Tutorial 02: Plasma Vent

 

In this tutorial you will learn how to create simulations with fire. Moreover, you will control the opacity to make a flame transparent and you will also learn how to create a collision container. Finally, you'll see how you can tweak your settings visually after you've run your simulations and add post - process effects to the results.

 

In Maya, select File - >Open Scene, and from your [MAYA]/FumeFX/Tutorials folder, select the file Tut_02_start.ma.

 

After the file loads, create a FumeFX node so that it encompasses the entire Engine as is approximately 130 units high and 60 units width/length as shown below. Set FumeFX grid Spacing to 1.0.

 

 

Now, in the last tutorial, you created a FumeFX Object Source Proxy in the viewports and assigned the object from the scene so that it could be referenced in the FumeFX simulation. This time, we're going to do it the ???third way???.

 

Inside the viewport select fumeFX2 and pCone1 so that both of them are selected.

 

From the FumeFX menu, select Object Source option to create it. Inside Object source's attribute editor you will notice that pCone01 is already added to the list of objects.

 

Select FumeFX grid and from the open FumeFX' Relationship Manager. Notice that pCone01_source is already added. In the last step, with selected both FumeFX and cone all relationships were automatically resolved.

 

Now we only need to add the Case node as a collision object in FumeFX. We can do that by selecting the Case node and then FumeFX. With both selected, open the FumeFX menu, select ???Attach??? option and choose ???Attach Geometry To FumeFX Node As Collision???.

 

 

To edit parameters of a collision object, you'll need to open Outliner and select ???Case_collision???.

 

 

You will be presented with following parameters.

 

 

 

Since we are only worried about the inside of the jet case, make sure that the Type option is set to Solid.

 

Next, you'll set up some of the parameters for the simulation. Since this is a sci - fi plasma engine we do not want it to emit any smoke.

 

Select FumeFX and inside the Simulation rollout scroll down to the Smoke rollout.

 

Click on the Simulate Smoke checkbox to de - activate it. This will allow us to exclude smoke calculation from the simulation.

 

 

Next, within the Simulation - >General rollout, make sure that Advection Stride is set to 0.3.

To speed the plasma, set Time Scale to 2.0.

 

These settings will help make sure that the flames coming from the vent do not slow down too much as they move away from the source and dissipate.

 

Under the Temperature rollout, set the Temperature Buoyancy to 3.0.

 

Higher buoyancy will help plasma to rise faster.

 

Within the Simulation - >System rollout set the Vorticity spinner to 0.4 and set the X Turbulence spinner to 0.30. This will give the plasma flames some subtle waves and natural motion. Under the Turbulence Noise rollout, set Scale to 10.

 

After this, go to the Fuel rollout and set the Ignition Temperature to 0, Burn Rate to 35, Burn Rate Variation to 0.2 and Expansion to 1.5.

 

These settings work in concert to determine how fast and hot the fuel will burn and how much pressure it puts on the simulation volume.

 

Next, select the Output rollout and set an Default Path. If you followed our suggestion from the first tutorial, simply create a new folder called Tut02 under the FFXSimData folder and use it for the jet engine simulation data.

 

In the General Parameters rollout, make sure that Spacing is set to 1.0. We don't want super detailed plasma flames and this setting will also help keep reasonable simulation times.

 

Now, select the Rendering Settings rollout and scroll down to the Fire rollout.

 

Within the Fire rollout, set the Intensity value to 3.0 and the Opacity value to 1.0.

 

Open the color gradient located inside the Fire Color Tab.

 

Try to match your Fire Gradient to look like the example below. What you're going for is a dark gray - blue with a small slice of light gray - blue at the center of the flames. Our plasma is going to have a blue tint to it to start. To understand the gradient, try to remember that the left - most edge represents the edges of the flames, while the right - most edge represents the core of the flames. So in this case, we want the flames dark on their outer edges and more solid towards their centers.

 

 

Next, you will to need change the Opacity curve of the fire.

 

Open the Fire Opacity Tab and open the ramp. Delete one of the keys in the middle and move remaining keys to match the position of the curve shown below. Change Interpolation to Spline for all three keys.

 

 

When done, close the Fire ramp dialog.

 

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).

 

Before you start your simulation, let's open the Preview Window by clicking on its button in the FumeFX Attribute Editor.

 

Next, click the Start Simulation button.

 

When it's done, go to FumeFX Rendering Settings - >General Parameters rollout, enable Use Maya Volume Sampling and set Maya Volume Samples to 100. Select mental ray renderer for rendering and render frame 30.