Particle FX
Some people have asked me how I made the particle effects in Bagel 2, such as smoke and fire. Well, I’m sure you’ll be glad to hear that most of them were accomplished relatively easily using an application called Particle Illusion SE and a compositing program. I received Particle Illusion SE for free with a magazine, and I must say it’s a great time saver for working with 2D particles.
The way I did it was simple: I’d choose a preset from the library which more or less fit my requirements for a specific shot. Then I’d play with the various settings until it looked and behaved just the way I needed it to.
In After Effects, I often like to stack the same particle sequence in several layers with different blend modes, which gives an added level of control.
In the scene below, most of the smoke was done using Particle Illusion. To create the smoke trail following Bagel, I animated the position of the smoke particle’s source, which I found worked surprisingly well.
The shimmering light coming from Bagel’s camera wasn’t done in Particle Illusion, however: This is a true volumetric light rendered in 3D and composited later with the rest of the scene. Most of the haze and fog is done using a pretty cheap trick: A simple fractal cloud layer in After Effects, with the blend mode set to “Add”…
Post Processing
I’ve heard lots of nice comments on the look and atmosphere in Bagel 2. Good that nobody’s seen the images that came directly from the renderer — they looked bland, flat and lacked much of the appeal they have now. Thank god for post-processing!
Straight from the renderer
After post FX
Compare these two images: The left one is “untouched”, in that it is exactly what Maya produced when hitting the “Render”-button. The image on the right was post-processed in After Effects to add an effect of fog and depth of field to the background, blurred highlights for that dreamy feeling and some quite intensive colour correction .
To achieve the haze and blur in the background, I had the renderer output a so called depth-map or z-map. This is a grayscale image of the scene, where the lightest parts are closest to the camera and the darkest are the farthest away. This map can be used by a post-processing application to mask certain effects.
Depth pass with Bagel in the crater
Many compositing applications include plug-ins for use with depth maps, but the trouble is that there are several different formats of depth maps so it’s quite likely that you’ll have to use a workaround like the one described below.
For the haze I used a “Solid Layer” with the colour of the fog and applied the inverted depth map as a mask. Then I played with the opacity and the blend modes until I was happy with the look — I found that an opacity value of 50 – 75% coupled with the blend mode “Lighten” will give convincing results in most scenes. Though you’ll need to fiddle around with the blend mode as results vary heavily depending on the scene.
Due to the depth mask, the fog gets thicker in the distance — there are many more effects you can achieve using this method!
The depth of field effect is achieved in roughly the same manner, but this time by using an “Adjustment Layer” instead of the “Solid Layer” and applying a blur filter. This one is a little more work to get to look right, but I think you get the idea.
Well then, I hope I was able to give you a little insight into the making of my animated short film Bagel 2. The film is available on 3dtotal’s “Short Drawer DVD” or viewable online in the shorts section of this site — I’d be pleased if you had a look!
(originally published on Vocanson)
