My Mini-Projects: Page 2 - Godot Community Forums

My Mini-Projects

cybereality

It was used a lot in Mario Galaxy. It makes the edges look glowing. Not realistic at all, it is more for cartoon games, but can make things look more 3D if they are too flat.

Bimbam

Had a quick look at rim lighting, but just made everything look varying levels of white. Probably needs a specific baked texture to work well, but tried normal map with little benefit.

In other news, uploaded a better quality fire vid:

The compression may butcher it as it's subtle, but there's now heat distortion and embers. Redid the sim but not applied it yet so should look more different next time.

Erich_L

I don't see it, is it on the tree? All I can look at is that hard edge on the log in the water. Fire looks amazing. Really nice work on the sound too m8

cybereality

So here is how rim can look.

Normal lighting:

Rim lighting:

Rim texture:

Note, you can adjust the colors or pattern on the rim texture, as well as the strength in the rim material properties to get the look you want. If you do it subtly it can add a lot of depth to a flat image.

xyz

The term "rim light" in photography means a light that's placed behind the subject and generally facing towards the camera thus causing sharp edge highlights on the subject (mostly of specular nature). You can create rim lighting in 3d simply by arranging regular lights.

In Godot shaders "rim" refers to an additive effect that lightens faces depending on the inclination angle in respect to view direction. This results in appearance similar to using actual rim lights but it's cheaper to calculate. It also doesn't produce any cast self-shadows so if overdone it might look like an image from an electron microscope.

Megalomaniak

@xyz said: The term "rim light" in photography means a light that's placed behind the subject and generally facing towards the camera thus causing sharp edge highlights on the subject (mostly of specular nature). You can create rim lighting in 3d simply by arranging regular lights.

And the proper physical effect is called Fresnel reflection and is a standard part of any PBR material and lighting system. Godot already features it too. Things actually look extremely unrealistic without it.

In fact @cybereality's Normal Lighting image example already features it but it just isn't cartoonishly blown out.

xyz

Technically, fresnel falloff pertains only to specular/polarizing reflections, however you can have rims on purely diffuse BRDFs, just less pronounced. It's more of an artistic term in my book, a matter of light positioning.

I don't think Godot's shader rim is actual PB fresnel though, as it seems that it doesn't care about light direction at all.

cybereality

Yes, it's a hack, but if you know the moon will always be in front of the player, then it can be done somewhat realistically. I personally wouldn't use it for a real looking game, but it can work for fantastical or stylized games.

xyz

Yeah it's definitely useful for whole range of neat effects.

Megalomaniak

In Lambertian shading it should apply to both specular and diffuse surfaces. This is for more computationally heavy and complex microsurfaced material. Think of a clay pot that has dried off but not polished off of the dust. Or something satin. Lamberian is however kind of an inverse of fresnel I suppose. The rim lighting might not come from backlight but instead from sides or front/head-on reflection.

xyz

Yeah, it can be caused by various things. That's why I consider "rim light" a perceptual term rather than technical.

I still can't figure out what precisely they do in "rim" section of Godot's spatial shader though. It looks like uniformly added brightness dependent only on total light intensity and viewing incidence of the normal. The actual fresnel is, I think, part of calculations in metalic/specular components of used PBR model.

Megalomaniak

@xyz said:

I still can't figure out what precisely they do in "rim" section of Godot's spatial shader though. It looks like uniformly added brightness dependent only on total light intensity and viewing incidence of the normal. The actual fresnel is, I think, part of calculations in metalic/specular components of used PBR model.

Yeah something like that. The specific Rim component is likely meant solely for more stylistic effect.

Bimbam

Ok so I may have made the scene temporarily even darker, but bear with it

Thoughts on the fire?

xyz

Fire is looking great!

TwistedTwigleg

I think the fire looks great! The sparks, smoke and glow around it really add to the effect.

cybereality

Nice!

Bimbam

I need something like Octahedral Imposters but for an AnimatedSprite3D Node >.< though I imagine I can hack a script together that does something similar based on a raycast to the fire and normal of face check to define which is visible.

Well, I didn't do it with a raycast, just took the X/Z axis of the fire and the camera and compared for the angle. But unfortunately options are limited on AnimatedSprite3D node as to how one would blend between each cardinal direction at the transition point, so it was very obvious when it flicked between North and North East for example.

My semi working way around THAT issue was to crank it up to 16 cameras in Blender:

Then use a function that determines cardinal direction to ensure only the 3 sprites most facing the camera were visible, and moderate the opacity to fall off as the camera moves.

Is it perfect? No. Is it even a particularly good way to do it? Still no. Will it work for this scene? Yeah I guess it's probably fine for a one-off.

cybereality

That's pretty cool. I think it would work for like a torch the character was holding, but maybe too much if there were like dozens of them in the scene. Or maybe not. Looks nice, though.

Bimbam

Another short update tying in background animations:

Still lots of annoyances to fix, but close to wrapping this one up.

cybereality

Looks great. Love it eyes.

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