A displacement map can be created in Adobe Photoshop to create the effect of ripples in your water reflections. We want the ripples in the reflection to be more pronounced at the bottom of the screen than the ones farther away.
The displacement map is used with the Displace Filter in Photoshop (located under the Filter Menu – Distort – Displace) to give the water ripple effect to the Photoshop Layer with your reflection.
These displacement map files can be stored in a folder or on your computer’s desktop and reused for multiple water reflection images.
I’ve also written a blog on how to create water reflections in photoshop. I’ve written this as a separate blog because displacement maps can be created ahead of time and used when processing water reflection images in the future. The Water Reflection Blog was also getting pretty long.
Steps to create a Displacement Map for your Water Reflection Images
1. Create a New Document in Photoshop. Under the File Menu select New. Make the document have: Width = 600 px, Height = 1000 px, Portrait Orientation, Resolution 240 px / inch. Background Contents = Black
2. Unlock Layer 0 (Background Layer) by clicking on the lock icon on the Background Layer
3. Under the Filter menu select Noise – Add Noise. Set the Amount = 400%, For Distribution select Uniform. Check the Monochromatic check box. Click OK.
4. Under the Filter menu – Select Blur – Gaussian Blur. Set the Radius to 1.3 pixels. Click OK.
5. We are now going to work on the individual color channels. In the Photoshop panel with your layers, click on the Channels tab
6. Click on the Red Channel. All the other color channels should now be inactive. Under the Filter menu select Stylize – Emboss. Set the Angle = 180, Height = 1, Amount = 500%. Click OK.
7. Click on the Green Channel. All the other color channels should now be inactive. Under the Filter menu select Stylize – Emboss. Set the Angle = 90, Height = 1, Amount = 500%. Click OK.
8. Click on RGB channel. All the color channels should be active.
9. Click on the Layers Tab
10. Duplicate the Layer – Ctrl J (Windows) or Command J (Mac)
11. Use the Zoom Tool (Magnifying Glass) to zoom out so the image is small on the screen. Hold down the Option Key (Mac) or Alt Key (Windows) to zoom out. You can also click on the Magnifying Glass with the minus sign at the top of the window to set the Zoom Tool to Zoom out.
12. Go to Transform Mode. Ctrl T (Windows) Command T (Mac).
13. Right click on the image and select Perspective.
14. Stretch the Image. Drag the bottom corners out on the image so you have a wide triangle. You can even drag beyond the screen if you want really wide ripples. Click check box on top of screen when done.
15. Under the Layer menu select Flatten Image
16. To be used as a displacement map the Image must be converted to 8 bits / channel. Under the Image menu select Mode – 8 bits/channel.
The file must be saved as a Photoshop PSD file.
19. Under the File menu select Save As. Name the file something like Water Ripples Displace Map, make the format Photoshop. Save the file to your Desktop or a file folder you can quickly access. Click Save.
You may want to create and save a couple of displacement maps with a different amount of stretching. Some images may work better with a narrow stretch. For example, images with a lot of vertical shapes (buildings, sailboats), I feel work better with a narrow stretched displacement map.
That’s it. You’ve now created a displacement map to create reflection images in Photoshop.
Written by Martin Belan