...
jwolverton Posted August 6, 2012 Share Posted August 6, 2012 Hey y'all! (I'm Jeff Wolverton, I made the 'battery beam' effect in "Green Lantern" you're talking about.) Without going into to too much detail due to Sony's NDA we sign (*cough* ahem, Tom *cough*) that particular effect (just the battery beam; as Tom mentioned there's a lot of beams in GL done a lot of different ways. But that particular effect is just a shader on a flat plane that's at the camera's near clipping plane. In other words, just a single square facing the camera is rendered. So, how the volumetric-ness? This is the fun part: think of it this way-- you don't have to make an entire ray tracer inside a renderman shader, but do this: at each pixel in screen space, get the location of the near point (point at the near clipping plane), call it A, then the position of the farthest point (far clipping plane, or use a depth map made from the stuff in the scene to stop when you hit stuff.) Call it B. Okay, now we just march from A to B and add up "densities". What's the density? That's the fun part-- it's just 'math in space'! You know the X,Y,Z of where ever you are, and you can compare that to other things passed in to the shader (say... two points that define the centerline of a cylinder, and the radius of that cylinder? Hint, Hint?) Then you can calculate distance to the centerline of the cylinder, and with a little math the "angle around" that that point is, and how far "along" the cylinder it is. The make a density function that is some function of that-- maybe start with a sine wave that goes down the length, then add some noise based on the distance to the centerline, maybe some tangents of sines of cosines... you get the picture-- do a zillion tests until you find a function that looks cool (and addresses notes from your Director and CG sups!) You'll have built up some big collection of tan(sin(distance etc., but it'll run fast (computers like math!) AND, since it's just a simple plane & shader and "math in space", it looks cool no matter how close you get to it (resolution independent, no fluid sim needs, no high voxel resolutions, etc! Computers hate dense volumes iterations; slow!) Math in space on a single plan-- good fun! It leads to all sorts of cool stuff and I'm sure I'm not the first guy to think of the trick. www.JeffWolverton.com sorry,pic upload Green Lantern.bmp this is reference (lighteffect3.mov)00.00.01.486.bmp this is my Quote Link to comment Share on other sites More sharing options...
jwolverton Posted August 8, 2012 Share Posted August 8, 2012 THANKS!! Nice to be appreciated! Jeff Wolverton BTW- this effect (we called it "TMICE" since the description from the script was just something vague like "...and then Tomar Re makes The Most Interesting Construct Ever") is all copies of simple geometric shapes moving around a trefoil (and some of the shapes are trefoils of trefoils, etc.) Just more of the "math in space" tricks that I'm so fond of! I actually made oodles of different TMICE and this one (the one they picked) was about my third favorite. And the world never gets to see the others! Dang! Quote Link to comment Share on other sites More sharing options...
James Jackson Posted August 9, 2012 Share Posted August 9, 2012 Another great volume resource that was announced at Siggraph 2012, DreamWorks Open Vdb. For effects like this. http://www.openvdb.org/ Quote Link to comment Share on other sites More sharing options...
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