Fume Fx Properties
Written by Panait Mihai
Thursday, 19 June 2008
The FumeFX UI Floater Window is your main command center for creating and controlling effects with FumeFX plug-in. It is a modeless, floating dialog box that contains a wide range of controls, which are logically organized into a toolbar and five tabbed panels. To access this window: select a FumeFX object in your scene; click on the 3ds Max Modify icon; and then, select the FumeFX UI button to toggle it open.
I’ve done some tests on the most important properties to see how each affect the look of the fire. This tests are intended to save you some render time by reducing the number of tries, if you have a clear image in your mind about how your fire should look like. You can download the animated version from the link at end of this article.
Spacing (General Parameters Rollout) – This parameter directly affects the detail level in your simulation. Type in or use the spinner to set the spacing of the voxel-based grid. The chosen value defines voxel size; smaller voxel size allows for more voxels in simulation, which produces greater detail.
Quality (Simulation Rollout) – This defines simulation realism. Higher quality increases realism, but means more computation and slower simulation performance. This is sometimes necessary; for example, it is advisable to increase quality for fast moving objects. Another way to look at Quality is that this number represents how many times the the Maximum Iterations will be used to determine the simulation.
Advection Stride (Simulation Rollout) – The lower this stride is, the less dissipation of velocity and smoke will happen. It is a more or less inverse proportion to simulation time.
Time Scale (Simulation Rollout) – Use this to speed up or slow down the passage of time during simulation. If you set it to 0, the simulation comes to a halt; set a higher value to increase speed. If you accelerate time by some significant amount (>1.5x), you will have to increase the simulation steps as well to preserve stability and continuity. Also, note that you can animate this parameter.
Gravity (Simulation Rollout) – This value defines gravity strength. Note that this affects smoke, based on the smoke’s density value.
Buoyancy (Simulation Rollout) – This value defines how much the fluids will rise in correspondence with the temperature.
Vorticity (Simulation Rollout) – This parameter is very useful for coarse grids, where simulations lack detail. When you increase grid detail then the need for vorticity is lowered, since the simulation itself will result in more detail. Higher vorticity will increase the number and strength of small vortices in the fluid.
Velocity Damping (Simulation Rollout) – This gradually slows down the speed of flow, simulating internal friction.
Burn Rate (Fuel Rollout) – The percentage of fuel in each voxel that is burned with each frame. Heat production and Expansion depend on the amount of burned fuel.
Heat production (Fuel Rollout) – This determines the rate of temperature increase per burned fuel. With high heat production, temperature in the grid will increase, causing fluid to rise faster (due to the buoyancy parameter).
Expansion (Fuel Rollout) – This determines the rate of pressure increase per burned fuel. Excessive expansion can create extreme velocities and cause simulation times to increase significantly.
Dissipation Strength (Smoke Rollout) – The higher this value, the more rapidly smoke will diminish. This parameter is expressed as percentage of voxel value that will be lost.
Fuel Amount (Object Source Parameters Rollout) – This is the fuel amount that is set or added to each voxel.
Temperature Amount (Object Source Parameters Rollout) – This is the temperature amount that is set or added to each voxel.
Smoke Amount (Object Source Parameters Rollout) – This is the smoke amount that is set or added to each voxel.
You can also download the animated version of this gruped by categories in a Flash projector file. (exe file – windows only)