Creating Fire Using the Combustion Apparatus

This lesson shows you how to create a realistic fire effect using the Combustion Apparatus. You also learn how to make the fire's glow appear on surrounding objects using projector lights. If you have been having difficulty creating a realistic fire effect, this lesson is for you.

Introduction

Realistic fire is extremely difficult to reproduce on a computer. Kinetix has created a really good solution with the Combustion Apparatus. This plug-in software was not included on the original Max disks. If you don't have it, you can download it from the Kinetix website. Not only can you make fire with it, but you can create good-looking explosions as well.

There are two parts to making combustion work. The first is to create the Combustion Apparatus, and the second is to apply the Combustion environment effect to it. You can find the Combustion Apparatus in the Create command panel under the Helpers drop-down list of object types. In the following tutorial, use the Hemisphere checkbox to create the apparatus, and only make very small changes to the Combustion Environment parameters.

This project involves creating fire by using the Combustion Apparatus, but it will also demonstrate how to make the flame's glow appear on the surrounding objects. Combustion does not emit light; you therefore have to be a little creative to display the fire glow on the surrounding objects. You can download the self-extracting executable file containing the (small) project file max58.max. This file is the basis for this tutorial, containing the finished project and its animation .avi. If you want to create your own objects, please do so. You will need surrounding objects to see the final effect.

Creating a Combustion Apparatus

You will find the Combustion Emitter button in the Helpers drop-down list.

1. From the Create command panel, click the Helpers icon.
2. Click the words "Standard Helpers" to open the drop-down list.
3. Choose Combustion Apparatus from the list.
4. Click the Emitter icon.
5. In the Top viewport, click and drag to create the combustion emitter object.
6. In the command panel, change the Radius to 50 and check the Hemisphere checkbox.
7. Move the apparatus to the center of the logs in the fireplace, as shown in the following image:

Rendering Combustion

Before you can see the fire and smoke caused by the Combustion Apparatus, you must assign an environment effect to the apparatus. You do this from the Rendering main menu, in the Environment dialog box. You must add combustion as an environment effect, but you must also use the Pick Object button and select the apparatus from the viewport.

1. From the Rendering main menu, choose the Environment option.
2. In the Environment dialog box, click the Add button to add an effect.
3. Choose Combustion from the list.
4. Move the bottom-half of the dialog up so you can see all of the Combustion parameters.
5. Click the Pick Object button, then place your cursor over the Combustion Apparatus and select it. After you have selected the Combustion Emitter, its name should appear in the list next to the Pick Object button.
6. Render the Camera viewport on frame 50 at 320 x 240 resolution.

Simulating Fire Effects

Professional animators will appreciate your animations because they know what went into the project. Non-animators may not be so forgiving, however. They are used to seeing world-class, film-quality animations in the movies. Those animations are often produced by teams that have access to state-of-the-art hardware and software. In most cases, you can make your renderings look better if you know which parts of your image need enhancing. For instance, the combustion system that you created in the previous steps does not emit light, so the fireplace looks quite dull without the glow from the fire. Your audience may not know what is missing, but they will appreciate you going the extra mile to add the effect.

The next section leads you through rendering the flame to an .avi file, then placing that .avi file into a projector light. If you use the combustion effect in the scene and render it to a file, you can render the scene so that the fire and the background flicker with the same timing. Note: Even if you hide the Combustion Apparatus, it will still render. If you need to keep it, but don't want it to render, open the Environment dialog box, choose the combustion effect, then uncheck the Active checkbox.

1. Hide everything except the combustion effect.
2. Create a Perspective viewport and zoom in close to the combustion effect.
3. Render the active time segment to an .avi file.

Creating a Projector Light

You could use the rendered flame animation as a material on the wall behind the fire, but it won't look as effective as projecting it through a light. You can cast shadows through the light, as well.

1. Select the light called Firelight.
2. Launch the Material Editor.
3. In the Modify command panel, click the Assign button in the Spotlight Parameters section.
4. Choose Bitmap as the type of material to project.
5. Click the Map: button in the command panel to open a dialog that represents the Sample Spheres in the Material Editor.
6. Choose the gray button where there is an unused material in the Material Editor.
7. Select the chosen Sample Sphere in the Material Editor.
8. Click the long, gray, blank bitmap file selector button and choose the .avi file that you rendered.

9. Unhide all objects and render a frame to see the effect.
10. Move the projector spotlight, if necessary, then render the entire animation.

Suggestions:

  • To enhance the animation even further, you could try copying the projector light to light the fireplace from behind. This will create a backlight effect on the edges of the fireplace that can look very good.

  • If you want to improve the shadow colors that the light projects, you could create a copy of the light and move it to one side, so that the shadows from the original light are filled in.

Project Files

File 1  File 2  File 3  File 4  File 5

 

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