nMolson Posted June 7, 2012 Share Posted June 7, 2012 I posted this on the Sidefx forums but didnt get much of a response, figured id ask here.. so im starting production on a dam break shot for my final project piece in school. Basically im going to try to reproduce this shot by Method at the 00:30 mark I have 2 and a half months to do the shot and its pretty daunting. I figured id get some opinions from you guys into my current questions and any pointers you guys want to point out would be great. My current plan (vague as it may be) is to run an initial rbd sim of the dam collapsing with objects smashing through in certain areas for the main stress points that water will break through first. the sim will be set up with some sort of magnet force or wind to push the rbds out some what like the water would. then run the water sim through it with the rbds as passives but use Vops/ point clouds to update the velocity/ position of the RBD pieces based on the water. Does this sound like a decent approach? comments? concerns? is this the worst plan you ever heard? Other questions -Flip fluids? these are the only water experience i have in houdini and i have that sidefx waterfall tutorial to back me up so i figured they could work out, but iv never tried using them at this scale before. are they the way to go or should i be looking into SPH? (Id worry i dont have time to learn SPH) -Growing cracks Should i find a way to grow the cracks up and base my fracture off of those (is there a best way to do that) or should i fracture and do the initial collapse sim, then use those break points/cracks to add more debris/cracking in another sim and comp that over -Arches on the dam if i was to incorporate those arches on the top of the dam, which i plan on doing.. should this piece be modeled separately and glued onto the rest of the Geo or should it all be built in one piece, i figure if it was all one piece the stress/breaking points wouldnt be as accurate. id love to hear all thoughts and ideas on this, its the biggest shot iv ever attempted and i know there is a lot of aspects i havent thought of. thanks -Nick Quote Link to comment Share on other sites More sharing options...
Filipp Elizarov Posted June 7, 2012 Share Posted June 7, 2012 For large scale Water sim you've got only 1 way - Using a Flip Fluids - it will give you a nice control and speed.But I think Method in their shots used a distribution simulation it will help a lot but you need a render farm to doing it.For foam and splashes you can use similar techniques which used in Waterfall tutorial. Quote Link to comment Share on other sites More sharing options...
nMolson Posted June 7, 2012 Author Share Posted June 7, 2012 Flip fluids it is, im not sure we'll have a houdini farm set up but il look into the distributed sims if we get it going. for the Bulk of the water would it at all be a good idea to scale down the scene and in turn have less water and faster sim/render then do the more detailed surface/sprays at normal scale? or should it all be proper scale at all times, i know the water acts differently depending on scale, im not sure how much i can get away with Quote Link to comment Share on other sites More sharing options...
Filipp Elizarov Posted June 7, 2012 Share Posted June 7, 2012 Scale scene to small size doesn't decrease simulation time.If you want to change scene size from meters(by defaul) to centimeters - and divide each parameter to 100 to get same result which you have in meters system (you can't to get it) because keep in mind when you change inches system you will change solver works. I think a good idea to work in normal meters system , for best result do not doing a scene size 10 cm and 500 meters. You need to start to doing something.After start you can find a lot of problems , but here we can solve them together.Lets start and post your progress here. Trying to find HOU203 and HOU204 from FXPHD it really can help you. Quote Link to comment Share on other sites More sharing options...
nMolson Posted June 7, 2012 Author Share Posted June 7, 2012 If the resolution of the sim (particle size?) is the same, wouldn't a smaller scale take less particles to fill up and less time to compute? Im still finishing up the model/previz and then il be starting with the rigid Body sims, which im sure will be hard as well, good to know i have support here, thank you il up-load progress as it comes. Il look for those tutorials now Quote Link to comment Share on other sites More sharing options...
ryew Posted June 8, 2012 Share Posted June 8, 2012 If the resolution of the sim (particle size?) is the same, wouldn't a smaller scale take less particles to fill up and less time to compute? Yes, but also resulting in less apparent detail. If you want a high level of detail, you'll still need to scale your particle size relative with the scale of your scene size to sell the effect. Less particles = less detail. You can quickly see this by making a box of FLIP fluid and dropping a RBD ball in it, changing the particle size to see the difference in the splash detail that results. Quote Link to comment Share on other sites More sharing options...
nMolson Posted June 9, 2012 Author Share Posted June 9, 2012 Yes, but also resulting in less apparent detail. If you want a high level of detail, you'll still need to scale your particle size relative with the scale of your scene size to sell the effect. Less particles = less detail. You can quickly see this by making a box of FLIP fluid and dropping a RBD ball in it, changing the particle size to see the difference in the splash detail that results. ah its relative that makes perfect sense. so is it all just finding a balance of how many particles your machine can handle? unfortunately i don't have much time to test with the fluids as im modeling/texturing and starting rigid bodies now. Progress to come soon, thanks everyone Quote Link to comment Share on other sites More sharing options...
nMolson Posted June 16, 2012 Author Share Posted June 16, 2012 So iv started fluid tests in scene with the proper Geo in place and i can already see these sim times are going to kill me.. so im wondering if i can mix particle sizes in the same container? id like to have a low res base sim to fill as much of the volume as i can get away with and have smaller particles riding the surface to make it look nicer. im also going to try meta balls or standard particles with a particle fluid surface as a base and have them as a static object for the flips to interact with.. A super early emorphous blob test render... very low res water and both sim and render time are brutal... panic starts to set it... 10 weeks left, a ton of work to do Quote Link to comment Share on other sites More sharing options...
nMolson Posted July 26, 2012 Author Share Posted July 26, 2012 (edited) Been a while, heres a very short look at what the waters looking like right now... this stream is the first burst as one section gives out. this is only the particle fluid surface, there will be particle foam/spray around it as well im struggling trying to get the water to looks like its emmiting with pressure behind it and also i cant get the water to kind of spread out like the pressure is forcing it out in any direction it can get out... any ideas/ tips? Edited July 26, 2012 by nMolson Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.