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VTeixeira
11-16-2009, 04:46 PM
I'm trying to recreate something like this:
I've already posted the images in this thread, please take a look:
http://forums.cgsociety.org/attachment.php?attachmentid=148279
http://forums.cgsociety.org/attachment.php?attachmentid=148280

Cristian Hinz (arkangel-fx), told me to "emit from texture and animate a ramp for the ceiling to burn in certain direction."
I'm already trying that.
If anyone has a different approach please tell me.
Thanks a lot Cristian.

VTeixeira
11-20-2009, 01:52 PM
I've tried a couple of things but i quite don't understand how can I animate a ramp? Just like arkangel told me to.
Can someone help me here please?
Thanks

KidderD
11-20-2009, 02:47 PM
To animate a ramp, you animate the indices position attribute. So select the indices position right clk, set a key... repeat.

VTeixeira
11-20-2009, 03:03 PM
Do you think that for the type of effect I'm searching it will work?

stork
11-22-2009, 11:07 AM
depending on which version of maya you are running, a fluid container sim can nail these types of things pretty much spot on. The ramp texture is a good idea too, but it may be better served by creating that in a compositor or motion graphics package that has some 2.5/3d (mainly for speed reasons). www.videocopilot.net has some tutorials that when combined will give you the effect you want in after effects for example

VTeixeira
11-22-2009, 01:55 PM
I'll look into.
Thanks

VTeixeira
12-07-2009, 03:39 AM
I've tried to create some tests but I'm still with a lot of difficulties.
This is a link with the video of the effect I'm searching for:
http://www.fotosearch.com/FSE416/x10734271/
Hope someone can help.
Thanks for all comments.
Cheers

arkangel-fx
12-07-2009, 02:36 PM
Hey vic, can you post a playblast of what you have so far? I would like to know what you're at and maybe improve your aproach a bit.

tpalamar
12-07-2009, 05:58 PM
I worked on your ceiling fire a bit and came up with these results.




http://www.speffects.com/images/postings/ceilingFire1.jpg




To accomplish this, I used the presets from the house fire example in the book(Maya Studio Projects:Dynamics (http://www.speffects.com/index.php?id=book_maya_studio_dynamics)). I created a primitive plane and used it as an emitter. I changed the emissions to match those of the emitters in the house fire example as well. I then rotated the fluid container -90 degrees in the Z to use gravity and buoyancy to push the flame along the plane. I also resized the container to 2 10 10 and used 26 130 130 for the resolution. (You might be able to use less)



Density Buoyancy 5

Temperature Buoyancy 0

Velocity Swirl 20

Turbulence Frequency 10

The Transparency was set to .2

Dropoff Shape -X Gradient

Edge Dropoff 0.3

Temperature Input Bias -0.850

Opacity Graph 2nd Position 0.760


I think this is a pretty good start. It could definitely be improved by playing with some different opacity settings. Also the Turbulence Frequency and Swirl might be set to high for animation.

Skittixch
12-07-2009, 06:00 PM
Depending on your scene, you may be better served to work with geometry rather than fluid dynamic systems...I'm not sure how to pull this off in maya specifically, but here's how I'd do it in LW (the processes should be about the same, I'm just starting out in maya though..so I don't know the names of the tools you'd use)

make a plane with a high number of subdivisions (start with 100x100 and subdivide as necessary) then apply some noise (probably inverted crumple in LW) to that as a displacement map...then finally, using normal displacement, jitter all your polygons by a few inches over every frame to get a soft edge... If this step leaves you confused, check out this demonstration painting with polygons (http://vimeo.com/5660045)...it's for LW, but you can see the effect I'm talking about.

It's going to require some hand-editing as far as the motion goes, but you're guaranteed to get a solid look out of it, regardless of what the fluid dynamics want to do.

Seeing as this is a different approach from the ground up, I encourage you to try and follow through with your method...it's going to be more versatile if you can make it work...but keep this approach in mind as a fallback

tpalamar
12-08-2009, 02:17 PM
That ignition that goes through the ceiling.
How do I do that?


I am not sure what you are asking in terms of the animation. Are you having a problem with making the fluid move? In the ceiling example I did not add any key frames or use any textures.

tpalamar
12-08-2009, 03:16 PM
You can animate the plane going from outside of the fluid container to inside of the container. It will only start emitting in the container. Also turn wrapping on for the Boundary Y to keep the fire rolling through the container.

VTeixeira
12-08-2009, 03:18 PM
It's just like we see in this video:
http://www.fotosearch.com/FSE416/x10734271/
The flames are coming and growing in the direction of the camera.
Do you understand what I'm after?

tpalamar
12-08-2009, 03:28 PM
You also have two options if you stick with the plane. You can make it long enough to keep the flame moving for the entire length of the shot or time the animation with the flow of the fluid. So when the plane comes to a stop inside the container, the motion of the fluid takes over.

VTeixeira
12-08-2009, 04:19 PM
I see.
Two ways: increase the size of the plane and of the container or animate the plane going inside the container. Is it enough to animate only the plane going inside the container or I have to animate also when the emittion starts? The plane continues to be the emitter right?

Right?

tpalamar
12-08-2009, 05:56 PM
Yes, you only need to animate the plane. Here is an example. I animated the plane in a single axis heading towards the camera. No other key frames were set.


http://www.speffects.com/images/postings/ceilingFire.mov

VTeixeira
12-09-2009, 04:30 AM
Hello everyone,
I'm having some difficulties in increasing the detail of the fire.
I wanted the flame to go "down" a bit. I think it's behavior is the main problem. It looks a little flat you know. Is the emitter the problem?
Thanks for your time
IŽll post something soon.
I'm still working in this.
Thanks a lot for the example Todd

tpalamar
12-09-2009, 11:58 AM
The detail is influenced by the combination of numerous attributes but mainly influenced by the resolution, opacity, and incandescence. You could try reducing the Bouyancy and or gravity to get it to come down a little. This will also have an impact on its forward momentum.

On the emitter try increasing the Minimum and Maximum distance under the Basic Emitter attributes.

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