exploding house model - suggestions? - Simply Maya User Community

# 1 14-06-2005 , 02:09 PM

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exploding house model - suggestions?

i shot a movie, and at the end a brick building in the bg will explode. the shot of the explosion will cut from the real building to the model as it explodes and pieces fly out - bricks, wood etc., all in one take, still camera.

so i'm trying to figure out the best way to go about it. i've taken the still of the real building, and applied those textures to a poly model. so if you cut between the real one/model it looks almost the same (at that exact angle). now i'm breaking up the sides into a brick pattern with the split poly tool. when it blows those pieces will fly off. i think i'll place poly bricks and debris at certain places within the model and have them shoot out.

does this sound like it'll work? i could also make up the building out of little bricks and stack them, but if i don't apply the pre-existing texture to the whole facade, it'll look strage when it cuts from the real building to the model. that's why i'm thinking apply the texture to one large plane, and break it up from there.

any other suggestions? also exactly how do i seperate the faces of the poly from each other, so they can fly apart? and how should i convert from the flat plane to 3D bricks once it explodes?

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# 2 14-06-2005 , 02:17 PM

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like this

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# 3 14-06-2005 , 02:41 PM

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Well you can model it any way you like: one objects, many bricks and windows, whatever. You can make the transition seamless by using a camera projection, and then creating a texture reference. That way when you animate all of your little objects, they will have bits of a texture map that come from the original piece. I recently hace to to a whole city block being torn down and reconstructed, and this was how I did it.

Is that clear or do you need me to outline the steps?

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# 4 14-06-2005 , 03:04 PM

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you should definatley use projection mapping to get the original plate on there as a reference as dann said. You will never be able to seamlessly match it if you don't. As for your explosion fake it, you don't need to model each brick invdividually just give the impression. So model a few bits of debris to throw around, cut up your original geo etc.

Also you need to remember what's going to appear once the dust has settled? what's behind the bricks? you will need to paint another projection map of the destroyed building to go in behind.

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# 5 14-06-2005 , 04:39 PM

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could you go through the steps for projection mapping? it sounds like a good way to go.
the reference picture i'd be using is like the one above. for the explosion i think it'll be concentrated on the 2nd/3rd floors of the main building, so it'll explode out, and maybe the roof'll cave in. i think i'll put in an initial flash, so a glow shoots out from all the windows before it explodes. it's a quick shot, maybe...50 frames max. then a cut back to it once it's done, lots of smoke billowin out, so the inside won't be too clear, but it would be cool to see some interior details, maybe some more things fall and collapse...

and again once i've used the split polygon tool to divy up sections of the wall, how do i seperate them? i'm not sure what that action/tool is called.

thanks for your help guys.

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# 6 15-06-2005 , 05:59 AM

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Sure.

1) Create a new Lambert Shader. Set the Ambiant to pure white, and the diffuse to 0.

2) Add a texture to the color channel WITH a projection node.

3) Graph your Lambert and select the Projection node. Set the projection type to Perspective and under Camera Projection Attributes link to your camera.

4) You should lock the translate and rotate of this camera so it never gets moved by accident.

5) Select your models (you can use as many objects as you like), and assign the new Lambert.

6) Under the Rendering set of menus, activate Texturing>Create Texture Reference Object.

Maya has now create _reference objects that are dupes of your models. These are the models that are actually being projected onto. The version of your model you will "explode" will look at the reference for it's texture coordinates.

7) Again, should lock the translate, rotate and scale of the reference camera so it never gets moved by accident. You can hide it too.

Now if you mode the main models, they will maintain the proper texture mapping.

I hope I didn't miss anything. Let me know if this works.

8) Oh yeah, open up the Effects tab on the projection node and set the filter to 0 so Maya doesn't rasterize your texture map.

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# 7 15-06-2005 , 08:21 AM

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thanks, it seems to have worked, i'll keep playing with it.

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# 8 15-06-2005 , 10:53 AM

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Great thread guys. I find this sort of stuff very interesting . . even though I'm not at this level user added image

Cheers
Paul

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# 9 16-06-2005 , 12:32 PM

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everything's coming along well, but i noticed when i rendered that the fragments of the building didn't keep their texture. instead they adopted the texture of whatever they pass over. behind my building is a white sky, so as the pieces fly off they become white...

any idea why? i tried going through the steps again, but same result.

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# 10 16-06-2005 , 01:12 PM

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you need to make sure you do the texture reference objec that dann mentioned otherwise your elements are flying "through" your projection rather than stucking to it

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Currently working on: Your Highness

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# 11 16-06-2005 , 03:02 PM

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i must be missing something, i've gone through the steps over and over but the result is the same. here're some details though, maybe you'll understand why -

when i create the texture reference object, only one little flat brick appears highlighted orange, not the whole building. it seems to be the first poly in the hierarchy of the hypergraph. is it correct that i simply highlight every part of the building, then select "create texture reference object"?

i decided to re-texture reference the building after keyframing all the moving parts. would this change anything?

otherwise i can't imagine what i'm doing wrong...any help very much appreciated.

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# 12 16-06-2005 , 03:15 PM

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wait i realized i was creating the texture reference object wrong, i redid it and made sure the whole building gets referenced, now it seems to be working. a few polys were giving me trouble but once i made sure they got properly referenced it looks fine.

Last edited by astrocalder; 16-06-2005 at 03:22 PM.

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exploding house model - suggestions?

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