BikeCAD version 13 features a new Freehand drawing tool accessible by clicking the paint icon and choosing the Freehand tab in the Paint dialog box. Clicking the Start new freehand sketch icon launches an interface for configuring our new drawing. The mask icon determines whether our drawing will appear behind our model, or whether it will appear only on the frame but behind any decals, or whether it will appear in front of the model. For this example, we'll select the second option and begin by drawing a pinstripe starting at the BB and traveling along the down tube to a point on the head tube. Each time we left click, a new point in our shape is established. We can continue to draw our pinstripe along the head tube and back along the top tube to the seat stays, the rear dropouts and finally back to the BB along the chain stays. Clicking the green circle will stop new points from being added to our shape. We can change the color of our pinstripe by clicking on the outline color icon. In this example, we'll choose yellow. The thickness of the outline is defined in the thickness field. A thick line like this allows us to observe the difference between the three corner treatments. The first option gives us a square corner, the second option round and the third option is beveled. I'll choose round. I'll make this line a little less pronounced by switching to a 3mm thickness. By checking the box next to the fill color icon, we can fill this shape with red. Clicking the fill color icon allows us to switch that fill color to another shade of blue.
Clicking the Start new freehand sketch icon again gives us a fresh new sketch with the same colors as our first sketch. In this example, I'll turn off the fill and set the outline colour to pink. Picking a series of points on either side of the seat tube gives us these zigzagging stripes.
Although it is simplest to work on one sketch at a time, you can add points to several sketches all at once. As a demonstration, I'll configure a new red line with a thickness of 2500mm and a rounded end. I'll set this line to appear behind the bike. Before, I start drawing, I'll add more lines of different colours decreasing the line thickness with each new line. I'll finish it off with a line of the same color as the background. When I begin drawing, you'll see a rainbow arcing across the sky.
The freehand drawing tool can also be used to represent items that aren't otherwise accounted for in BikeCAD. For example, I can create a thin black line in the foreground and draw in the profile of a bikepacking frame bag. I can enable the fill tool and choose a dark gray or whatever colour I prefer.
Be aware that if we switch from the paint display mode to the no hidden lines display mode, the outlines of our freehand drawings will assume the outline color of the BikeCAD model and the fill colors will assume the color of the background.