I received a lot of emails asking if I could explain how I created the pedestrian paths diagram in the previous post. To generate the line work, there are many ways this could be done. In the past, I probably would have used the spline tool in CAD. The line work could also easily be created in Illustrator. However, not many people know about or use the pen tool in Photoshop. It's similar to the pen tool in Illustrator but with some minor differences. In this case, I will be using the pen tool to create a path that I can tell the brush tool to follow.
1. Setup the Brush settings
I need to first set the brush settings because this is what I am going to use to add a stroke to the path created in the next step. The settings in this step will determine the thickness of the line as well as the color, hardness, and opacity. I chose a hard brush, 6 pixels big, at 100% opacity, and with black paint. You may need to draw a few lines to determine if you have the correct size.
2. Setup the pen tool and begin creating paths
Before choosing the pen tool, first create a new layer. The paths will not show up in the layers palette but the stroke that is applied to the paths will be drawn on this layer. Now, choose the pen tool and be sure the "Path" option is selected in the pen tool settings tool bar at the top.
With the pen tool activated, begin drawing the paths. To create the curved paths, click and drag when choosing the points on the path. This will create handles that can be used to control the size and shape of the curve at that point.
3. Stroke Path
Once you get the path where you want it, right click near the path and choose "Stroke Path". If this option is grayed out, double check that you have the new layer selected that was created in the previous step.
A second dialogue box will appear asking what tool to use for the stroke. We want the "Brush" tool since this is what we set up in the first step. Then choose "OK".
To finish the path, hit the enter. Repeat these steps to create each path.
4. Generate many paths at different levels of opacities
I want to create a hierarchy of paths revealing different levels of traffic intensity. This is shown through both a density of lines and levels of opacity. For this image, I created three different path layers. The first layer was set to 100% opacity, the second to 50%, and the third to 15%.
5. Add line work glow
I want the line work to have more of a presence in the illustration, so a slight glow will be added. This is done simply with the brush tool. I used a soft brush, 90 pixels big, and set the opacity to 12%. Where the lines are dense or converge together, I layered in some black paint.
I also duplicated the dark paths layer and applied a Gaussian Blur filter.
I removed the background so that this step could be seen a little more clearly.
6. Add Color
To further punch up the paths, I'm going to add color. To make things easier, first merge all of the path layers together. It may be best to first duplicate these layers and turn off visibility so that you will still have the original individual layers available to edit if needed later on down the road. To merge, select all of the path layers, right-click on one of the layers, and choose "Merge Layers".
Once the layers are merged, right-click on the new single layer and choose "Duplicate Layer".
With the duplicated layer selected, choose "Image>Adjustments>Hue Saturation" at the top. In the dialogue box, first check the "Colorize" box. Then move the "Lightness" slider to the right to ligten the line work. Also move the "Saturation" slider to the right to increase the color. Finally, adjust the "Hue" slider to the color tone you prefer.
7. Set Layer to Overlay
Finally, set the blend mode of the colorized layer to "Overlay". This will help blend the color into the image and let the darker line work underneath show through.
The final result is a series of smooth curvy lines created without the need to jump into another program such as Illustrator or CAD.