Getting Started: The Shaders

The Cathode Retro shaders are built to work together - they are really one big effect, broken up into a series of passes.

There are three main phases to Cathode Retro:

• The Generator: Convert an RGB image into an emulated NTSC scanline texture.
• The Decoder: Convert an NTSC scanline texture back into an RGB image.
• The CRT Emulator: Take an RGB image and run it through an approximation of a CRT screen.

It is possible to use these pieces separately, of course - you can run the CRT Emulator directly on an RGB input texture if you do not wish to have any of the NTSC artifacts (for instance, if you're emulating a system with a direct three-component connector, like component video or VGA.

Additionally, if you are decoding a real NTSC signal, if you have code that breaks it down into a set of scanlines (the visible portion of the scanline, not including all of the additional pieces of the signal) and a set of per-scanline phases of the colorburst, you can feed that directly into the Decoder to get an RGB image out.

But, if you want to use the whole system to emulate an NTSC signal run through a CRT, you would start with the Generator.