Eccentric Shading

Writing a custom lighting function in Godot means giving up the engine’s lighting entirely — and then spending a week trying to match it by eye. Objects shaded by your shader sit next to objects shaded by Godot’s, and they never quite belong to the same scene.

Eccentric Shading is the lighting model every Hyperreal surface uses. It starts from exact parity with Godot’s own lighting — same diffuse, same specular, same energy at every angle and roughness — so a material you write with it belongs in the scene from the first frame. Then it adds what photorealistic surfaces need and Godot doesn’t offer.

What it adds

• Subsurface scattering — strength, tint, thickness and falloff, for surfaces light actually passes through.
• Light wrap — the soft scatter of light bending around thin material. Grass blades, leaves, cloth.
• Sheen — the grazing sheen off fabric, moss and dry grass when the light is low and behind them.
• Per-fragment specularity — control Godot’s lighting function doesn’t expose at all.
• An alternative diffuse model for surfaces that need a rougher, more matte response than the default.

What it corrects

Godot’s own specular energy handling relies on data a user shader can’t reach. Every hand-written Godot lighting function is therefore slightly dimmer than the built-in path at grazing angles and high roughness — most visibly on rough metal. That is the reason custom Godot shaders so often look subtly off even when the maths is right.

Eccentric Shading closes that gap. Materials keep their intended brightness at every angle.

Where it’s used

Terrain uses it, which is where its per-material specularity, light wrap and sheen come from. Because the whole bundle shares one lighting model, a look you establish on terrain carries over to water and to cards without re-tuning.

You can use it in your own shaders too.