Simple Fire

Fire made Simple

	Step 1. Start with a bunch of 3D animated balls. Its OK if they pass through each other. In this example the balls are born low in the scene at random X and Z positions then move up in Y.
Step 2. Put a fractal texture on the balls. Use a spherical UV space around the area in the scene or better yet a 3D volumetric texture. Lighting needs to be flat or diffuse only with the light at the camera.
	Step 3. 2D distort using a blurred version of the white to black image in the ball render of step 2.
Step 4. Remap the black to white to reds, yellows. (or the fire colors of your choice; blue for natural gas; yellows for wood; orange and dark reds like this one for oil fires)
	Step 5. Add an overall glow. In this case, the image from step 4 was box blurred then added on top of the origanal step 5 image.

After the movie Antz completed production I decided to move over to PDI CAFE (Commercial Animation and Film Effects). This was great for me since I was able to work on a bigger variety of production issues.

While in CAFE I was with a group of animators asked to test a new renderer by lighting a simple still life. The shot was of an orange dropped onto a plate with other fruit. In my test the orange burst into flame.

The video of my antics made the rounds at PDI and on its way through the Shrek effects department caught the eye of the effect artists creating the small flame for the torches.

Small sidebar: the big fireballs in Shrek were created using a program called "Flu", created by Nick Foster. The Flu system is ultra cool and got Nick an Academy Award, but at the time the torch flames were too much of a runup to be handled by Flu.

To make a long story short, my one page (50 line) script that used a very quick and simple 3D render, then a 2D comp with a distort, remap and glow, worked just fine for the occasion.