# VDL Options dialog

Figure 1: VDL-Options dialog.

To understand the options in the top part of the dialog, consult Understanding the Display Generator.

Note that several of the options are useful only if SlipStream supplies a video source to be superimposed on the existing image. This is not possible in this release of the hardware.

## The CLUT bypass option

- While converting the source art, you need to set the CLUT bypass option for the image to force a standard VDL for any pixel for which the high bit is set.

- The program that displays the cel needs to set the high bit in the cel using the `SetCEControl()` function.

The frame buffer will now use the standard (system-supplied) VDL instead of the custom VDL for each pixel that has the high bit set-that is, for each pixel that is part of the specially prepared cel.

Note: You can have transparent and opaque cel pixels on top of an image that uses a custom VDL. Translucent cels will not work correctly even if you have turned on the CLUT bypass option because the cel engine assumes a linear ascending CLUT.