How to make concentric coastal ripple effects with outer glow in Photoshop

[morikahn]

This is a method to quickly make that coastal ripple outline effect you've seen in old maps. It is an alternative to the slower method involving multiple layers, selection modifications, and stroke effects. However, it is only capable of making 5 concentric outlines, so if you intend to make more you'll have to use the slower method, or get creative with this one.

This tutorial assumes you are moderately proficient in photoshop, layers, and layer effects.






Step 1
Paint in the land mass. The land will need to be on a different layer than the water underneath.

If you are using line art to define the coast, like in the image above, I recommend that the pixels of the land interior match the outer edge of your lines. Otherwise, the ripples might start further inland.

This can be done in several ways; I suggest simply creating a selection from your line art, and using the Fill option on the layer where you've painted the land.


Step 2
Create an outer glow effect in the layer styles for your land layer.

• Set the outer glow Blending Mode to normal
• Set Opacity to 100%
• Set the Color to something that contrasts to the water
• Set Technique to Precise (this one is very important)
• Set the Size to how far you want the ripples to project (you can change this later)
• Set Anti-Aliased to true in the Quality settings.

You'll now have a fuzzy mess around your coasts.


Step 3
Customize the Contour of the glow to mimic the image on the tutorial.

If you've never created a custom contour:

• Simply click the Contour box, then click the displayed line to make vertices you can move.
• By default, these vertices will be curves. Check the Corner box to make them straight like the image above.
• You can adjust a vertex with your mouse, or you can use the input fields to place them exactly.
• It will take you a few minutes to get used to it. Vertices can't be moved past each other, for obvious reasons.
• Once you've made your contour, save it so you can quickly load it again when you need it for another map.

The spikes in the contour are where the lines will appear, the height of the spike is how opaque that line will be.

There is a limit of 15 vertices on a contour, which creates the hard cap of 5 coastal lines through this method.

I've included my contour file in the zip below if you want to just use mine and save some time.


Tips

• Once you've created the ripples, you can easily expand or shrink them with the Size slider.
• You can use the Range slider to push the first ripple outward or inwards towards your coast line.
• You can rasterize the ripples by opening the layer menu (right click on a PC) and select Rasterize Layer Style. This will transform the effect into standard pixels on the land layer. To get your ripples on a layer of their own, copy your land layer, set the copied layer Fill to 0% and then Rasterize Layer Styles. Delete the original outer glow afterwards.
• You can create new and interesting effects by adjusting the Contour lines. The alternative wave effect image above uses leaning triangles instead of spikes. The contour file for this effect is included in the zip below.

Photoshop contour files: ripples.zip

Note: these files were generated in photoshop CS6. I do not know how backwards compatible they are, but contours in photoshop haven't changed in a very long time so I'm assuming most people should be fine using them with earlier editions of photoshop.