How to Bump Map in Photoshop (CS3)

I got a few emails asking me how I created the leather for the Pac-10 iPhone Wallpaper or if I just used an image from a car interior or something. I created the whole thing in Photoshop and figured that it would probably make a decent tutorial. The secret is bump mapping.

Final output for this tutorial is going to be a desktop wallpaper for a 30″ Apple Cinema display. Document dimensions don’t really matter and you can work at whatever dimensions you please. All the principles outlined in this tutorial will hold true.

What is Bump Mapping?

Bump mapping is essentially a technique used in all sorts of programs that creates the illusion of depth on a surface. Photoshop can do it along with 3D programs like Maya, 3DS Max, Lightwave, etc. I’m sure everyone has at some point tried blending two layers in Photoshop with each other in hopes of getting a nice looking texture. But, sometimes that texture fails to look convincing and its here that bump mapping can help solve the problem.

Step 1 – Prep

The first thing you need to do is find your desired texture. If you don’t know about cgtextures.com go ahead and lightly slap yourself on the back of the head for me. Just kidding. Don’t hit yourself, especially if you are in public. Anyways, cgtextures is an unbelievable resource that you should get yourself accustomed to. I went and chose texture #13224. It’s a nice simple leather to work with.

Step 2 – Base Color

Now, create a new layer and fill the layer with a very dark, almost black, solid color. I used #181818. As a general practice I don’t like to use 100% white or black in my work because those colors (even though they aren’t technically colors at all) don’t occur in the real world. Unless we are talking about a black hole where everything is devoid of all light we are never going to experience a true black in our day to day lives.

By the way, go ahead and save your file as something appropriate so that your not working from a temp file.

Step 3 – The Bump

Now the guts of the tutorial. Let’s bump. You will need to place or copy and paste your leather texture into your document. I prefer placing because it will treat your texture as a smart object. That doesn’t matter here, but it’s not a bad practice to get into. To place something just select File > Place… and browse to your desired file.

It is then going to place that file in your document with resizing handles. Resize the leather texture so that it takes up the entire workspace.

We now want to apply a light gaussian blur so that the texture doesn’t have a harsh quality once its bumped. Go to Filter > Blur > Gaussian Blur and enter a setting of 1px.

Next, go to your channels pallet and select the channel (red, gree, or blue) that has the most contrast between black and white. In this case I like the blue channel. With only the blue channel selected, I want to right click on that chanel and select Duplicate Channel…

You will see the new channel called Blue Copy at the bottom. Go ahead and rename that to “Bump.” After you’ve renamed that chanel go and check the RBG eyeball to make all the channels visible again, with the exception of the new “Bump” channel. Finally, go back to your Layers pallet.

You are essentially done with your texture layer now, so go ahead and click the eyeball to make the leather texture invisible. Make sure layer 1, or the layer with your dark color, is selected. Then go to Filter > Render > Lighting Effects…

In my case I have chosen the following setting below. I’ve chosen a very light overhead spotlight to act as my light source. The properties box is pretty standard. You’ll want to note the Texture Channel I’ve chosen. Earlier we named our duplicated channel “Bump.” And that is precisely what we want to use for our texture. Ensure that White is high is selected. And please, understand the art of being subtle. Sure, you can bump up the height to a 100 and have a really <sarcasm>awesome</sarcasm> looking texture. But that isn’t what leather looks like. So please, leave it at a low number and don’t screw up the tutorial. :)

Congratulations! You’ve bumped. You’re result should like something like this. (Click through to see larger version)

Step 4 – The Holes

The leather needs to breath a little bit, so we need to add some holes. These will be quite small. I’m going to create a repeating fill pattern on a new layer. If you don’t know how to create a fill pattern see my tutorial here.

This is the pattern I’m using. It’s a 30px by 30px square and the holes are 3px in diameter.

Create a new layer in your document above all the others and name it “Holes.” Ensure that your foreground color is #000000 and simply select your paint bucket and fill it with your newly created pattern. (I know I’m breaking my own rule of 100% black, but it’s okay for this situation.) You now have a whole bunch of black holes, but they don’t look real yet.

We’re now going to add a layer style to our Holes layer. Select the Add a layer style… button at the bottom of your layers pallet to get the dialogue box. We are actually going to add a drop shadow, but it is really serving as a highlight instead. With our light source being overhead there is going to be a highlight along the bottom of each dot/hole. Your setting should like like this:

Good. But you’ll notice there is something wrong here. The highlights extend evenly into the darker regions of the workspace. But, in theory, the less light light there is the weaker the highlights will be. So let’s fix that.

Right click the little fx icon on your “Holes” layer and select Create Layer. This will separate the layer effects out from the layer itself. Pretty handy.

Click okay when the warning box pops up. We now have separate layers. Set the blend mode for your original “Holes” layer to Darken. Select the Hole’s Drop Shadow layer and go to Filter > Render > Lighting Effects… I chose the following settings:

Much better. We now have a more realistic lighting setup. Personally, I still like to create an additional layer and then very lightly airbrush the darker regions by hand. The highlights still seem too apparent to me, but I’ll leave that up to your preference.

You could stop at this point or continue to add embellishments such as stitching and a chrome logo like I did for the iPhone wallpapers. Hopefully this has given you good insight on how to take advantage of bump mapping. Here is my final product.

Feel free to use it as a wallpaper if you’re a Duck fan!