Fire Material

Open the Material Editor by pressing 'M' on the keyboard.

Select an unused orb. Once highlighted, click on the Sample Type in order to select the square shape. The square shape will make it easier to see what the fire will look like in the rendered scene.

Lower the Specular Level and Glossiness to '0.'

Open the Diffuse slot and click on the Standard button and choose Gradient. Your cube should look like as though there is a blend of black to white moving from top to bottom in the material editor's view port. However, the colors need to change.

Select each of the color slots from top to bottom, selecting Red, Orange, and Yellow. The Gradient Type should be Radial and the Noise amount can be raised to '1.0' with a size of '15'. The size number may change later and can be tweaked to better suite your scene. Choose Fractal as well.

Back out of this material and copy it to the Opacity slot.

Select the Opacity material and change the three colors to Black, Grey, and White. Once completed select the Gradient button (while still in the Opacity material) and change it to a Mask. Keep the old map as a sub-map.

Under the Mask option, select another Gradient. This time make the three colors black, white, black. You can add Noise (Fractal, amount of one, and size of 15), although you can feel free to play with the numbers to produce more refined qualities in the fire.

This completes the creation of the fire material. The next step will be applying it. Go back and proceed to Fire Animation.