Virtual Pyro Posted July 15, 2009 Share Posted July 15, 2009 Hey guys, I was interested in finding out a little about making explosions in houdini. I am pretty familiar with using fluids and pyro but I still havent really figured out what is necessary to create an actual explosion. Also, Could someone help explain how to tie my explosion to a rigid body dynamics object please? Im really wanting to advance but there is so little to study online regarding this subject. Any help would be most appreciated as always. Thank you! Hairston Quote Link to comment Share on other sites More sharing options...
essencevfx Posted July 15, 2009 Share Posted July 15, 2009 an expanding particle cloud emitting fuel with point velocity works well, the 'gas released' param. will expand your explosion as well. If you want a larger explosion, advect more fuel. Try emitting a lot of temp and turn down boyancy and then controlling its burn off with a gas dissipate dop.... Quote Link to comment Share on other sites More sharing options...
Virtual Pyro Posted July 15, 2009 Author Share Posted July 15, 2009 (edited) an expanding particle cloud emitting fuel with point velocity works well, the 'gas released' param. will expand your explosion as well. If you want a larger explosion, advect more fuel. Try emitting a lot of temp and turn down boyancy and then controlling its burn off with a gas dissipate dop.... Thank you VERY much for that information. Is it possible to read the houdini docs to learn a little more about these nodes? I have never worked with particle clouds or gas dissipate dops before so it would be helpful for me to read it as it sounds foreign to me Hairston Edited July 15, 2009 by Virtual Pyro Quote Link to comment Share on other sites More sharing options...
essencevfx Posted July 16, 2009 Share Posted July 16, 2009 by particle cloud i just mean create an 'explosion' with particles, and then source your fluid from those points...dissipate dop's not really necessary for you're tests so don't sweat that ... Quote Link to comment Share on other sites More sharing options...
Fomal Posted July 16, 2009 Share Posted July 16, 2009 an expanding particle cloud emitting fuel with point velocity works well, the 'gas released' param. will expand your explosion as well. If you want a larger explosion, advect more fuel. Try emitting a lot of temp and turn down boyancy and then controlling its burn off with a gas dissipate dop.... Ahh, good one! And keyframe as much as you can, gives you more control over the entire simulation process. All the combustion, buyoancy and source emission parameters are a good start Quote Link to comment Share on other sites More sharing options...
Virtual Pyro Posted July 16, 2009 Author Share Posted July 16, 2009 Ahh, good one! And keyframe as much as you can, gives you more control over the entire simulation process. All the combustion, buyoancy and source emission parameters are a good start Hi, Could you point me in the right direction to learn how to acheive this simulation? I would most certainly appreciate it. This is one of the most important things that I want to learn within the visual effects field (explosions). Any help would be highly appreciated. Thank you Hairston Quote Link to comment Share on other sites More sharing options...
essencevfx Posted July 16, 2009 Share Posted July 16, 2009 you need to understand what the combustion model in houdini is doing before tackling an explosion. start out with the fire shelf tool and work with fire first. play with the param's Formal mentioned on the pyro solver node. Once you understand how your getting flame, you can kick that up to an explosion using the particle method. Quote Link to comment Share on other sites More sharing options...
Virtual Pyro Posted July 16, 2009 Author Share Posted July 16, 2009 (edited) you need to understand what the combustion model in houdini is doing before tackling an explosion. start out with the fire shelf tool and work with fire first. play with the param's Formal mentioned on the pyro solver node. Once you understand how your getting flame, you can kick that up to an explosion using the particle method. Ok I understand, that answers one of my questions. I wasnt sure how to initiate the process but now I see that its via pyro solver. I was wondering if you were referring to actual meshes at first but that makes sense. I do have a basic understanding of the pyro solver and how to manipulate the effects of the smoke and flame but I was wanting to know which options would be best for creating such an explosion. I understand that the temp will make it rise faster and that bouyancy will change its direction but im not sure how I make the smoke and fire stop after the effect...It does the right effect but it continues to burn after. Do I manipulate the burn setting? or something else? Thank you for your patience with me. Hairston Edit: "create an 'explosion' with particles, and then source your fluid from those points" This is kind of where im hung up at. Im not sure how to get started with the particles and then source the fluid from the points. Thats where im completely green. Edited July 16, 2009 by Virtual Pyro Quote Link to comment Share on other sites More sharing options...
pclaes Posted July 17, 2009 Share Posted July 17, 2009 (edited) Edit: "create an 'explosion' with particles, and then source your fluid from those points" This is kind of where im hung up at. Im not sure how to get started with the particles and then source the fluid from the points. Thats where im completely green. create explosion with particles means: do it in pops using some initial velocity, wind (noise) and drag particles to fluid: gas particle to field Dop seems easy enough, although for more flexibility, check some of the solutions in this thread: http://forums.odforce.net/index.php?showtopic=9325 (and if you then would want an explosion of colors you could also transfer color attributes from those particles to tint the smoke, but first get the other stuff working. Then have a look at this thread: http://forums.odforce.net/index.php?showto...amp;#entry61907 ) Edited July 17, 2009 by pclaes Quote Link to comment Share on other sites More sharing options...
Virtual Pyro Posted July 17, 2009 Author Share Posted July 17, 2009 create explosion with particles means: do it in pops using some initial velocity, wind (noise) and dragparticles to fluid: gas particle to field Dop seems easy enough, although for more flexibility, check some of the solutions in this thread: http://forums.odforce.net/index.php?showtopic=9325 (and if you then would want an explosion of colors you could also transfer color attributes from those particles to tint the smoke, but first get the other stuff working. Then have a look at this thread: http://forums.odforce.net/index.php?showto...amp;#entry61907 ) Ok, so would I bring in an object and select emit under particles to form a popnet? or would I do something different to get this started. I think its just getting started thats the hardest for me. Again I apologize for my ignorance. Hairston Quote Link to comment Share on other sites More sharing options...
Magnus Pettersson Posted July 17, 2009 Share Posted July 17, 2009 Hey what pclaes means is that you lay down a popnet node (inside a geo container) and then you can eather choose to emit particles from a point or from a source geometry.. if u want to emit from lets say a sphere, you create a sphere and easiest is to plug it into first input of the popnet node and then dive inside the popnet. There you create a source pop and choose "emit from first parameter" and choose to emit from surface random.. if you want to have particles move in the normal direction of your sphere go up to geo level and add add a point sop to the sphere and set it to add normals ... dont forget to have the sphere as mesh or polygon and not a primitive. If you want to emit from a single point then you can just create a popnet and inside that have a location pop... now its time to shape your explosion with initial velocity, forces, drag some noise and so on until your particles behave like an explosion.. then you continue into dop world 2 Quote Link to comment Share on other sites More sharing options...
Virtual Pyro Posted July 17, 2009 Author Share Posted July 17, 2009 Hey what pclaes means is that you lay down a popnet node (inside a geo container) and then you can eather choose to emit particles from a point or from a source geometry.. if u want to emit from lets say a sphere, you create a sphere and easiest is to plug it into first input of the popnet node and then dive inside the popnet. There you create a source pop and choose "emit from first parameter" and choose to emit from surface random.. if you want to have particles move in the normal direction of your sphere go up to geo level and add add a point sop to the sphere and set it to add normals ... dont forget to have the sphere as mesh or polygon and not a primitive.If you want to emit from a single point then you can just create a popnet and inside that have a location pop... now its time to shape your explosion with initial velocity, forces, drag some noise and so on until your particles behave like an explosion.. then you continue into dop world THANK YOU!! Thats EXACTLY what I was asking. This is most helpful. Hairston Quote Link to comment Share on other sites More sharing options...
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