Tutorial 01: Candle Flame


In this introductory tutorial you will learn how to use FumeFX at a basic level. It will also introduce you to the FumeFX UI.


In Maya, select File - >Open Scene, and from your [MAYA]/FumeFX/Tutorials folder, select the file Tut_01_start.ma.


This scene is nothing more than simple candle geometry. We're going to add the flame to the wick.


After the file loads, go to the FumeFX menu and select FumeFX Node from the dropdown list.

Set FumeFX size to Width=14, Length=13, Height=35. Then in any viewport, move the FumeFX Grid gizmo into position at the top of the candle geometry.



NOTE: Make the FumeFX grid only as large as the simulation area you need. This will affect your simulation times in a big way.


Now that you have a FumeFX Grid in place, you need to create a Source to help drive the simulation.


For this purpose we will need an Object Source. It can use any geometry in the scene as the source. There are three ways to "tell" Object Source which geometry to use.


Create Object Source from the FumeFX menu without anything selected in the scene. Set its Icon Size to 5. You will notice that inside the attribute editor there is no geometry selected (as seen on the image below).


To add geometry, you'll need to select wick object in the viewport and then hold [SHIFT] key  and select ffobjectSourceProxy1 and in Object Source's attribute editor click "Attach selected".


Other way to connect geomery to Object Source is to select wick object in the scene and then create Object Source from the FumeFX menu. This will create Object Source node with the wick object added automatically.



Since the FumeFX Object Source simply informs the FumeFX simulation engine of an object you want as part of the simulation, its icon doesn't need to reside within the FumeFX Grid volume.


Select fumeFXShape1 node in the scene. Inside the Attribute Editor click on the FumeFX Relationship Manager button and selecte the ffxObjectSource1.



This will "tell" FumeFX to use ffxObjectSource1 for the simulation.




The fastest way to perform node creations and additions is to select the wick geometry and fumeFXShape1 node and then create Object Source by clicking on the Object Source menu option (or Create Object Source icon from the FumeFX shelf). This method would have created new Object Source, add Object Source to selected FumeFX and also add selected geometry to the newly create Object Source.


Select Object Source and make sure the Fuel value is set to 100 and the Temperature value is set to 300. Those are actually default values for the Object Source.

Go back to FumeFX node and under General Parameters set the Spacing to 0.15. This parameter allows you to control the amount of detail in the simulation.

Make sure that the Adaptive checkbox is active as adaptive grid simulates much faster than the non - adaptive one.


Under the Output rollout you need to set a Default Path to store the simulation data. Click on the ellipsis (...) button next to the path and then create and set a new folder location on your hard disk to store the data


A good option would be to put your simulation data into individual folders. Something on the order of creating a main folder FumeFXSimData, and then creating new sub - folders for your different sims. You can create a new sub - folder for this one called FFXTut01.


Now let's move on and scroll down to the Simulation rollout.

Under the Simulation - >General rollout make sure that Quality is set to 5, Maximum Iterations is set to 100 and the Time Scale is set to 1.


Under the Fuel rollout, set the Ignition Temperature to 100, Burn Rate to 50 and the Burn Rate Variation to 0.3.


Under the Smoke rollout set Smoke Buoyancy to 0.


Under Temperature rollout set Temperature Buoyancy to 2.


Select the Rendering Settings rollout.

Under the Fire rollout set the Intensity spinner to 1.25 and Opacity to 1.1.


Next, we want to build a gradient for the fire color. Since a candle's flame goes from orange to yellow to blue to black (transparent), that's our goal.


Open the Fire Color Tab. Try to match your Fire Gradient to the image below.



Under the Smoke rollout change the Ambient Color to a dark Gray (RGB, 0 - 255: 30, 30, 30) and the Opacity to 1.


In Maya, set the "End time of the playback range" to 100 and in FumeFX set End Frame to 100 (Output rollout) and Play To to 100 (Playback rollout).


Now we are all set to run the simulation.


Choose the start Simulation button from the top of the FumeFX Attribute Editor.



At this point, the simulation begins and you will see a progress dialog pop up.



While the simulation is running, you can click on the Preview Window icon to see how your candle flame will look.



When the simulation ends, if you scrub your frame slider you'll notice that fire and smoke appear in your Maya viewport. This is due to the fact that those channels are selected by default. You can enable or disable viewport channels under the Viewport - >Display Components rollout.



Now you can see both the fire and smoke voxel simulation solutions within the Maya viewports.


Next, turn the Show Smoke off from the Display Components rollout.



You're left with only the Fire channel's solution displayed in the Maya viewports. What's more, is that you should be able to see the color gradient you set earlier displayed in the voxel viewport representation. This can be a very handy way to see how the various aspects of your simulation are reacting. What's more, it means if you want to tweak the coloration, you can do so now and see how it affects your calculated simulation without having to re - run it.


To get a bit thicker flame you'll need to change the Expansion parameter to 3.0. This parameter is located under the Fuel rollout and run the simulation again to see the difference.


Also, depending on how much height you gave your FumeFX Grid, you will most likely see the smoke hitting the top part of the volume and disappearing. Keep the boundary edges in mind when setting up your scenes. Depending on what effect you're after, you'll want to make sure that you have enough room to let simulation run naturally without smoke or fire hitting the boundaries of the volume.


Under the mental ray Render Options disable the Enable Default Light option.

Enable Final Gathering option located under the Indirect Lighting tab.

Under the fumeFXShape1 Rendering/General Parameters, enable Use Maya Volume Sampling option. Under the Fire rollout, increase the GI Multiplier to 4.0.

Scroll down to Illumination/Multiple Scattering rollout. Enable Multiple Scattering checkbox and increase Fire Strength to 5.0.


Finally, make sure your Perspective viewport is active and render a frame by using mental ray renderer.



On your own, you should render out the entire animation to see how the flame behaves. Also, experiment with the Smoke Buoyancy and Temperature Buoyancy spinners. You can change those values while the simulation is running and see how these instantly affect the movement and height of the flame and surrounding smoke.


While fairly simple, this first tutorial should have given you some ideas of the potential and power within FumeFX. We're not done yet - there's still more to come.