Creating my own 3D images.

first i duplicate the background layer.

Then i go to 'image', 'adjustment', 'levels'

i then change the channel to 'red' and the 'output levels' to zero.

afterwards i change to the second layer and do the same but with the channel set to 'green' and 'red'

i then go back to drop down bar within layers and change it to 'screen'. you will probably notice there is now a blue and red layer.

afterwards i use the move tool to move the two layers a fraction apart.