Risk of Rain 2 Coloured Outline

Hey folks,
I picked up Risk of Rain 2 the other day (and have been loving it!) and have been fascinated by their inked outlines, after having created a very simple 1-colour outline in UE4 myself but finding it really lacking.
What in the world do you think they’re doing here to get the colours of the underlying material up into the outline? Is it some sort of low-value additive blend maybe?

I’m not an incredibly technical person, but always happy to learn so interested in what others might think :slight_smile:

Attaching a few cropped images with zoomed sections so you can get a decent view of what I’m talking about.

not how they did it, but, clone mesh, flip faces, push outwards, and you can make that geometry whatever colour your heart desires.

The outline on the foliage looks like it is mesh based to me given that the outline thickness is oriented with the surface normal.

This is the method I personally use: Local Outline FX Without Post-Processing in Unreal Engine – Tom Looman

It’s expensive if you plan on doing it for every object though

Yeh I’ve thought about the duped geo with inverted normals method, and how you could essentially just have the same diffuse textures assigned and set to an additive blend or something. Maybe you could get an interesting result.
But when I saw the foliage it seemed like that method wouldn’t work there? How would you get that sort of effect to cooperate with flat cards?

I’ve come across that Tom Looman effect a couple of times when digging around in different methods trying to find an approach I could use and it’s really interesting for sure, definitely the most advanced method I’ve seen (though I haven’t tried it firsthand) - the post regarding how Riot uses a similar method gives a little weight to the idea of potentially implementing it in a light-weight way, though like you said this is typically only applied to select objects but when a key part of the style as in RoR2 it’s on literally everything, so I’m not sure how you’d get that working.

Thanks for the ideas and discussion :slight_smile:

An interesting aspect of the bottom image is it almost looks like the texture of the object wraps onto the outline, possibly suggesting that the outline runs internal (my first thought was maybe it’s just some sort of tight, binary fresnel-driven effect to capture the outer edges of the asset but that would most likely give a much messier looking result than this)

Whenever i have an area that cloned geometry outlines aren’t really useful for (grass planes etc) I just paint it into the texture.