For animation director Vida Vega, nothing quite compares to the tactile marks and texture you get with physical materials. “I’m always looking for ways to use digital techniques sensitively alongside more ‘traditional’ drawings to get the best of both worlds in my work,” she enthuses.
In this tutorial, Vida shows you a way of using particles that looks convincing as part of a hand-drawn world, while giving you a lot more control and flexibility over the animation than paper alone.
Vida has used particles to bring the snow in her drawing to life, but the techniques detailed here can equally be used for rain or dust, or other elements that would be laborious to animate by hand and a pain to edit.
You’ll also learn an approach to building animated scenes drawn from the traditional practices of hand-rendered cel animation, but updated for modern software like After Effects.
Time to complete
Animation, 2 hours
Photoshop, After Effects
First, work out the composition of the image you want to animate. I usually draw all the elements separately – in this case, the lamp post, penguin, snow and background – so I can test how well they will work together visually when they are later animated on separate layers.
Scan the elements, open them in Photoshop and start layering them together – colour correcting each one to remove any paper texture. Because my drawings are dark graphite on paper, most could be layered over the softer pastel background with a Multiply blending mode, without having to cut them out.
For those elements you want to ‘glow’ – such as snow and light on the lamp post – simply invert them and use a Screen blending mode. Paint mattes and highlights for areas you want to stand out from the background – here the shine on the lamp post and the penguin’s belly – and save these as PNGs with transparency.
I created this ‘boil’ animation for a snowflake by drawing three frames on paper. I used two different boils for the snowflakes, so there would be some natural variety and to break up the repetition when seeing lots of them together.
Once these are drawn, scan and save them in a separate folder for each ‘boil’, naming the files sequentially. Open each in Photoshop and invert them (Cmd/Ctrl + I), so they become white on black, then save each.
Now open up After Effects and make a new composition. Because the drawing I chose to animate is portrait, I’m going to put in a camera move to pan down from the lamp post to the penguin.
To do this, in the composition settings (Cmd/Ctrl + K) I resized the comp to be the same size as the image. This is just like old-fashioned animation layouts – a really big drawing you would move underneath the camera to provide enough world for your action to move around on. It doesn’t matter that this comp is such a crazy size, the final comp will have a standard widescreen aspect ratio.
Next, import all the elements. All the boils should be imported as image sequences, while the mattes and background should be individual images. For each image sequence, select ‘Interpret Footage’ and change the frame rate to 12fps. Set the sequences to loop, as that will be more than long enough for this clip – I’ve looped 200 times.
Once you have your footage, layer everything up apart from the snow (we’ll be using AE’s particle engine for this) using the same blending modes as in the Photoshop composition.
Particles are great because they allow you to generate a whole snow storm from just a couple of boils, as opposed to animating the whole thing by hand on paper. Make a new composition for the snow – I made mine a standard widescreen size, as it only needs to be big enough to contain the snow element rather than a camera move. Make sure it’s 12fps to match the rest of the animation.
Create a solid and apply the CC Particle World effect (Effect > Simulation > CC Particle World). As we intend to use the boils we have animated for the snowflakes as textures, add them to the composition.
Open up the CC Particle World effect in the Effect Controls panel and find the Particle > Particle Type heading. We want to use a particle type that will allow us to use the boil we animated as a texture, so choose Textured Square from the drop-down menu. Go to Particle > Texture > Texture Layer and select one of the snowflake image sequences we added to the comp.
The snowflake boils we imported are white on black, but have no transparency. As we want the snowflakes to be able to overlap and intermingle as they animate, select Screen from the Particle > Transfer Mode drop-down menu.
We’re now ready to change the way the particle effect emits the snow. In the Effect Controls > Physics > Animation drop-down menu, try out a few options. I settled on Twirly as it gave the best billowy, snow-like particle movement.
Move the position of this particle emitter (Producer > Position X, Y, Z) high out of frame, so the particles fall for a moment before entering; and increase the Longevity, so the particles don’t disappear. Tweak the Birth Rate to adjust the amount of particles in the scene.
Now we can refine the behaviour of the particles. There are lots of parameters in the Physics section, I found it took a bit of trial and error to find a combination that worked for me. These are the attributes I settled on – Velocity: 6.97, Gravity: 0.290, Resistance: 0.9, Extra : 1.33, Extra Angle: 0x-249.0, Gravity Vector>Gravity X: 0.320, and Gravity Y: 1.000.
Once you’ve got the particles moving to your satisfaction, bring in the second boil to break up the pattern of the snow. This extra sense of randomisation will help tone down the digital feel of the animation and make it less jarring when brought together with the other elements.
Duplicate the solid you have been working on, and in the Particle Effects settings change the texture to the second boil added to the composition. Tweak the values of the particle effect to differentiate it further.
Go back into the oversized composition containing the other animated elements and add the particle composition to the timeline. As I want the snow to cluster around the lamp post, I created a feathered circular mask around the light, over the particle layer.
Now all the animated elements are in place, we need to create the final comp from which we’ll render the clip, and in which we’ll animate the camera move. Create a new composition with the oversized animation comp inside it and keyframe the Position to animate the camera pan.
As a finishing touch, I animated a boil for a 16:9 box, which I placed over the top of the composition with a Screen blending mode. This gives the final animation a soft vignette that matches the effect of the original drawing.