Earlier we introduced sketches, renderings, and the depiction and performance of the underwater background . Today we introduce the production of water bubble brush .
The bubbles in the picture were drawn using a custom bubble brush in Photoshop. This method is much better than drawing each bubble separately, as I want to spend less time on this than on the background element.
First create the bubble image.
•Create a new white layer 500x 500 pixels, as the background layer.
•Use the Shape Tool to create a black circle in the center of the layer. (Fig 9)
•Rasterize the layer and open the layer's Type palette. •Click the Custom Blending box and adjust the opacity to 0%. This will give the circle a gradient effect.
•Click on the Inner Shadow Box. The inner shadow will be able to simulate bubbles forming a spherical shape. Set the shadow's opacity to 100% to get a nice solid black, and set the spacing to 0 so that the shadow can be applied to the edges of the circle. Make sure the size of the shadow is 100 or about 100. You can make a 25% choke to the solid edge of the bubble. You should now see something like the (Fig10) layer.
This is our most basic bubble. All needed to create a bright highlight. Using the shape tool again, make a small black circle and place it where you want it. (Fig 11) 
This is our final bubble image. To convert it to a system brush, open the Edit menu and select Define Brush. Name the brush 'Bubbles' and click OK.
Now, adjust your brush. Select the Bubble Brush Tool. Your bubble brush will be added to the bottom of the Brush Preset Picker menu. Select it and draw a stroke to see it (Fig 12).
Select it and turn on the brush paint. First, we want to have a river with bubbles. Bring up the river, and under Brush Tip Shape, set the interval to 100%. This build will determine how the brush shape will repeat.
If you click on the brush now, you will get a river with spaced bubbles (Fig 13). The next step is to introduce some variations in size.
Click on Shape Dynamics and set 'Size Jitter' to 0 to control the brush pressure. Now paint your brush, squeezing it lightly at the beginning of the painting and adding pressure to it as you paint. In the end, you will have something like in (Fig14).
Ah, so similar, but still a little too regular. The bubbles need to be spread out some more. Scattering causes bubbles to disperse from the center of the brush, where the brush normally paints. Make sure the brush's scattering is 300% and you should have something like (Fig 15).
Then, I defined my bubble brush and placed the bubble in the river, using a white 50% brush to paint it.
In the next section we introduce the performance of light effects.