Enhancing Photoshop Compositions Using Displacement Maps

Ever try adding some textures to a design element but the final outcome just didn’t look realistic? You may have tried turning a wooden table into a steel one or transforming a pair of jeans into corduroys. Either way, if you’ve ever found yourself wondering how to realistically map a texture onto a given surface, then this tutorial is right up your alley.

Mapping textures (as it’s technically called) is a practice that can greatly enhance your compositions and open up new opportunities for customization in your designs. There are no set in stone rules for applying textures since every situation is different and requires its own approach along with post-tweaks. However, one very helpful and I’d venture to say necessary tool is Photoshop’s Displacement Map.

The main focus of this tutorial is to show how the displacement map function works. For our example, we’ll be mapping grass textures onto a barren dessert. This landscape was specifically chosen because of its rocky terrain. Uneven surfaces generally require more attention in order to keep everything looking realistic so this image serves as an especially good illustration of Displacement Map usage.

The raw materials for this project are listed below:

Monument Valley Wallpaper (courtesy of FunWallz.com)
Monument Valley Wallpaper with Road (In my example, I added a road to give a sense of perspective. You can choose which ever version of the photograph you like)
Grass Texture

Let’s get right into it.

While very dry, this desert still has signs of plant life. We want to keep the existing greenery so the first step is to use the wand tool and select the shrubs. Throughout this tutorial, it will be up to you to decide how detailed you want to be. Some may want to highlight every branch and individual leaf while others may opt for a fairly loose selection. It’s completely up to you. Since these tutorials are meant to illustrate principles, I recommend setting your own precision levels for this exercise. Once you have the shrubs selected, copy then to a new layer (Control – J) and label it “Shrubbery”. You can now hide this layer for later use.

Next, with the background selected, select the areas where our new grass will grow. This will basically be the entire ground area plus some areas in the distant background. We don’t want those large rock structures to have grass growing up their sides because quite frankly, that might look a little strange here. However, I did leave a plain of grass growing on top of the center plateau. Once you have the selection, copy it, open a new file,  and paste it into a new file. Tip: Whenever you have an image copied to the clipboard and make a new Photoshop File, Photoshop will set the new file to the exact dimensions of the copied image. I’ve tipped my hat off many times to the developers of Photoshop for that one.

This new file will serve as the Displacement Map. With the selected copied grass layer pasted into the new file, desaturate the layer and apply a levels adjustment. Here is where we set up the magic. In short, a Displacement Map receives its instructions based on contrast. It uses the difference of white and black in an image to determine how to apply a given texture. So for this step, we want to increase the contrast as much as possible to deliver the clearest possible instructions. Using the level markers, adjust your image so you have very bright whites, very dark shadows, and very little gray area. Below is a screenshot of the level settings I used.

Once you’ve done this, apply a Gaussian Blur with a setting of 3 to the layer. This helps soften the transitions a little more and ultimately, will give you a more realistic end result. You should have something that resembles the image below.

Save the image as “displacement.psd”.

Open up the grass texture file and drag it into the original document, placing it just underneath the “Shrubbery” layer. Call this new layer “Grass”. Position the layer so that it covers the areas where you want the grass to grow. With this layer selected, choose Filters  > Distort  > Displace. Set the horizontal and vertical scale to 15. The higher the number, the more dramatic the displacement. After you hit “Ok”, you’ll be prompted with a selection window. Locate the “displacement.psd” file you just created and select it. Photoshop will now take instructions from the selected file and alter the “Grass” layer accordingly. Your result should be similar to the image below.

It’s a far cry from being a realistic composition but if you look carefully at the grass, you’ll see that it has been distorted according the topography of the terrain. It may be hard to tell now but with a few tweaks, you’ll be able to appreciate the work of the Displacement Map.

Change the layer blending mode to “Overlay”. You’ll immediately see the rocky ground show through the now yellowish grass. In this mode, it’s easier to see how the grass conforms to the contour of the ground.  Add a layer mask to the “Grass” layer and using a soft brush, erase the unwanted grass in the mountain areas and sky. If you’re using the landscape version with the road, make sure the roadway on the right side isn’t covered in grass.

In order to get the grass looking richly green, we could technically play around with the Hue Saturation levels. However, in this case, we want to go with something more realistic. Select the background photograph layer and add a Black / White adjustment layer to it. By removing the background colors, you’ll see how the grass layer turns into a rich green.

The only issue is that the rest of the scene just got boring and dull. Start erasing the mask for the Black and White adjustment layer to bring back the color to the rest of the photograph while leaving the green areas you want to keep. Bear in mind that the entire foreground doesn’t have to be this shade of green. As you’re adding color back to the image, you can change the opacity of your brush to allow different amounts of green to show through. Doing this will actually make the composition look more realistic.

At this point, everything should be looking noticeably “livelier”. Next, unhide the “Shrubbery” layer and using Hue Saturation, adjust it to a desired shade of green . Once again, exactly how green you want the plants to be is completely up to you. Just make sure it looks alive 🙂  Depending on how precise your initial selection was, you may need to clean up some of the shrubbery edges. Add a mask and soften any harsh transitions that you see.

Next, duplicate the “Grass” layer, drag it just above the “Shrubbery” layer, and set it to clipping mask. For more information, on clipping masks, check out our previous tutorial by clicking here.  Set this copied grass layer to an opacity of 85% and a blending mode of overlay. This will add some additional grassy texture to the shrubs which truthfully looked like they were struggling to begin with. As a finishing touch, add a subtle drop shadow effect to the “Shrubbery” layer. Play around with the actual settings so the composition looks as real as possible. The drop shadow will make the shrubs pop out of their new grassy environment. Based on my settings and configuration, my grass was still looking a tad dark. I created a new layer, positioned it at the top,  and used a soft white brush to paint the areas I wanted to lighten. I then set the layer to Overlay and reduced the opacity to 80%. The final result is below.

And there you have it: Using Displacement Maps, we’ve given Monument Valley a lawn that Mother Nature would be proud of. In this tutorial, we kept the everything believable by adding natural grass to a natural landscape. At the same time, learning is all about exploring so don’t be afraid to take the principles here and have fun. Take some grass and map it to a pair of jeans or get some stone and map it to the outer frame of an LCD monitor. In the world of creative exploration, it doesn’t have to be “realistic” in order to look real. Remember, it’s more important that you creatively apply these principles rather than remember a set of defined steps.