Intro

Cel Shading, a method of shading where the shadows and lights are sharp unlike the standard Smooth shading. Not to be confused with Outlines which are just lines and are NOT shading. To make this type of shading in SFM you can follow this guide! Please note that there are some requirements:

• Have a good understanding of SFM
• Have a photo editor like Photoshop, Gimp or Photopea.com
• Patience.

Setup

First, you need to load Black_Void, disable ambient occlusion and have your pose done, you will also need need to setup the model to be Cel Shaded. So remove all Bump Maps and reflections/shininess to not create additional, unnecessary detail. I will not cover that in here but you could look it up.

If your model isn't pitch black on darkness (like some of them that have Selfillum) just add $selfillum and set it's value to 0

Lighting

Now that we are ready to go, place your Key Light. Remap the Intensity slider range to 100000 and enable the Constant light, also bring down shadowDepthBias, shadowAtten and shadowFilterSize to 0 and lastly, make it Red.

Copy it, make it green and make a Mid Tones Light, to do this increase shadowFilterSize and Radius and ta-da! it is done!

Copy it again and make a rimlight and make it blue, again, increase just a little tiny bit the shadowFilterSize.

By now it should look like this:

Disable lighting (fullbright), render, re enable lighting and disable lights Now, put something white that glows in the dark, for this I recommend this Workshop Item Render and we are done

Post Processing

By now, you should have these renders:

If you do, then all good! Now, import fullbright into your preferred photo editor, in my case it's Photopea

Now import your mask as a layer, invert it (Ctrl + I in Photopea) and fix any gaps that aren't part of your actual render. Now go to Channels tab

And select the RGB channel

Return to the Layers tab again, select the Base layer and mask it

by now you should have this:

Right Click the Mask > Apply

Now import the Cel Mask and make 3 copies of the Base Layer, You should have it like this:

Select the main mask, make a new layer at the bottom and fill it with black or a very dark color Go to Channels again, select Red channel and apply it to Key, decrease transparency to 75% or so, now select Green channel, apply it to Midtones and decrease transparency to 50% and then select Blue channel and apply it to Rim, that's it. You should now have it like this:

You should make some fine tuning with layers by modifying the mask like I did because I couldn't remove Bump map.

Add some extra stuff that i won't cover here and you done!