Next, select the original rock layer which is under the rock copy layer in the layer panel. Alter its shape the same way as the previous rock copy layer.

Step 4

We have tried to combine the two rock layers. However, the combination is not well blended yet. To fix this, we will mask some part of the upper layer is that the rock copy layer. Make sure we are still active in the rock copy layer. Give this layer a layer mask which is simply achieved by clicking the layer mask icon located in the bottom of the layer panel. After clicking the icon, this will give a layer mask on the selected layer indicated by a white thumbnail next to the layer.

Make sure that the foreground is set to black and the background is to white by hitting D key on the keyboard.

Next we have to set the brush. Take the bush tool in the tool panel.

In the brush options bar, click the small triangle to open the brush picker box. Choose a very soft round brush meaning that the brush is set to 0% hardness. Set the opacity of the brush to about 20-25% and about 200 pixels size.

Now we are ready to mask the unneeded parts of the rock copy layer. Click the mask thumbnail to be active on the layer mask. With black color, stroke the brush on the parts of the rock copy layer in the document. This will hide the parts completely or make them transparently visible depending on the opacity of the black color stroked to them. The blacker the stroke is, the less visible they will be. I always start using a brush of low opacity (20-25%). After stroking the black brush on an image with a layer mask, there will be a black or gray spot on the mask thumbnail indicating that the parts are intentionally masked to hide or make them transparent. On the contrary, we can reveal the masked parts by stroking back white brush over them. The whiter the stroke is, the more visible they will be. Well, sorry again if I may sound fussy instructing this layer mask matter ;-) I just want to pay more intention on this layer mask because we will use much masking in the next steps and the result of this tutorial is greatly achieved by this masking is that how we hide parts of an image with a layer mask or how much we want to make them transparent. Go back to the rock copy layer, mask some parts of the image. The red mark indicates the parts we should stroke with a black brush to mask them. See the screenshot below:

Here is the result after masking.

Step 5

We will add another rock. Open the other rock image and cut out the red outlined part.

Step 6

Copy-paste the cut out into the main document. Scale its size to the size needed. I named this layer more rock.

Duplicate the more rock layer and flip it horizontally.

Alter the shape of this duplicate by distorting. To do this, activate the free transform tool. Right-click on the document. When the transforming option shows up, choose distort. Try to alter its shape by clicking, holding, and dragging the transforming points as indicated in the screenshot.

Then mask both more rock and more rock copy layer to have the result as below: