Paint magic

After reviewing over 250 graphics and design applications for PC Pro, I like to think I know what’s out there, but I recently received an email asking me to take a look at three applications I’d never heard of called PD Particles, PD Artist and PD Pro. Their bargain-basement prices set my expectations low and the host website www.thebest3d.com – partly devoted to a novel about squirrels – lowered them further, but within seconds of opening PD Particles my eyes were wide open and my jaw dropped…

The PD Particles interface could hardly be simpler: just five palettes and one creative tool, the Brush. Just two commands are available on the button bar below the menus, to make your brush pressure-sensitive (if you’re using a tablet) and a drop-down menu of presets. Select the first preset, WinterBranches, start to paint and the result is extraordinary – a dead tree, complete with branches and sub-branches, springs to, er, life under your brush. Other preset brushes let you add various kinds of grass, tree, bush, weed, fern, sponge, coral, hair and more, plus numerous more abstract patterns – and all with single brushstrokes. It’s a joy to explore.

But how does PD Particles create such amazing effects, since the only input you’re providing is the path and speed of the brush? The answer offers an insight into the way all computer-based brushes work; namely, by laying down a sequence of circular dabs along the path you traverse – pack them close enough and all you’ll see is a smooth line, drag faster and you see individual dabs open up. What PD Particles does is treat this path and speed information as just a starting point, splitting off new paths at various angles with various lifespans, and affected by parameters such as gravity, velocity and drag. And these new paths can themselves spawn new paths. Open up the Particles palette and you can fine-tune all the parameters to produce subtle or radical variations in seconds.

The most important parameter is colour, particularly the ability to vary it along each path and subpath using gradients: each preset comes with a range of eight gradients, which subtly or dramatically change the end effect. You can quickly mix in black or the current foreground colour using the Particles palette’s Shading and Tint options. Alternatively, using the dedicated Gradient palette, you can edit the gradient as a whole. This again reveals PD Particles’ outside-the-box thinking – where most applications have you laboriously set colour stops, here you simply drag swatches onto the ruler, or drag the red, green and blue component curves to directly and interactively change the gradient as a whole. Even more impressive, the Opacity tab lets you quickly create semi-transparent effects to produce realistic fur or create breaks in the stroke.

The creative potential of these particle-based strokes is extraordinary, from convincing vegetation for 3D applications through abstract backgrounds for business presentations, to striking works of pure art. Of course, particle brushes can’t (and aren’t intended to) replace traditional brushes, whose circular dabs slavishly follow the input path. Providing such a straightforward brush is child’s play for PD Particles and allows it to offer a few twists along the way. Using its Brush Settings palette, you can change size, opacity or step (the spacing between dabs) and add random positional, size, angle, hue, saturation and brightness changes. You can also manage Bleed, which causes your current paint colour to blend with the colours beneath it, and Dryout, which causes the dabs to fade as if the brush is running out of pigment.