Normal Map Photography

Introduction



If you find this method helpful, or if you have a suggestion, let me know at richardryanclark@gmail.com.

Kind souls have translated this tutorial into Czech and Japanese. Further translations are always welcome!





Materials







- Digital camera, preferably with a tripod.

- Computer with Adobe Photoshop, or a similar image editor.

- Movable light-source.

- Subject. (In this example, Subject is a bowl of peanuts.)





Camera

Computer

Light-Source

Subject





Before beginning this tutorial, you will need the following items:- Digital camera, preferably with a tripod.- Computer with Adobe Photoshop, or a similar image editor.- Movable light-source.- Subject. (In this example, Subject is a bowl of peanuts.)

Step 1:



Place your camera in a fixed position, and photograph your subject four times, lighted from each of four cardinal directions, as in the examples below.



You may want to experiment with the elevation of your light. The subject should be lighted from a low angle, but not so low that it's obscured by its own shadow.





lighted from above lighted from the left lighted from below

lighted from the right







Step 2:

Convert your photographs to grayscale, and crop them as desired.





lighted from above lighted from the left

lighted from below

lighted from the right











Step 3:

Create a new image, using your above-lighted photograph for a green channel, and your left-lighted photograph for a red channel.



This image will be hereafter called "Above&Left."







Above&Left

green channel = lighted from above

red channel = lighted from the left



Step 4:











Choose output levels 127 and 0, and then click OK.



Open the levels dialog for "Above&Left."Choose output levels 127 and 0, and then click OK.

Above&Left:

after levels adjusted



Step 5:

Create a new image, using your below-lighted photograph for a green channel, and your right-lighted photograph for a red channel



This image will be hereafter called "Below&Right"





Below&Right

green channel = lighted from below

red channel = lighted from the right



Step 6:











Choose output levels 128 and 255, and then click OK.



Open the levels dialog for "Below&Right."Choose output levels 128 and 255, and then click OK.

Below&Right:

a fter levels adjusted







Step 7:















Set the top layer's blend mode to "Overlay," and then flatten your image.





Paste Below&Right into a new layer over Above&Left.Set the top layer's blend mode to "Overlay," and then flatten your image.

Normal Map:

after image overlay



Step 8:





Fill your blue channel with a light color. You may want to experiment with the shade; a lighter blue will yield a smoother normal map.





Normal Map:

blue channel lightened





At this point, your normal map should be finished and ready for use.

Step 9: (optional)









If your game engine supports parallax mapping, you can use CrazyBump to create the necessary heightmap.

Displacement Map:

from CrazyBump



Further Examples:









Subject:

Decorative Cross

Normal Map:

after steps 1 - 8

Displacement Map:

from CrazyBump



Subject:

some rocks

Normal Map:

after steps 1 - 8

Displacement Map:

from CrazyBump



3D Renderings:











