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  1. #1
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    I wanna blow up a car! (but only virtually)

    I'm trying to learn fracture today, and I'm not too happy with the results, so I need some advice. Lightwave is famous for things like BSG, Iron Sky, etc all of which have beautiful explosions. Obviously explosions have other elements, but fracture is part of the process, right? The problem I have is that whatever options I use for fracturing, the mesh ends up a little messed up. In theory a good fracture should leave the model in such a way that is fractured but it doesn't look like it. As you can see in the attached render, the car exterior is not terrible, although a few vertices went crazy, but those can be pushed back inside the car. But inside the car through the glass it looks like Robocop had a panic attack.. This was done with Voronoi, random points at 100 cells. However, I tried all of them, I read the manual to see how each worked, played with different settings and got different results, but the crazy situation inside the car is about the same. This happens with every car I loaded, and these are the cars from http://www.dmi-3d.net/, which are all done in Lightwave, it's not one of those Maya to C4D to Blender to OBJ conversions where many things go awry.

    So those of you who have experience creating high quality explosions, what fracture settings do you use?

    Attachment 116228

  2. #2
    Registered User pinkmouse's Avatar
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    For any of the fracture commands to work without artifacts like that, you need to make sure that every object is a closed solid. So, for instance, if the dashboard is a single poly, it won't fracture well, you need to extrude it to make it 3d.
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  3. #3
    Man of many cells. shrox's Avatar
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    Using that will just look like a 1980's polygonal mess. Break the car into pieces, like the doors, hood, trunk, etc. The morph them into deformed shapes they might have after being involved in an explosion. Then you'll want to either move them manually, or something like HardFX.
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  4. #4
    Adapting Artist jasonwestmas's Avatar
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    yes, metal doesn't shatter like rock, concrete and glass so just take that into consideration. It's more bendy and hard when tossed about by elemental forces.
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  5. #5
    Super Member JonW's Avatar
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    You would want to have it break up in pieces at weak points. As said above the doors blown off, boot, bonnet etc, along weld lines, not the middle of solid things. Also trims and parts stuck on the car, each of these could deform & break into 2 or three bits. A car door would be best to leave as one part but deform because of the pressure of the explosion.

    All the glass would have been blown out at the start. But I guess this would be so fine & fast that a shower of particles flying at the start will be the go.

    Having said all that. If you want to make the car explosion look good. it will actually look nothing like a real explosion. When you see this on TV all you see is a instant cloud of fire & smoke!

    I did read many years ago. Whether this is true or not. But footage from an underground nuclear test captured the manhole cover flying off the hole the bomb was lowered into. Someone did the calculations that the manhole cover would be the furthest manmade object sent into space!
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  6. #6
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    Thanks for the very useful advice. I knew that probably an explosion that looks real would need to fracture different parts of the car separately and bend others (unless the car was made of stone completely) but I wondered why it was so hard to get a fractured that would leave the mesh intact but fractured. I seem to remember I had more success with the fracture tool in Blender, but I don't like that program in the least so I try to stay away from it as much as possible.

    My final goal is to achieve good explosions in space, it blows my mind when I see BSG and I see not only the simple explosions of Vipers and Raiders (which I'm sure are probably more complicated than they look), but even more when I see the big ships explode in several different places and then break apart in tiny pieces. I imagine it must take a lot of planning regarding which layers to fracture and which ones to morph, besides the particles, which I think are called Hypervoxels in Lightwave, right?

  7. #7
    Quote Originally Posted by JonW View Post
    I did read many years ago. Whether this is true or not. But footage from an underground nuclear test captured the manhole cover flying off the hole the bomb was lowered into. Someone did the calculations that the manhole cover would be the furthest manmade object sent into space!
    That's so cool, this could be the start of an animated short. Then we see in deep space the drifting cover hitting an alien craft. Bang.

  8. #8
    I would do first a rough test, a quick violent flash followed by a Hypervoxel explosion turning into black and billowing heavily. When the explosion happens the car can be lifted slightly up in the air.
    I think this effect on 24fps happens so abruptly that you practically see clearly only the burning out.

  9. #9
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    Quote Originally Posted by pinkmouse View Post
    For any of the fracture commands to work without artifacts like that, you need to make sure that every object is a closed solid. So, for instance, if the dashboard is a single poly, it won't fracture well, you need to extrude it to make it 3d.
    I did not know this. Good info. I'm sure I will need to blow something up sometime!

  10. #10
    RETROGRADER prometheus's Avatar
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    You probably might want to check Sean M Jacksons learning series, Explosion, Fire and Smoke Volume I and II.
    I think he worked on battlestar galactica with these kind of effects of exploding ships etc,
    I havenīt seen them up now and Im not sure where they can be purchased from today since kurvs studios vanished?
    https://www.youtube.com/watch?v=ZrV_G9ZxzBk
    https://www.youtube.com/watch?v=kZNp9ni6-sI
    https://www.youtube.com/watch?v=c2VFxt57EJo
    Thereīs more samples on the channel ..browse through them and you might get an idea.

    In the series I think he goes through destroying and preparing the models for exploding parts etc, probably by cutting and pasting parts, using premade debri parts and maybe using morphs to manually explode the parts, not
    sure if he used hardfx for it..maybe.
    Today we have the bullet engine for dynamics, and special fracture tools, but that might not be necessary..the old techniques might still be the most efficient to work with, with fracture in modeler you can also explode to morph.

    thatīs what I believe is the destruction part..for the fire explosion parts I think they used a lot of combination of real explosion footage from some of those bigger reckording studios using real pyro effects, that is comped or mixed in with plates and together
    with hypervoxels particle trails to add direction and further firey motion, in some cases you could probably use purely hypervoxels for explosions too.

    Dj cat kelly myers...I think he had some tutorials similar too, and I think he was involved some way too with some explosion stuff, I do not know where those tutorials are now though, seem to be gone from www.liberty3d.com..you could visit the site
    and contact them, i think it might have been some legal issues about some content for explosions in there...donīt know for sure though.

    So check either Sean M jacksons videos or Kelly myers videos.

    Those spaceshot explosions has their distinct style...but fits mostly there, car explosions will most likely have that rolling smaller pyro cloud..and for that you would like to go with turbulenceFD..visit www.jawset.com for downloading
    and testing the fluid plugin for lightwave with a learning edition.

    You could map fluid simulations, or real life footage on to sprite clips, like using the sprites shading tab and using clips, from there you can load in firesequence or explosion sequences and you can sort of get a realtime openGL feedback
    on where the explosion is and how it looks.


    old dynamite plugin had a great fire shader..but it isnīt available anymore...with some work you might get close with hypervoxels...
    Hereīs a tank explode test...no pieces flying though
    http://vimeo.com/28587261

    Michael

  11. #11
    RETROGRADER prometheus's Avatar
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    You probably might want to check Sean M Jacksons learning series, Explosion, Fire and Smoke Volume I and II.
    I think he worked on battlestar galactica with these kind of effects of exploding ships etc,
    I havenīt seen them up now and Im not sure where they can be purchased from today since kurvs studios vanished?
    https://www.youtube.com/watch?v=ZrV_G9ZxzBk
    https://www.youtube.com/watch?v=kZNp9ni6-sI
    https://www.youtube.com/watch?v=c2VFxt57EJo
    Thereīs more samples on the channel ..browse through them and you might get an idea.

    In the series I think he goes through destroying and preparing the models for exploding parts etc, probably by cutting and pasting parts, using premade debri parts and maybe using morphs to manually explode the parts, not
    sure if he used hardfx for it..maybe.
    Today we have the bullet engine for dynamics, and special fracture tools, but that might not be necessary..the old techniques might still be the most efficient to work with, with fracture in modeler you can also explode to morph.

    thatīs what I believe is the destruction part..for the fire explosion parts I think they used a lot of combination of real explosion footage from some of those bigger reckording studios using real pyro effects, that is comped or mixed in with plates and together
    with hypervoxels particle trails to add direction and further firey motion, in some cases you could probably use purely hypervoxels for explosions too.

    Dj cat kelly myers...I think he had some tutorials similar too, and I think he was involved some way too with some explosion stuff, I do not know where those tutorials are now though, seem to be gone from www.liberty3d.com..you could visit the site
    and contact them, i think it might have been some legal issues about some content for explosions in there...donīt know for sure though.

    So check either Sean M jacksons videos or Kelly myers videos.

    Those spaceshot explosions has their distinct style with pure expansion and retraction and without air compression to advect the explosion...so it fits mostly there, car explosions will most likely have that rolling smaller pyro cloud due to air..and for that you would like to go with turbulenceFD..visit www.jawset.com for downloading
    and testing the fluid plugin for lightwave with a learning edition.

    You could map fluid simulations, or real life footage on to sprite clips, like using the sprites shading tab and using clips, from there you can load in firesequence or explosion sequences and you can sort of get a realtime openGL feedback
    on where the explosion is and how it looks.


    old dynamite plugin had a great fire shader..but it isnīt available anymore...with some work you might get close with hypervoxels...
    Hereīs a tank explode test...no pieces flying though
    http://vimeo.com/28587261

    hereīs an old compare test with some hypervoxels...thanks to bazsa73 and a remake of it I did.
    http://vimeo.com/26508787

    Michael
    Last edited by prometheus; 08-09-2013 at 08:58 PM.

  12. #12
    RETROGRADER prometheus's Avatar
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    Hereīs two explosion presets I made long time ago...(Edited...preset link did not work on first post..fixed)
    http://www.presetcentral.com/preset/42
    http://www.presetcentral.com/preset/429/

    quite old and made for use on single nulls as initial big blast, I would probably recomend using particle emitters with carriers and trailers though...like these.
    http://vimeo.com/45587582
    Last edited by prometheus; 08-09-2013 at 08:56 PM.

  13. #13
    My 2 cents here, not really interested in giving you fracture advise or anything dynamics related, but I suggest you plan the shot out and work out what camera angle you're gonna be working with, and then plan all your destruction to play to that camera. An explosion has so many random and messy elements it's best put together in the composite, where you can cheat using filmed smoke, fire and dust elements to enhance whatever your 3D is doing. Cu-dos if you can do something convincing all in 3D that looks good from all angles, but I'd be trying to do some sleight of hand to pull something like that off.

  14. #14

  15. #15
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    Quote Originally Posted by prometheus View Post
    You probably might want to check Sean M Jacksons learning series, Explosion, Fire and Smoke Volume I and II.
    I think he worked on battlestar galactica with these kind of effects of exploding ships etc,
    I havenīt seen them up now and Im not sure where they can be purchased from today since kurvs studios vanished?
    There should be a law that when a company defrauds its artists, the copyright transfers automatically to the artists. Like in this case, Kurv had a lot of very talented artists do a lot of tutorials for them, didn't pay them a dime (google Kurv Studios rip off and you can read several reports on it) but now there's no chance of getting those tutorials anywhere unless resorting to piracy, in which I would put myself at legal risk, and even my computer if they have a virus. Like two BSG tutorials, one by Kat Myers and another one by Kevin Phillips that I'd love to get my hands on, but they're not for sale anymore. So if there was a law for which the copyright goes back to the author in case of non-payment, they could be free to sell them themselves. That would be the most logical and moral thing to do.

    However, at least Kelly Myers is going to release a tutorial that he told me has some of the techniques of his Kurv Studios tutorial, but applied to Iron Sky, so I'm eager to buy that when it's released, whenever that may be.
    Last edited by Sebasvideo; 08-10-2013 at 08:28 AM.

 

 
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