# Creating special effects using P-Mode

The 3DO hardware lets you draw a cel with translucency, smoke, and other special characteristics using a facility called P-Mode (pixel mode). By default, cels exported with the plug-in are drawn with P-Mode 0. You can create a mask in an additional channel and assign all mask pixels a different P-Mode.

## How to use an extra channel to brighten parts of a cel

To create a cel with enhanced luminance in some regions, follow these steps:

1. Open the cel in Photoshop.

2. Use the Magic Wand tool to select the area you want to mask. Hold down the Shift key to continue selecting interior areas.

3. Double-click on the Magic Wand tool to display the Tolerance dialog. Make sure Tolerance is set to 4 and Anti-aliased is checked.

   Note that while these settings often work well, you may have to change them to meet your needs.

4. From the Select menu, choose Inverse.

5. From the Select menu, choose Save Selection.

   If you previously saved a mask, the channel number of that mask is shown in a submenu and you have the option of overwriting that channel or creating a new one.

6. From the Window menu, choose Channels and select the channel you just created to make sure the mask looks right.

7. From the File menu, choose Export > 3DO CelWriter.

   The CelWriter dialog shows that a channel has been added. Make sure the newly created channel is assigned to P-Mode in the Channel Assignments region. Figure 1 shows the settings from a cel that has both a Transparency channel and a P-Mode channel.

   The P-Mode mask allows you to assign one of two different effects to each pixel in the cel. For example, you can make some pixels of the cel translucent and all others bright opaque.

   - All pixels that are black in the mask are saved as P-Mode 0.

   - All nonblack pixels in the same mask are saved as P-Mode 1.

   Figure 1: CelWriter dialog for saving a cel with transparent and P-Mode masks.

8. In the P-Mode Settings box, choose one of the P-Mode presets for P-Mode 0 to result in the kind of effect you want. P-Mode 1 usually remains opaque.

9. You may also create a new P-Mode setting following the instructions in Creating and editing a P-Mode preset

10. Save the cel and display it on your 3DO Station.