Playing with lights...

I've been spending some time recently experimenting with lights and textures and came up with a quick way to make light effects. One of them is an animated candle light, but I've also found it works for torches, afterburners, landing lights and adding some variations to starfields. Here's what a finished example looks like.

The animated candle light mat...

The first step is to set up the scene to get the animated mat, so set your background to color and make it black. Next add a primitive cylinder in your scene. For the material, set it to black, and use the default phong reflectance. Set the phong for no Luminance or Diffusion and max out Shine. You'll set the specularity for how you want the flame to fan out, and how soft you want the edge of your flame to appear. For the specular color I've used a light blue.

Next, add a spotlight to your scene aiming 90 degrees facing the cylinder. Start with the spotlight directly in the center of the cylinder width. This spot will be the base of the flame, so color it a flame blue. Adjust the brightness up to taste. Now copy the first spot, and move it lengthwise on the cylinder, as this will become the flame tip. Coloring the tip is just a littler color foolery. If you just color it yellow, you get green because the specular color is blue, but if you color it with blue's contrasting color of orange, aiming more at yellow than red, you'll get yellow.

setting for the base light setting for the tip light

Now for forming the flame, the angle of the view (or camera) to the cylinder sets up the bottom and top edges of the flame. If the 'flame top' end of the cylinder is aiming more away from you, the bottom will get a straighter line, (afterburners, torches), if it's more centered the edge is more rounded. For the candlelight I use only a little rotation so the ends don't wind up looking the same. Also, expanding one end of the cylinder helps spread out the base of the flame. Here's what my final rig wound up looking like.

The animating is really simple. Select the tip spot, set the frame to 5. Move the spot higher, and scale it smaller. Set your next frame number, and move and scale it again. The example uses just simple equally timed moves, but realistically, it should shorten the duration of the downward movement. Also moving the base spot wouldn't hurt. (Even better, if you're a scripting type person, making 5 or 6 random sequences.) You can change the appearence of the flame by moving the spots off of center as well. Finally, you do the render to file thing. For your alpha mask setup, just remove the colors from the lights and materials at frame zero, and render again.

A few other notes...

As I've mentioned you can use this rig for working a number of different effects using a multiple number of lights. Using a sphere and changing the specular color, you can make a number of rounded light effects, (stars, landing lights, etc.). Letters beveled and lit up can make a quick neon sign, or just interesting artistic text. All you need to do is provide the beveled surface for the specularity. I've also found a projector light useful for adding shadowing effects into the specular areas. Have some fun with it!