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 Cinema 4D, select File->Open, and from your /Scenes/FumeFX/ Tutorials folder, select the file Tut_01_start.c4d.


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 Plugins menu, select FumeFX submenu from the dropdown list, then click on FumeFX item.

From within the Front,Top and Right viewports, align FumeFX Grid with the candle’s geometry by using Move Tool (press e while FumeFX grid is selected). Open attribute manager for FumeFX grid and select General tab. Set grid dimension with Width, Length and Height attributes to roughly match the size of the simulation area at the top of the candle.



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.


Back within the Plugins/FumeFX menu, click Object Source item.



Move Object Source with Move Tool outside of the FumeFX grid in any viewport.


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


Open FumeFX Object Source attributes and drag Wick object from Object Manager into Objects attribute at Object Parameters tab. While doing drag'n'drop do not release mouse button after you click on Wick object until pointer is over Objects control in Attribute Manager. Otherwise Wick object will be selected as active and Object Source will be automatically removed from Attribute Manager.



Select the FumeFX Grid object again, then go to the Attribute Manager and open Objects/Sources tab.


Drag Object Source from Objects Manager into Object List attribute inside Attribute Manager.



Under the Object Parameters tab inside Object Source attributes, make sure the amount of Fuel is set to 100 and the amount of Temperature is set to 300.



Next, open on the General tab inside the FumeFX Grid attributes.


In the General Parameters group change the Spacing to 0.3. This allows you to control the amount of detail in the simulation.

Make sure that the Adaptive checkbox is active.

Under the Output group you need to set an output 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 date.


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 select the Simulation tab.



Under the Simulation group make sure that Quality is set to 5, Maximum Iterations is set to 200 and the Time Scale is set to 1.


Under the Smoke and Temperature group, change Smoke Buoyancy to 0 and Temperature Buoyancy to 2.


Under the Fuel group, change the Ignition Temperature to 100, Burn Rate to 40 and the Burn Rate Variation to 0.1.


Now let's select the Rendering tab.



Under the Fire group set the Intensity to 0.75.


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.


Left-click below the gradient control on area where gradient knots are placed. Try to match your Fire Gradient to the image below.



Once the Gradient is set, close that dialog and check to make sure the Opacity under Fire group is set to 2.0.


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


Now we are all set to run the simulation.


Choose the Start/Continue Simulation item under FumeFX menu.



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



While the simulation is running, you can enable the GPU Viewport Display to see how your candle flame will look. GPU Viewport Display Enable option is available under Viewport attribute tab in Attribute Manager while FumeFX grid is selected.


When the simulation ends, if you scrub your frame slider you'll notice that it doesn't appear anything has changed in your C4D scene. This is due to the fact that you haven't turned on the viewport preview of the simulation. Rest assured that the data is present, it just needs to be made viewable.


While FumeFX grid is selected, open Viewport tab in Attribute Manager.


Under the Channels group of controls, turn on the checkboxes for both the Fire and Smoke.


Scrub your frame slider again.



Now you can see both the fire and smoke voxel simulation solutions within the Cinema 4D viewports.


Next, turn the Smoke channel off from the Viewport tab.



You're left with only the Fire channel's solution displayed in the Cinema 4D 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.


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 you have enough room to let your simulations run naturally without hitting the boundaries of the volume.


Finally, make sure your Perspective viewport is active and render a frame.



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.