How do I create weather particles such as rain or snow?
Katherine Phelps, England
Answer Bram replies
I would avoid using a custom brush to mimic falling rain or snow, and instead move, scale and rotate layers of particles. Ask yourself how those particles appear in real life. For example, snow doesn’t appear in a straight line in front of you, but instead falls over a large area. If you were to take a photo of it, there would be snowflakes close to the camera but also far away from it, resulting both in sharply defined flakes or more blurred forms.
I start by placing my particles above all other layers and put a black layer behind them to see what I’m doing. My approach is to paint a middle layer of about 50 crisp snowflakes. I then duplicate that layer several times and fill the canvas up by rotating and scaling them slightly.
I then merge my layers, duplicate the new layer, apply Gaussian Blur, reduce its Opacity to 50 per cent and scale it up about four times. I’ll often erase some of the closer flakes, because they can quickly get in the way of key areas of the painting.
I duplicate the layer again, or enlarge it if necessary. Once I’m happy, I delete the black layer and set the snow layers to Screen mode. Voilà, a cosy winter wonderland!
Try to keep your particles on a separate layer on top. This means you
can toggle them on and off at will.
Flying sparks differ in intensity. So instead of white snowflakes, create yellow and orange stripes, duplicate the layer, blur it, and blend using Color Dodge.