This tutorial will show you had to add realistic cracks to an eggshell in Photoshop.
We have our beginning images here:
Step 1: Prepping
Open them both in Photoshop. Go to the cracks image. In the menu, go to Image>Adjustments>Threshold and slide the slider around until you make it black and white. Hit OK. *Note: This does not have to look perfect, it is simply a guide.
Copy your new black and white cracks picture and paste it into the file with the egg. You may have to resize it some, and rotate it a little to get the cracks in a decent arrangement.
Now, go to Filter>Distort>Spherize. In the little preview, you might try zooming out a bit so you can see what you’re doing. You just want the cracks to be kind of curved, since the egg we’re using them has a rounded surface.
Change the blending option for the cracks’ layer from “Normal” to “Darken” in the Layers Window. This will keep the black lines visible and make the white parts transparent/invisible (they are still there, just can’t see them when using this option).
While you’re on this layer, once you’ve positioned your cracks layer, go ahead and erase the space outside of the egg, since the cracks won’t be going out there. This is really optional, I just like having things a little cleaned up as I’m going.
Step 2: Cracking it Open
Go to your egg layer. Take either the Pen Tool or your Polygonal Lasso Tool and draw lines across the top of the egg to mimic some of the cracks you see, you could even follow some of the lines from your other layer if you’d like. You’re going to delete this part of the egg. This is eventually going to be the backside of the egg.
Create a new layer, above the egg’s layer. It can be above the cracks too if you want, but not necessary.
Again, using either your Pen Tool or Polygonal Lasso Tool, trace along some of the lines, creating an opening on the top part of the egg. Fill it in with black, or a color that works well on the inside of the egg. You can always adjust this later. Don’t forget to Lock Transparency on this layer to avoid issues layer on (this is located in the Layers window).
Step 3: Highlighting the Opening
Create a new layer, over top of the previous layer we created, the opening’s layer.
While still on your new layer, hold down CTRL and click on the layer with the opening. This will select the around the shape on the opening’s layer. Now, we’re going to inverse our selection (CTRL+SHIFT+I).
Using your Brush Tool, with a Hard Round Brush, and a smaller size, draw in some highlights on the edge of the broken shell. Be sure you’re on that new layer!
You don’t have to be perfect with the your first sets of lines for highlights, but it makes it easier if you take a little bit of care where you place them. Once you have the highlights where you want them, use your eraser and clean them up.
Step 4: Applying More Cracks
Yes, create another new layer, again on top of the other layers.
Depending on how visible the cracks are on our previous layer, you can either use the Magic Wand Tool and while you’re on the layer with the cracks, click in one of the spaces to select it; or you can just stay on your new layer, and use that Polygonal Lasso Tool and trace around the shapes. Hmm, that’s a really long sentence… Well, however you do it, you want to select a shape or two.
Hide the cracks layer and invert your selection (CTRL+SHIFT+I).
Use the eyedropper and select a darker color from the egg.
Using the Brush tool and again a hard round brush, carefully go along a couple of the edges of your shape. This is going to create a slightly raised section of the broken pieces of the egg, to give it a little more depth.
Continue these steps with other shapes to create even more cracks. Don’t overdo it, you want it to look realistic.
Step 5: More Highlights
Preserve the transparency for your newest layer, the one with the cracks you just made yourself.
Using the eyedropper, select a very light color of the egg shell.
Now, we’re going to select the Brush Tool and use this color with a Soft Round brush.
Lighten up some of the lines on your new cracks layer with the Brush Tool. When lightening these lines, the cracks will look even better.
Now, the last thing we’re going to do is make some of these broken pieces a little bit lighter than the others, since they are raised.
Figure out which ones you want the lightest and draw around them with one of your lasso tools.
On a new layer, pick your Brush Tool and armed with the same Soft Round brush, add some white/light eggshell white. Adjust the transparency of the layer to make it more subtle.
Finished!
Don’t forget about the cracks all the way around the egg, like in the back of the opening we made.