This is the text that we are going to add the 3D effect to.

After typing it out and flattening the text, we duplicate the layer so as we can edit them both and change the Levels.

We go on to 'Image', 'Adjustments' and 'Levels'  where we can change the colours of the image layers.

The top layer is changed to Red and the Output Levels to 0

The background of the top layer is now a different colour and we need to change the colour of the back layer.

When the other layer is selected, go back on the Levels box and set the Channel to green and the Output level to 0

These are the colours of the layers.

With the top layer selected, choose 'Screen' out of the Layers tab.

When the top layer has been moved down and right slightly this is the effect you get with the text and it appears to be jumping out at us.