a) Fluid Effects>Create 3D Container
b) Create>NURBS Primitives>Torus
c) select both, Fluid Effects>Add/Edit Contents>Emit From Object
d) put the torus inside the box, never scale the box - just the torus

a) open the fluidShape Attribute Editor(fluid attrEd)
b) apply the following settings

Container Properties
--Resolution - 20x20x20
--Size - 2x2x2
--Boundary X - none
--Boundary Y - -Y side
--Boundary Z - none

--The Boundary attributes are kind of confusing at first. None means that the fluid can pass through the edge of the fluid container(the box). This does not mean it will render outside the box. Fluids can only exist within a fluid container. Absolutely. No way around it. If you are doing a flaming torch, and the torch moves, the container will have to as well. Also worth noting, the fire in the container will not react to this movement as it would in real life. You'd have to use a motion field to simulate the air resistance. Having a boundary means that the edge of the box will act like a wall, forcing the fluid to curl back into the box, and if all of the boundaries are on the box will fill up.

Contents Method
--Temperature - Dynamic Grid
--Fuel - Dynamic Grid

Dynamic Simulation
--Simulation Rate Scale - 2.5

Contents Details

Density
--Density Scale - 1
--Bouyancy - 5.771
--Dissipation - .058
--Diffusion - .003

Velocity
--Swirl - 12

Turbulence
--Strength - .041

Temperature
--Temperature Scale - 2.0
--Bouyancy - 7.024

Fuel
--Fuel Scale - 1.967
--Reaction Speed - .967

Shading
--Transparency - .587 (value)
--Edge Dropoff - .752

Color
--Selected Color -

H 0
S 0
V 0

--We don't need the color attribute, because we'll be using incandescence to color our fire. Honestly can't tell you why, that's just how they did it in the turbulentFlame example.

Incandescence

--You'll need to adjust the ramp with the following inputs:

--Selected Position - 0
--Interpolation - Smooth
--Selected Color -

H 26.79
S .901
V 22.5

--Selected Position - .736
--Interpolation - Smooth
--Selected Color -

H 17.06
S .873
V 20

--Selected Position - .964
--Interpolation - Smooth
--Selected Color -

H 17.06
S .873
V 0

 

--Input Bias - .387

Opacity

--This is sort of like a ramp, only different. It's pretty simple, just click to create a new dot and drag to move it. If you need to remove one, click on the x box below it.

--Selected Position - .121
--Selected Value - 0

--Selected Position - .171
--Selected Value - .780

--Selected Position - .257
--Selected Value - .420

--Selected Position - .357
--Selected Value - .220

--Selected Position - .543
--Selected Value - 0

--Input Bias - .279


Shading Quality
--Quality - 3
--Render Interpolator - Smooth

Lighting

--If you add lighting you'll need to check Real Lights, but it increases render times. Self Shadowing will improve the 3D-ishness of the fire, making it look like it has depth, but will also increase render times. If you've really got a lot of time on your hands, turn on Real Lights and then use raytraced shadows - it looks really cool (although I have never seen a fire that cast actual shadows).

--Uncheck Real Lights

c) switch to the fluidEmitter tab
d ) apply the following settings

Fluid Attributes
--Heat/Voxel/Sec - 2
--Fuel/Voxel/Sec - 4
Fluid Emission Turbulence
--Turbulence - 6

a) open the render globals, and set the render quality to Production Quality

--Later, you may want to change this for test renders but with only one emitter we might as well have quality renders while we can.

b) make sure you are on the first frame by hitting rewind
c) play till about frame 45, hit stop, and render the frame