xsankor/unrealretroshaders

Retro PS1 Post Processing for Unreal Engine 4.

Retro Shader Pack by DaveFace

Current Version: v4 (06/06/2021)

This is an Unreal Engine 4 material & post-process pack for all your retro PS1-esque game needs. I may add more stuff over time but I think this provides the most common effects you'd want for this kind of project. Note that this pack is not intended as a 'realistic' PS1 imitation - if you want to mimic more of the PS1's strange rendering artifacts, I recommend Marcis' pack available on itch.io here.

Some functions are based on other people's work online, I've tried to include comments linking to their work where I can remember. If I've forgotten to give someone credit, my apologies, it isn't intentional.

Happy to accept contributions if anyone has improvements / tweaks / new shaders to add.

Getting Started

For Version 2 and above, I'm distributing this as a complete project. As of Version 4, I'm including a bit more demo content and I'm probably going to add a little prototype retro game, if I get round to it.

All you really need is the 'RetroShader' folder - you can ignore 'DemoContent' if you want. The demo content is optional, none of the core materials / material functions depend on it.

Unreal Engine Version

This has been made & tested in Unreal Engine version 4.25. It should work in subsequent versions though, as the functionality is pretty basic.

As of writing (June 2021) I have not tested this in Unreal Engine 5 - but it will probably work just fine.

Using the pack

To use the post-process material, drop 'BP_RetroPostProcess' into your scene - it doesn't matter where. The default settings should 'just work', but everything is commented to explain what's going on. Your main choices are:

• Whether to use YUV Colour Space, or simple posterise / colour banding. YUV is more faithful to the PS1, but does not handle very colourful scenes so well where you might want to push the available colours up a notch.
• Dithering method. There are currently two, and I would recommend sticking to accurate bayer dithering (the default) for now - I'm still experimenting with other dither methods. The 'hacky' version provided works well in some scenes, but for most it just messes with the brightness.

I would recommend creating your own Child Blueprint (Right click > Create Child Blueprint Class) and creating your own default settings. This also means that if I update the blueprint in future, any non-breaking changes will simply propagate to your own version without breaking your defaults.

Major caveat with V4 and above - To achieve the low resolution look, this system dynamically adjusts the console parameter r.ScreenPercentage to hit a target resolution, which drops the render resolution of the frame (see Unreal docs here). This does not get previewed in the editor viewport, even in 'Simulate' mode. You will need to be in a Play-in-editor (PIE) session to see it. For look-dev, you can get an approximation by dropping the 'Screen Percentage' amount to 50 in the viewport, by clicking the top left arrow.

For the full effect, you will also want your materials to use the retro functions - I'd recommend using the provided master materials to create instances from. If you need to integrate the functions into custom materials, affine warping and vertex wobble are created as reusable functions - to understand how/where to use them, just check the included master materials.

Make all textures use nearest-neighbor

A large part of the retro aesthetic is nearest-neighbor filtering on textures. This can be set on a per-material basis if you really want to - but it's far easier to make this a global setting using Unreal Engine's device profiles.

You can find this under Window > Developer Tools > Device Profiles

Click the tool / spanner icon under 'CVars' on your platform e.g. Windows (note - WindowsNoEditor etc. all inherit from Windows, so no need to edit each one). Then under Texture LOD Settings, for each texture group you want, open the drop-down and set the MinMagFilter to point. This makes those texture groups render with nearest neighbor filtering by default. I'd recommend doing it for the following:

• World (the most common)
• Character
• Effects
• Skybox
• UI
• Lightmap

Credits

Core Content

• YUV colour conversion / Bayer implementation by Jazz Mickle

Demo Content

• Texures based on images from www.textures.com
• Everything else is original - feel free to use it however you want!