#relight tutorial

[You can also find this tutorial over at imgur and patreon]

ReLight is a premium shader for ReShade made by Marty's Mods (Pascal Gilcher). It allows you to add four new lights to your scene that help illuminate, and create realism and drama. To download and use ReLight you need to subscribe to the Path Tracers tier on Gilcher's Patreon to get access to the iMMERSE Ultimate package of shaders. Once subscribed, you'll be prompted to link your Patreon account to discord, and then you'll be granted access to his discord server, and, most importantly, to the Path Tracers discussion channel and the Downloads Level 2 channel, which is where you will find ReLight (along with the other premium shaders included in that tier). 

Be sure to also download the up-to-date free iMMERSE shader package, because you'll need the Launchpad shader and some of the other included files.

The following guide is for the older qUINT_relight.fx version of ReLight. The latest version of ReLight is MartysMods_RELIGHT.fx, released on 31st December 2023. Many of the settings have changed in the newer version, but you can still use this guide to help understand how to enable and position lights. The guide will be updated/rewritten once I've had time to properly play around with the new version. You can continue to use the older version if you'd prefer.

When you turn on ReLight in the ReShade menu you'll be greeted with these settings. Yours may look different because I've used it a lot and it remembers your last settings.

Take a look at the settings at the top.

Use Smooth Normals = On

Trace Shadows = On

Filter Shadows = On

Use Temporal Supersampling = On

Shadow Mode = Trace All

Shadow Quality = Ultra (change this if you get bad performance)

Shadow Sharpness = I have mine set around 0.65 but you can play around with whatever looks best

Z Thickness = Play around with this too. It controls how realistically shadows fall on and around objects

At the very bottom of the settings is Visualize Light Position. Turn this on so you can easily see where your lights are.

Now we can turn on one of our lights. Remember, it remembers your previous settings so yours will look different to mine the first time you use it.

Under Light 0 check the Active box.

You should see a big circle appear somewhere on the screen. If you have any object close enough to it, you should see them get brighter. If nothing is close to the circle you may not see any difference.

You can see a difference between this screenshot and the last - Shadowheart's face is brighter.

Now it's time to move the light where we want it and change it to a colour we like.

Under the Active box you'll see a row of 3 boxes containing numbers, next to the word Position. These control the coordinates of your circle of light in relation to the screen. You can place your mouse inside these boxes and move it while holding down left-click to change the value a little like a slider.

Left box = moves the circle left/right

Middle box = moves the circle up/down

Right box = moves the circle forward/back

In this shot I've moved the circle of light over to the right and a little further back so it better illuminates the front of Shadowheart's face.

Next you can choose the colour of your light.

In the row below Position you'll see it says Tint. Click on the coloured box next to Tint and it will bring up the colour picker you see in the screenshot. Choose your colour from here. Click anywhere in the main ReShade menu to close the colour picker.

I adjusted the position and the tint a little more until I had it exactly where I wanted it. You can see a darker circle now over in the top right of the screen (my mouse cursor is hovering over it to make it easier to see).

You can use the Intensity slider (directly below Tint) to control how bright the light should be.

You may need to go back and forth between the Position, Tint, and Intensity settings until you get just the right effect.

Here's a reminder of what the picture looks like without that added light. Compare it to the screenshot above to see how great our new little light has been at helping illuminate Shadowheart.

You can turn individual lights on and off whenever you want by checking or unchecking the Active box next to the light in question. It will save your settings.

Now I want to add a second light. I've moved my ReShade window over a little so I can see what I'm doing.

I turned on the Active box under Light 1, and positioned my new light where I wanted it. Look over to the left of the statue in the background. You'll see my mouse cursor, and directly above it is a tiny blue circle. That's our second light!

The further you move the light away from the camera (using the right-hand box under Position) the smaller the circle gets, because it's further away!

I made this light blue, and I turned the intensity up quite high. This has helped illuminate the statue and added nice shadows that help give it some depth.

Here's a screenshot to remind you what everything looks like without any of the ReLight lights I added.

And here's a screenshot showing how everything looks with ReLight turned on and my two lights in action. I chose a subtle effect because I just wanted to draw attention to Shadowheart's face and to the statue behind her.

When you close the ReShade menu the circles that helped you know where your lights were will go away, but the light they cast will remain. Notice how you can't see the two circles in this shot?

You can also uncheck the Visualize Light Position box if you want to hide the circles while keeping the ReShade menu open. This can be helpful if they're obscuring parts of the scene that you need to see while you continue editing.

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And that's it! You can add up to 4 lights and control them independently from one another. You can use them to just help illuminate a character for a portrait, to add drama with bold lighting, or to increase the realism of a scene with better shadows and light falling where you would expect it to. If you have a big fiery sword you can add a light to it that makes orange light cast onto the character who is holding it, which can look really cool. The only limit is your imagination.

Hi anon!

It's not a massively involved shader, it's really simple, so a full tutorial would probably be a little over the top. Using it in TS4 is no different to using it in any other game.

The first thing I'd do is look at the preprocessor definition section at the bottom of the shader settings and change number of lights to 4 and hit enter. It'll reload and then you'll have 4 different lights to play with.

For the settings at the top, you want Use Smooth Normals turned on, and then all the boxes under Shadows ticked. For Shadow Mode you'll get the best quality with Trace All selected, and Ultra for Shadow Quality, but you can play around with these if your performance suffers (bear in mind I'm using a 980ti and hotsampling to larger resolutions and I'm fine with those settings).

Leave Shadow Sharpness at its default unless you want to go for a specific look, and you can keep Z Thickness at default too. You can play around with Z Thickness if shadows look like they're starting or ending in weird places. They're never going to be 100% accurate anyway, but you can sometimes coax them into not being truly awful.

One of the most important settings is down at the bottom: Visualize Light Position. Turn this on and it'll show you a round dot where your lights are positioned. This is really useful for lining them up exactly where you want them. Then, when you're done, you can turn them off (although they will disappear when you close the ReShade menu anyway, but this setting is useful for people like me who sometimes keep the ReShade menu open when taking screenshots so I can keep tweaking).

You'll see 4 sections that each start with a checkbox that says Active. Those are your 4 lights. Tick the ones you want to use. Then you can start moving them.

Next to Position there are 3 boxes, and they each represent respectively: left-right, up-down, backwards-forwards. Play around sliding each of them and see where your dot of light goes. You'll quickly get the hang of how to move the lights around using those position numbers.

Below that is Tint. It's easiest to click on the box of colour and colour pick than it is to manually change the RGB numbers. This controls the colour of your light.

Below that is Intensity. I think by default the lights are set up at the maximum level of 1.00 but that's super super bright, so bring that down considerably. You can use this to fine tune exactly how much illumination you want once you've set up the position.

And that's really it. You can use the lights to add more accurate light fall-off and shadows from in-game light sources like lamps, streetlights, windows, etc. You can also use it to just brighten a character's face a bit more for a clearer picture. Or you can really go to town and add completely fake and dramatic lights. It's up to you.

If you find that 4 lights isn't enough, you can't add more without editing the actual shader code. However, you can just duplicate the shader, so then you can have 8 lights, or 12, or 16, however many times you duplicate it.

To duplicate ReLight, create a copy of the shader in your shader folder, and give it a unique name (for example, qUINT_ReLight2.fx). Then, open it up in a text editor (I use Notepad++) and scroll all the way down to the bottom. You'll see a section that says

technique qUINT_ReLight

edit that so it matches the name you gave your copy, so in this case

technique qUINT_ReLight2

Then you can use them both alongside each other. I do start to experience a performance impact when using a second version, so bear that in mind.