Lighting Control in Post - For people who can't make up their god damn minds until they're editing.

[SvenBrimstone]

As a lot of you probably know seeing my screenshots (though I haven't posted them as frequently lately), I do a LOT of stuff in post. That's where effects come in, that's where I can fiddle with colors, fix minor posing mistakes, etc. Something that CANNOT be easily done is major changes to lighting. Whatever lighting was in the picture you took, you're stuck with. This also means that you are limited to whatever the source engine can light, meaning that if you hit the limit and your computer (or the source engine itself) starts to fail, you are shit outta luck. This always bothered me, especially the part where in some HUGE scenes, the engine would break when I tried to light everything. So, here's a solution, for those of you who REALLY like to fine tune your edits before you post them. This is a fairly simple tutorial, as the concept itself isn't too difficult. What this allows you to do is fairly simple: [B]Turn on and off lights in your scene, and adjust their intensity, in post.[/B] This also allows you to get more shadows in your scene before the engine shits itself.

Here's how it works. When lighting your scene, you should be thinking about primary sources of light, and ambient sources (think actual lights/sun vs. blue sky and brown ground). As you place lights around your scene, set each group of lights to a different button, i.e. the sun lights to 9, ambient sky lighting to 8, headlights to 7, ambient light from the ground and stuff to 6, and so on. This is where we deviate from the usual screenshot procedure. Using a [B]STATIONARY CAMERA ON A FULL-DARK MAP[/B] (think gm_black), take a screenshot for EACH and EVERY source of light. It's a pain in the ass, but it's what you gotta do. Every picture should be nothing but the light (and shadows) cast by that particular set of lights. Do this for every set of lights. I also recommend doing one fullbright and on with all the lights on, just to be safe.

Once you've exited the game and are in photoshop, create a blank file that is the same resolution as your screenshots with a black background. Then, layer each image over top of eachother. Set ALL of their blending modes to "Screen" and you're done: Each image blends only the lit pixels over the one below it, effectively combining all of the images, their lights, and shadows. Now, by turning each layer on or off and/or changing its opacity, you can change the intensity (or even color, if you tint the layer) of each light in the scene. After you've taken the picture. Here's an example of all the pieces that went into one of my recent screenshots:

[URL="https://dl.dropboxusercontent.com/u/17239680/Facepunch/Tutorials/FlexibleLight/Example_Fullsize.jpg"][IMG]https://dl.dropboxusercontent.com/u/17239680/Facepunch/Tutorials/FlexibleLight/Example_Preview.jpg[/IMG][/URL]

That's a lot of work to go through for one image, but it gives you extreme flexibility in post, AND allows you to light massive scenes by doing only one light source at a time. Here's an example, where I remove the moonlight entirely, leaving only the lantern. Note that I took this screenshot weeks ago, and made this change today.

[URL="https://dl.dropboxusercontent.com/u/17239680/Facepunch/Tutorials/FlexibleLight/Change_Example.jpg"][IMG]https://dl.dropboxusercontent.com/u/17239680/Facepunch/Tutorials/FlexibleLight/Changed_Preview.jpg[/IMG][/URL]

So that's that. Hopefully this will help with those HUGE scenebuilds, or for people like me who can't decide on lighting. Just remember to make sure that each picture is EXACTLY THE SAME from an angle/dof standpoint. This method hinges on recreating the exact image over and over, so they can be layered. That's why I recommend taking one safety image with all the lights on, in case you screw up.

[Ott]

Is that entire scene props? Did you recompile the map with no lighting?

[SvenBrimstone]

[QUOTE=Ott;47849948]Is that entire scene props? Did you recompile the map with no lighting?[/QUOTE]

All props. I've been doing scene builds with all props for years now, simply because it gives me so much control over the image.

[Crazy Knife]

I should try this out. So basically, take pics with a particular light source and then set them as screen layers.

Question, is there a specific order of setting the screen lighting layers? I assume the mat_fullbright 1 layer is going to be the background layer?

[FlounderBox]

I remember someone posting similar advice ages ago. Might have been Joazzz.

Anyways, fantastic stuff.

[SvenBrimstone]

[QUOTE=Crazy Knife;47850006]I should try this out. So basically, take pics with a particular light source and then set them as screen layers.

Question, is there a specific order of setting the screen lighting layers? I assume the mat_fullbright 1 layer is going to be the background layer?[/QUOTE]

No order. And you honestly don't use the fullbright one (if you put it at the bottom or anywhere inbetween it'll ruin the image, because it will light everything up). I only take a fullbright one in case I have to paint in some details that simply are not lit in the other images. Sorry if that didn't make sense in the tutorial.

[rama2299]

Can the layer thing be used the same way in GIMP? Awesome tips btw

[Ott]

Can you upload one of your project files?

[Joazzz]

this is exactly what i do too

[KingGrim]

Been doing this since I saw Joazz's tutorial on blending images together via screens albeit not to this scale, I'll place 3-4 or four lights and assign them to a key, repeat the process a few times(for the background and foreground) then edit via photoshop. Gonna definitely start doing each light individually though.

[SvenBrimstone]

[QUOTE=Ott;47850398]Can you upload one of your project files?[/QUOTE]

I'll simplify one until it's a more manageable size, then throw it up on dropbox tonight.

[SvenBrimstone]

Here's a simplified version of the edit file (I had to combine some layers and the like to get the filesize down from ~200MB to ~40MB)

[url]https://dl.dropboxusercontent.com/u/17239680/Facepunch/Photoshop%20Contests/ScreenshotEdits/Swamp/Edit_Simplified.psd[/url]

[editline]1st June 2015[/editline]

If you want practice, manipulate the image to change the time of day, by tinting/brightening certain lights. It can be done, seeing as the layers are all from uncompressed TGAs and won't get weird artifacts if you bump up the brightness.