How to go about an explosion

[supremepizza]

My questions are as follows:

1) How do I go about modeling the scene (an .avi file) in Maya in order to mask it later?

2) What's the best way to get a nice realistic explosion with smoke and some debris (program and way)?

3) What's the best way to composite the 3D with the video?

There is also a title that I have to animate coming out of the smoke towards the camera. How should I tackle that challenge?
Well I don't know too much but I can help a little. I'm working on my first Live Action/3d Comp myself. This sub-forum has been so quiet lately I can hear crickets.:sad: So maybe we can help each other out

1a) Take some screenshots of your video. I use Permeire Pro. so for me it was...
File->Export->Frame

1b) Lense correct the image
make sure all verticle lines are verticle and all horizontal lines are horizontal as would be seen in real life There is a filter built into Adobe Photoshop CS2 for this but you won't find it in previous versions. So you may need to do a Transform->Perspective

1c) Find your horizon
Draw lines in photoshop (in a new layer) using reference lines.
For instance sidewalks, Street curbs, Roof lines
Where they meet is the horizon

1d)flatten-> save as

1e)import to maya
I use 3ds Max so I generally use planes or set the image as my background

Now you can model making sure your scene camera (normally 35mm) matches the camera used in the shoot.

2) Particles and scripts
In 3ds Max I use Afterburn and/or FumeFX
If you haven't dealt with particles put on some coffee and give up sleep for a few weeks.

3) Masks in comp and a matte/shadow material in your scene.

[GFXIstic]

Hi,

you can make very cool explosions with the Maya internal fluids (only available in unlimited).
Check the sample files.

greetings

[TurboTronix]

Ya I used maya fluids (PITA for rookies like me). I can't get it to look as smooth as I want it and my PC is plain crap (can barely handle it).

I can't get the colors right, I can't figure out how to make the explosion go to one side rather then upwards or everywhere :|

I've been studying tutorials and my teacher has not touched fluids so all I got was "you're on your own".

Anyhow this is surely not a walk in the park!

[SoLiTuDe]

The Gnomon Dvds on maya fluids are top notch... if you have the extra cash.

[TurboTronix]

Yes Gnomon and DigitalTutors...

What about combustion? I heard of it but is it hard to use? Does it integrate with Maya?

[SoLiTuDe]

Combustion is pretty easy to use. I wouldn't suggest it for an explosion so much though. :) There are a few things I don't like about it, but all in all it's a great compositing app. I would say After Effects is a lot easier to use.

[TurboTronix]

Ok so after playing around with fluids and figuring out what I needed to do, here are several questions I got based on how to tackle my project:

1) I got no moving object in my scene

2) I got no moving cameras (stable on cam view)

Things to do:

Part 1: I have to create a fog effect (sort of like dry ice fog) from the bottom of the camera (cam is lying on the floor) and moving over some objects in the scene (pavement and a person lying on the ground)

Part 2: I have to create some debris flying from the top of the cam

Part 3: I have to create a thick smoke that will submerge the scene coming from all the sides of the cam (from behind the cam). After I got to make the title of the movie come out of the smoke and zoom towards the cam.

Questions:

For part 1: how to get the best effect for a dry ice that I can move over objects?

For part 2: should I use particles? I want debris with smoke coming out of it as it flies into the scene

For part 3: How to create the nicest looking thick smoke and then make it interact with the letters of the title (they will come out of the smoke and zoom into the cam)

Thanks for everyone's help! This project is a PITA but its very interesting and challenging as I've been discovering these past weeks :)

[olli20]

hey dude, some suggestions!



For part 1: how to get the best effect for a dry ice that I can move over objects?

if you want to have a thin and moving dust, i would prefer maya fluids. you can create a thin fluid and animate it via the internal texturing or push it around with some fields or the inbuilt dynamics. it depends on what exactly you want.




For part 2: should I use particles? I want debris with smoke coming out of it as it flies into the scene

if your debris consists of many small pieces, you can instance geometry to a particle object and emit it from the center of your explosion. with a proxy model of your source plate you can let these particles collide with the ground or what else is in your scene. when you have very big pieces in your debris i would suggest to simulate them as rigid bodys, or as an alternative, to keyframe them.
the smoke of small debris can be done by emitting smoke particles from the debris particles.for the big debris you can either emitt from the simulated debris itself.


For part 3: How to create the nicest looking thick smoke and then make it interact with the letters of the title (they will come out of the smoke and zoom into the cam)

in my opinion , in maya is the best way to create a thick smoke using fluids again. because fluids enable you to light the smoke in a realistic way, which cant`t be done very well with software cloud particles.after setting up your smoke you can make your letters (which i assume to be geometry??) collide with fluid . ithink a good way to do so is to use a motion field which can be found in the fluid menu.

hope this helps a little bit!

good luck

oli

[TurboTronix]

When you say "thin fluid" is that emmiting from an object? an emitter? How do I go about making it "thin"? What I got from fluids is that you got a container (2D or 3D) and an emitter of some kind from within...

I like the idea behind the debris concept, I'll get that going and see how it turns out!

The letters are geometry (prob some poly) so I'll try your advice and see how it goes....

Thank you!

Ron

[olli20]

hey,
you can use a fluid container with an emitter or without. for your purpose i would start with an 3d container with density and velocity set to dynamic grid. so you can use the opacity input graph, under the shading tab, set to maybe ygradient , to fill the container with density.with y gradient you can control the fog height.otherwise you can set it to constant to fill the whole container. then you can animate it with dynamics, or with texture time, texture origin etc. if you only want to move it with textures you can set all content methods to off.

oli

[TurboTronix]

I created a fog using only the container's settings. But now I tried adding an air field to mave it towards the objects without any success...How can I make the fog container move towards the objects? Should I key frame and translate the whole container towards the objects or is there a better way? What I want to do is make the fog sort of curl over objects as it collides with them...

[olli20]

maybe let the street emit some density und push it over the street with dynamics. so it can collide with the objects in the scene;)happy tweaking!

[Breed47]

Why not use ParticleIllusion? Just throw in some explosion emitters, adjust some settings (if needed) and render it. Renders almost in real time too.

Check this out: http://www.wondertouch.com

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