David Gary Posted May 24, 2004 Share Posted May 24, 2004 So... You asked for challenges... For procedural minds , If and only if you have time! 1)Break a piece of geometry in shards ( each shard is not a single primitive but a group of primitives , which is much mooore difficult to achieve) 2)Animate the shards with a particle network ( so it's not just instancing...). sorry i didn't post a more complex animation, but ut's just to show the concept 3)Plus ( that's what i did) : the division of the piece must be procedural ( to have control over crack patterns, that is you must define procedurally the groups of primitives). EVERYTHING MUST BE PROCEDURAL sorry for the adGif logo. I do not create animated GIFs very often! Quote Link to comment Share on other sites More sharing options...
meshsmooth Posted May 24, 2004 Share Posted May 24, 2004 Ok crack up a torous then Quote Link to comment Share on other sites More sharing options...
David Gary Posted May 25, 2004 Author Share Posted May 25, 2004 Of Course! It doesn't depend on the object. (if animatedGif slow down the display on odforce, i will make it a link). Quote Link to comment Share on other sites More sharing options...
David Gary Posted May 25, 2004 Author Share Posted May 25, 2004 Or a head ! :) Quote Link to comment Share on other sites More sharing options...
bobster Posted May 28, 2004 Share Posted May 28, 2004 Okay Mr FrenchOP, Please disclose brain power. The ice breaking tutorial is easy enough but for the life of me I can't figure out how to group the primitives, but then I'm fairly new to Houdini. I'm sure I'll kick myself when I find out. Thanks Quote Link to comment Share on other sites More sharing options...
TheDunadan Posted July 1, 2004 Share Posted July 1, 2004 I'd appreciate a hint concerning the following: can a single group SOP output multiple groups or a fuse SOP do multiple seperate fusions ?! Defining the pattern for the actual groups seems easy enough for me, and I think I know how I could create a script that simply creates a seperate fuse or group SOP for each fragment, but having all these seperate fuse / group OP's doesn't sound like an elegant solution to me / has little procedural beauty . Quote Link to comment Share on other sites More sharing options...
anakin78z Posted July 1, 2004 Share Posted July 1, 2004 I'd appreciate a hint concerning the following: can a single group SOP output multiple groups Try the partition sop to do that Quote Link to comment Share on other sites More sharing options...
TheDunadan Posted July 1, 2004 Share Posted July 1, 2004 I should have studied the online help more carefully, thanks Anyhow, it's now working more or less. Once I'm more happy with the pattern I'll post my solution. Jens Quote Link to comment Share on other sites More sharing options...
Jostein Posted July 14, 2004 Share Posted July 14, 2004 Yo guys! Did any of you crack this challenge? I am working on my master's project at the moment - basing much of my particle stuff on the ice breaker (with basher object) - and I would really like to be able to group the primitives into different sized chunks. Question: wouldn't it be possible to create a lumamap in COPs (some kind of shattermap) and using the pic()-function, grouping and fusing primitives based on this information? ANY input on this is extremely welcome! Cheers, jostein. Quote Link to comment Share on other sites More sharing options...
halion Posted July 14, 2004 Share Posted July 14, 2004 I tried working on this last night for about 4 hours and didn't get anywhere. I tried using the facet to make everything unique and then group primitives to form the shapes I want. Problem is I could figure out how to fuse the primitives together to be one big chunck instead of 5 individual ones. But this gives you no easy way to control the crack patterns anyways so back to the drawing board. Quote Link to comment Share on other sites More sharing options...
Lukich Posted July 27, 2004 Share Posted July 27, 2004 Hey, guys! Did anybody solve this challenge - it remains a big mystery to me, no matter how hard i tried FrenchOP, please, show us your magic!!! Quote Link to comment Share on other sites More sharing options...
TheDunadan Posted July 27, 2004 Share Posted July 27, 2004 I wasn't really happy with my solution and I'm going to do a hopefully nice/cleaner setup, but anyhow ...: I created an extra attribute on the points of the grid and using a VEX SOP I simply applied a slightly modified voronoi kinda noise on this attribute: the voronoi noise has a bit of this cobblestone look. So far so good... now I used the Partition SOP to create the unique groups based on this . I don't know anymore if I created primitive or point groups, but I used something similar to the following roule: "point ("/obj/Ice/IceBr", $PT, "myCustomAttribute", 0)" Using the trick Sebarrik suggest in his "prim sort otl" I did a loop, through all the groups and animated these that way. Unfortunally my noise would generate numbers ranging from as low as 00001 up to 99999 (--> ugly group names) no matter if I'd have only 7 groups created via the partition using these values or 1000. Looping though all those non-existant groups was very inefficient and therefore I created an intermediate attribute and tried several simple hash functions to create somewhat unique numbers ranging only from 0 - 4 * times the number of unique groups the partition SOP would create. Trouble is, for proper hashing you usually need some collision resolving and I don't know how to do so using the expression language in Houdini. Anyhow anyone who's intrested in the hashing theory can get a good introduction on this subject in the good old "Introduction To Algorithms" by Cormen. In the end using this "hashed" groups some of the initial groups got fused and therefore a fair bit of trial and error was required when playing with the hasing functions. Well, I guess FrenchOP has a nicer solution for this If I find my old scene file I'll post it. Jens Quote Link to comment Share on other sites More sharing options...
plan9 Posted August 20, 2004 Share Posted August 20, 2004 late reply, but here is a hint.... check the apprentice CD for a hip file named explode.hip... think thats the name of it. look and ye shall recieve... Quote Link to comment Share on other sites More sharing options...
David Gary Posted November 24, 2004 Author Share Posted November 24, 2004 I'M BACK I'M BACK I'M BACK I'M BACK I'M BACK I'M BACK Hi Guys! I had no Internet connection since June 2004 !!!! ( long holiday at remote places with no Internet ( or just mail ) and many problems to get my connection back with f..ing french providers - Not working in an office.. ) Now, I have it back! I'm gonna explain everything. And more! ( I will do a Three-Parts Video Tutorial with general concepts for doing this kind of FX and some others like - creating a fluid flow through a L-system ( for lava flow - blood flow) - "peeling" a surface with arbitrary peels ( often needs math). Just give me time! ( and luck with Internet! ) Quote Link to comment Share on other sites More sharing options...
Rafal123 Posted November 24, 2004 Share Posted November 24, 2004 cool, we r waitin' Quote Link to comment Share on other sites More sharing options...
David Gary Posted November 29, 2004 Author Share Posted November 29, 2004 Hi guys! I spent my Sunday afternoon struggling with my computer to do a correct ( and even good sometimes) video tutorial for the Breaking Objects effect ( no error allowed while recording myself in realtime). Sorry for my -sometimes- ugly akzent. The other tutorials are coming soon ( the Avalon Fx is almost done) The main concept of this three or four-part tutorial is copying operations, that is instancing an operation ( or several ) applied to pre-defined parts of an object. Click here to watch the tut! ( sorry it weigh so much! ) Quote Link to comment Share on other sites More sharing options...
Lukich Posted November 30, 2004 Share Posted November 30, 2004 Beutifully done, FrenchOp!!! Very elegant! Quote Link to comment Share on other sites More sharing options...
Jason Posted December 1, 2004 Share Posted December 1, 2004 Beutifully done, FrenchOp!!! Very elegant! 15218[/snapback] I agree - very nicely done. A lot of advanced Houdini ideas in there, very well put together. Quote Link to comment Share on other sites More sharing options...
meshsmooth Posted December 1, 2004 Share Posted December 1, 2004 That is a fantastic tute. I like the line on your page "Excuse-me if my English is sometimes uncorrect." You should have sead "incorrect" but it adds a beautiful single sentence of self contained irony. Please don Quote Link to comment Share on other sites More sharing options...
Moose Posted December 2, 2004 Share Posted December 2, 2004 Nice little tut! Just wanted to pass on my thanks also. Eveything was clearly demonstrated and I learnt something. Thanks for sharing. Quote Link to comment Share on other sites More sharing options...
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