so.
the fireball…
i did some renderings, to show how it could look like.
i used gravity and a volumeAxis-field plus a turbulence field
to drive the motion of the Particles.
here is a blue version
www.zipl.de/fireball/blue.avi
and a red fire like one
www.zipl.de/fireball/redFire3.avi
how it`s done:
created a NurbsSphere and scale it up a bit to 3 or smth near by
then go to
particles -->emit from object
now select the emitter in the outliner and open the attribute editor.
set the emitter rate to 500 and make “scale by object size” selected
to see enough particles to work with.
next go to Distance/direction and set min Distance to 0.1 and max Dist to 0.3.
we need this for the collision with the sphere later.
set the speed to something slow like .2 or .3 and a little bit of randomness.
now select the particles in the outliner or play a few frames to select them
with the mouse.
under Lifespan Attributes set the particles to Random with a lifespan of 0.666 with a
Random Value of 0.2.
now go to
Fields --> gravity
at this point the particles falling down but this doesnt matter cuz we will change it.
in the attributes of the Gravity field we have a direction attribut for Y which
is set to -1. change it to 1 and lower the magnitude a little bit to smth around 5.
now the particles raising in the air.
to get a more spherish look, i created a Volume axis field with its center right
above the sphere and made the sphere a collision object for the particles.
for the collision select the particles then the sphere and go to
particles --> make collide
cuz we set the min/max attribute the particles now hit the sphere and move along
when they are pushed inwards wat we want to do now.
go to
fields --> volumeAxis
open the attributes and go to volume Control… change volume shape to sphere and scale
it up in Y to get an oval look.
move it up so the center is right above the partcle sphere. and scale the volume field
in X and Z so that the particle emitting sphere is in the bottom of the volume axis field.
make the following changes.
set the magnitude to 35 and attenuation to 0 u can keyframe that later to change the top
burst shape.
in the volume speed section change “away from center” to a low negative Value.
and ad a llill bit of turbulence.
now the particles move inward to the center of the volumeAxisField wich was slightly
above our nurbsSphere.
now comes the tricky part
open flash and set the stage to 256x128 thats enough.
create 3 layers and paint on each layer on the bottom of the stage with a
black stroke like on this pictures.

now create a second keyframe on each layer at frame 20 and paint the strokes abit
greater.

tween between the frames and export the animation to a Gif-Sequenz with 4 colors
to the sourceImages folder in Your MayaProject-Directory.
so the seqence looks black parts growing bigger like shown below

go back to maya and select the emitter, open up the texture emission attributes and check
“Enable Texture Rate” and “emit from dark”. Now hit this checkerButton and select file
from the renderNode selection popping up.
Now go to the sourceImages Folder and select the first image of the gif seqence.
hit “use image Sequence”. cause the image seqence is named with *.0001 we have to made
some changes to the frame offset and the image numbers.
right click on image number and create Expression or edit… i dont know rigth now…
u will see.
we want to have the raising of the flame starting a little bit later so we must insert an condition
if (frame< 35)
{
file1.frameExtension = “0001”; // this sets the image number to 0001 so that it uses
Picture.0001 while the frame is lower 35
}
else if ( frame>=35 && frame<55)
{
file1.frameExtension = (“00”+frame); // this adds to zeros to the frame so our numbered
where found cause maya searches for the file the name
plus the frame extension wich comes without
the zeros. cuz of this fact we have to change
the FrameOffset too, so maya dont searches for a pic
called picture.0035 at this frame and so on.
file1.frameOffset = -35;
}
else if (frame>=55)
{
file.frameExtension = “0020” //this must be the last Picture of your imageSequence
}
the last condition tells maya that it should use the last image of our sequence while the rest of the timeline
is playing.
if U want to see what is happening with this seqence u must add a lambert shader to the Sphere and drag the file
node to the color channel now with hardware Texturing on u can see how the image moves.
thats it for raise up the flames. now we must add color, opacity and
change the render attributes so it looks like flames.
go to particle Attributes and click on color, check per-Particle and hit ok. the same for opacity.
now right Click on rgbPP and create a Ramp with fire like Color from bottom Yellow over red to top black.
at opacity you click right,create ramp, go to edit ramp and delete the middle color and strip down the
Black a little bit to a position of 0.7 or 0.8.
in the render Attributes section u now set to multiStreaks - lower the radius a little and higher the count
set a small negative tailfade and a tailsize around -2 so the multistreaks are smaller at the top.
thats it for the setting… if u now play u will see smth similar to my.
to get thicker flames u can higher the emission rate and play a little bit with it or key frame it, to get
some motion in ur flames.
in the hardware render buffer u have now to set lineSmoothing on, and check multiPass, set the
multiPasses to 16 or above and the motion Blur to what ever u want. render out in the HWB and enjoiii.
i hope i dont forgot somthing. if anything is unclear ask.
and here are some pictures of my settings.
www.zipl.de/fireball/emitterSettings.jpg
www.zipl.de/fireball/particleSettings1.jpg
www.zipl.de/fireball/gravitySettings.jpg
www.zipl.de/fireball/vaxisField.jpg
www.zipl.de/fireball/vaxisField_settings.jpg
www.zipl.de/fireball/textureEmitt.jpg
www.zipl.de/fireball/sourceImages.jpg
www.zipl.de/fireball/particleRenderSettings.jpg
www.zipl.de/fireball/particleColorRamp.jpg
www.zipl.de/fireball/HWBSettings.jpg
if u have any suggestions or questions, i am very open for everything
that helps improving Maya abilities. thanx
-heavy-
edit: ohhuu i was to late …8(
nevertheless i hope this helps somebody. )
cheerz.